qgsvectorlayer.cpp

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/***************************************************************************
                               qgsvectorlayer.cpp
                              --------------------
          begin                : Oct 29, 2003
          copyright            : (C) 2003 by Gary E.Sherman
          email                : sherman at mrcc.com
 
  This class implements a generic means to display vector layers. The features
  and attributes are read from the data store using a "data provider" plugin.
  QgsVectorLayer can be used with any data store for which an appropriate
  plugin is available.
 
***************************************************************************/
 
/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
 
#include "qgsvectorlayer.h"
 
#include <limits>
#include <memory>
#include <optional>
 
#include "qgis.h"
#include "qgsactionmanager.h"
#include "qgsapplication.h"
#include "qgsauxiliarystorage.h"
#include "qgsconditionalstyle.h"
#include "qgscoordinatereferencesystem.h"
#include "qgscurve.h"
#include "qgsdatasourceuri.h"
#include "qgsdiagramrenderer.h"
#include "qgsexpressioncontext.h"
#include "qgsexpressioncontextutils.h"
#include "qgsexpressionfieldbuffer.h"
#include "qgsexpressionnodeimpl.h"
#include "qgsfeature.h"
#include "qgsfeaturerenderergenerator.h"
#include "qgsfeaturerequest.h"
#include "qgsfeedback.h"
#include "qgsfields.h"
#include "qgsgeometry.h"
#include "qgsgeometryoptions.h"
#include "qgslayermetadataformatter.h"
#include "qgslogger.h"
#include "qgsmaplayerfactory.h"
#include "qgsmaplayerlegend.h"
#include "qgsmaplayerstylemanager.h"
#include "qgsmessagelog.h"
#include "qgsnetworkcontentfetcherregistry.h"
#include "qgsobjectvisitor.h"
#include "qgsogcutils.h"
#include "qgspainting.h"
#include "qgspallabeling.h"
#include "qgspoint.h"
#include "qgspointxy.h"
#include "qgsprofilerequest.h"
#include "qgsproject.h"
#include "qgsproviderregistry.h"
#include "qgsrectangle.h"
#include "qgsrelationmanager.h"
#include "qgsrendercontext.h"
#include "qgsrenderer.h"
#include "qgsrulebasedlabeling.h"
#include "qgsruntimeprofiler.h"
#include "qgssettingsentryenumflag.h"
#include "qgssettingsentryimpl.h"
#include "qgssettingstree.h"
#include "qgssldexportcontext.h"
#include "qgsstoredexpressionmanager.h"
#include "qgssymbollayer.h"
#include "qgssymbollayerutils.h"
#include "qgstaskmanager.h"
#include "qgsthreadingutils.h"
#include "qgstransaction.h"
#include "qgsvectordataprovider.h"
#include "qgsvectorlayereditbuffer.h"
#include "qgsvectorlayereditpassthrough.h"
#include "qgsvectorlayereditutils.h"
#include "qgsvectorlayerelevationproperties.h"
#include "qgsvectorlayerfeaturecounter.h"
#include "qgsvectorlayerfeatureiterator.h"
#include "qgsvectorlayerjoinbuffer.h"
#include "qgsvectorlayerlabeling.h"
#include "qgsvectorlayerprofilegenerator.h"
#include "qgsvectorlayerrenderer.h"
#include "qgsvectorlayerselectionproperties.h"
#include "qgsvectorlayertemporalproperties.h"
#include "qgsvectorlayerutils.h"
#include "qgsweakrelation.h"
#include "qgsxmlutils.h"
 
#include <QDir>
#include <QDomNode>
#include <QFile>
#include <QImage>
#include <QPainter>
#include <QPainterPath>
#include <QPolygonF>
#include <QProgressDialog>
#include <QRegularExpression>
#include <QString>
#include <QStringBuilder>
#include <QTimer>
#include <QUndoCommand>
#include <QUrl>
#include <QUrlQuery>
#include <QUuid>
#include <QVector>
 
#include "moc_qgsvectorlayer.cpp"
 
using namespace Qt::StringLiterals;
 
const QgsSettingsEntryDouble *QgsVectorLayer::settingsSimplifyDrawingTol = new QgsSettingsEntryDouble( u"simplifyDrawingTol"_s, QgsSettingsTree::sTreeQgis, Qgis::DEFAULT_MAPTOPIXEL_THRESHOLD );
const QgsSettingsEntryBool *QgsVectorLayer::settingsSimplifyLocal = new QgsSettingsEntryBool( u"simplifyLocal"_s, QgsSettingsTree::sTreeQgis, true );
const QgsSettingsEntryDouble *QgsVectorLayer::settingsSimplifyMaxScale = new QgsSettingsEntryDouble( u"simplifyMaxScale"_s, QgsSettingsTree::sTreeQgis, 1.0 );
const QgsSettingsEntryEnumFlag<Qgis::VectorRenderingSimplificationFlags> *QgsVectorLayer::settingsSimplifyDrawingHints
  = new QgsSettingsEntryEnumFlag<Qgis::VectorRenderingSimplificationFlags>( u"simplifyDrawingHints"_s, QgsSettingsTree::sTreeQgis, Qgis::VectorRenderingSimplificationFlag::NoSimplification );
const QgsSettingsEntryEnumFlag<Qgis::VectorSimplificationAlgorithm> *QgsVectorLayer::settingsSimplifyAlgorithm
  = new QgsSettingsEntryEnumFlag<Qgis::VectorSimplificationAlgorithm>( u"simplifyAlgorithm"_s, QgsSettingsTree::sTreeQgis, Qgis::VectorSimplificationAlgorithm::Distance );
 
 
#ifdef TESTPROVIDERLIB
#include <dlfcn.h>
#endif
 
typedef bool saveStyle_t(
  const QString &uri, const QString &qmlStyle, const QString &sldStyle, const QString &styleName, const QString &styleDescription, const QString &uiFileContent, bool useAsDefault, QString &errCause
);
 
typedef QString loadStyle_t( const QString &uri, QString &errCause );
 
typedef int listStyles_t( const QString &uri, QStringList &ids, QStringList &names, QStringList &descriptions, QString &errCause );
 
typedef QString getStyleById_t( const QString &uri, QString styleID, QString &errCause );
 
typedef bool deleteStyleById_t( const QString &uri, QString styleID, QString &errCause );
 
 
QgsVectorLayer::QgsVectorLayer( const QString &vectorLayerPath, const QString &baseName, const QString &providerKey, const QgsVectorLayer::LayerOptions &options )
  : QgsMapLayer( Qgis::LayerType::Vector, baseName, vectorLayerPath )
  , mSelectionProperties( new QgsVectorLayerSelectionProperties( this ) )
  , mTemporalProperties( new QgsVectorLayerTemporalProperties( this ) )
  , mElevationProperties( new QgsVectorLayerElevationProperties( this ) )
  , mAuxiliaryLayer( nullptr )
  , mAuxiliaryLayerKey( QString() )
  , mReadExtentFromXml( options.readExtentFromXml )
  , mRefreshRendererTimer( new QTimer( this ) )
{
  mShouldValidateCrs = !options.skipCrsValidation;
  mLoadAllStoredStyle = options.loadAllStoredStyles;
 
  if ( options.fallbackCrs.isValid() )
    setCrs( options.fallbackCrs, false );
  mWkbType = options.fallbackWkbType;
 
  setProviderType( providerKey );
 
  mGeometryOptions = std::make_unique<QgsGeometryOptions>();
  mActions = new QgsActionManager( this );
  mConditionalStyles = new QgsConditionalLayerStyles( this );
  mStoredExpressionManager = new QgsStoredExpressionManager();
  mStoredExpressionManager->setParent( this );
 
  mJoinBuffer = new QgsVectorLayerJoinBuffer( this );
  mJoinBuffer->setParent( this );
  connect( mJoinBuffer, &QgsVectorLayerJoinBuffer::joinedFieldsChanged, this, &QgsVectorLayer::onJoinedFieldsChanged );
 
  mExpressionFieldBuffer = new QgsExpressionFieldBuffer();
  // if we're given a provider type, try to create and bind one to this layer
  if ( !vectorLayerPath.isEmpty() && !mProviderKey.isEmpty() )
  {
    QgsDataProvider::ProviderOptions providerOptions { options.transformContext };
    Qgis::DataProviderReadFlags providerFlags;
    if ( options.loadDefaultStyle )
    {
      providerFlags |= Qgis::DataProviderReadFlag::LoadDefaultStyle;
    }
    if ( options.forceReadOnly )
    {
      providerFlags |= Qgis::DataProviderReadFlag::ForceReadOnly;
      mDataSourceReadOnly = true;
    }
    setDataSource( vectorLayerPath, baseName, providerKey, providerOptions, providerFlags );
  }
 
  for ( const QgsField &field : std::as_const( mFields ) )
  {
    if ( !mAttributeAliasMap.contains( field.name() ) )
      mAttributeAliasMap.insert( field.name(), QString() );
  }
 
  if ( isValid() )
  {
    mTemporalProperties->setDefaultsFromDataProviderTemporalCapabilities( mDataProvider->temporalCapabilities() );
    if ( !mTemporalProperties->isActive() )
    {
      // didn't populate temporal properties from provider metadata, so at least try to setup some initially nice
      // selections
      mTemporalProperties->guessDefaultsFromFields( mFields );
    }
 
    mElevationProperties->setDefaultsFromLayer( this );
  }
 
  connect( this, &QgsVectorLayer::selectionChanged, this, [this] { triggerRepaint(); } );
  connect( QgsProject::instance()->relationManager(), &QgsRelationManager::relationsLoaded, this, &QgsVectorLayer::onRelationsLoaded ); // skip-keyword-check
 
  connect( this, &QgsVectorLayer::subsetStringChanged, this, &QgsMapLayer::configChanged );
  connect( this, &QgsVectorLayer::dataSourceChanged, this, &QgsVectorLayer::supportsEditingChanged );
  connect( this, &QgsVectorLayer::readOnlyChanged, this, &QgsVectorLayer::supportsEditingChanged );
 
  // Default simplify drawing settings
  mSimplifyMethod.setSimplifyHints( QgsVectorLayer::settingsSimplifyDrawingHints->valueWithDefaultOverride( mSimplifyMethod.simplifyHints() ) );
  mSimplifyMethod.setSimplifyAlgorithm( QgsVectorLayer::settingsSimplifyAlgorithm->valueWithDefaultOverride( mSimplifyMethod.simplifyAlgorithm() ) );
  mSimplifyMethod.setThreshold( QgsVectorLayer::settingsSimplifyDrawingTol->valueWithDefaultOverride( mSimplifyMethod.threshold() ) );
  mSimplifyMethod.setForceLocalOptimization( QgsVectorLayer::settingsSimplifyLocal->valueWithDefaultOverride( mSimplifyMethod.forceLocalOptimization() ) );
  mSimplifyMethod.setMaximumScale( QgsVectorLayer::settingsSimplifyMaxScale->valueWithDefaultOverride( mSimplifyMethod.maximumScale() ) );
 
  connect( mRefreshRendererTimer, &QTimer::timeout, this, [this] { triggerRepaint( true ); } );
}
 
QgsVectorLayer::~QgsVectorLayer()
{
  emit willBeDeleted();
 
  setValid( false );
 
  delete mDataProvider;
  delete mEditBuffer;
  delete mJoinBuffer;
  delete mExpressionFieldBuffer;
  delete mLabeling;
  delete mDiagramLayerSettings;
  delete mDiagramRenderer;
 
  delete mActions;
 
  delete mRenderer;
  delete mConditionalStyles;
  delete mStoredExpressionManager;
 
  if ( mFeatureCounter )
    mFeatureCounter->cancel();
 
  qDeleteAll( mRendererGenerators );
}
 
QgsVectorLayer *QgsVectorLayer::clone() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QgsVectorLayer::LayerOptions options;
  // We get the data source string from the provider when
  // possible because some providers may have changed it
  // directly (memory provider does that).
  QString dataSource;
  if ( mDataProvider )
  {
    dataSource = mDataProvider->dataSourceUri();
    options.transformContext = mDataProvider->transformContext();
  }
  else
  {
    dataSource = source();
  }
  options.forceReadOnly = mDataSourceReadOnly;
  QgsVectorLayer *layer = new QgsVectorLayer( dataSource, name(), mProviderKey, options );
  if ( mDataProvider && layer->dataProvider() )
  {
    layer->dataProvider()->handlePostCloneOperations( mDataProvider );
  }
  QgsMapLayer::clone( layer );
  layer->mXmlExtent2D = mXmlExtent2D;
  layer->mLazyExtent2D = mLazyExtent2D;
  layer->mValidExtent2D = mValidExtent2D;
  layer->mXmlExtent3D = mXmlExtent3D;
  layer->mLazyExtent3D = mLazyExtent3D;
  layer->mValidExtent3D = mValidExtent3D;
 
  QList<QgsVectorLayerJoinInfo> joins = vectorJoins();
  const auto constJoins = joins;
  for ( const QgsVectorLayerJoinInfo &join : constJoins )
  {
    // do not copy join information for auxiliary layer
    if ( !auxiliaryLayer() || ( auxiliaryLayer() && auxiliaryLayer()->id() != join.joinLayerId() ) )
      layer->addJoin( join );
  }
 
  if ( mDataProvider )
    layer->setProviderEncoding( mDataProvider->encoding() );
  layer->setSubsetString( subsetString() );
  layer->setDisplayExpression( displayExpression() );
  layer->setMapTipTemplate( mapTipTemplate() );
  layer->setMapTipsEnabled( mapTipsEnabled() );
  layer->setReadOnly( isReadOnly() );
  layer->selectByIds( selectedFeatureIds() );
  layer->setAttributeTableConfig( attributeTableConfig() );
  layer->setFeatureBlendMode( featureBlendMode() );
  layer->setReadExtentFromXml( readExtentFromXml() );
 
  const auto constActions = actions()->actions();
  for ( const QgsAction &action : constActions )
  {
    layer->actions()->addAction( action );
  }
 
  if ( auto *lRenderer = renderer() )
  {
    layer->setRenderer( lRenderer->clone() );
  }
 
  if ( auto *lLabeling = labeling() )
  {
    layer->setLabeling( lLabeling->clone() );
  }
  layer->setLabelsEnabled( labelsEnabled() );
 
  layer->setSimplifyMethod( simplifyMethod() );
 
  if ( auto *lDiagramRenderer = diagramRenderer() )
  {
    layer->setDiagramRenderer( lDiagramRenderer->clone() );
  }
 
  if ( auto *lDiagramLayerSettings = diagramLayerSettings() )
  {
    layer->setDiagramLayerSettings( *lDiagramLayerSettings );
  }
 
  for ( int i = 0; i < fields().count(); i++ )
  {
    layer->setFieldAlias( i, attributeAlias( i ) );
    layer->setFieldConfigurationFlags( i, fieldConfigurationFlags( i ) );
    layer->setEditorWidgetSetup( i, editorWidgetSetup( i ) );
    layer->setConstraintExpression( i, constraintExpression( i ), constraintDescription( i ) );
    layer->setDefaultValueDefinition( i, defaultValueDefinition( i ) );
 
    QMap< QgsFieldConstraints::Constraint, QgsFieldConstraints::ConstraintStrength> constraints = fieldConstraintsAndStrength( i );
    auto constraintIt = constraints.constBegin();
    for ( ; constraintIt != constraints.constEnd(); ++constraintIt )
    {
      layer->setFieldConstraint( i, constraintIt.key(), constraintIt.value() );
    }
 
    if ( fields().fieldOrigin( i ) == Qgis::FieldOrigin::Expression )
    {
      layer->addExpressionField( expressionField( i ), fields().at( i ) );
    }
  }
 
  layer->setEditFormConfig( editFormConfig() );
 
  if ( auto *lAuxiliaryLayer = auxiliaryLayer() )
    layer->setAuxiliaryLayer( lAuxiliaryLayer->clone( layer ) );
 
  layer->mElevationProperties = mElevationProperties->clone();
  layer->mElevationProperties->setParent( layer );
 
  layer->mSelectionProperties = mSelectionProperties->clone();
  layer->mSelectionProperties->setParent( layer );
 
  return layer;
}
 
QString QgsVectorLayer::storageType() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( mDataProvider )
  {
    return mDataProvider->storageType();
  }
  return QString();
}
 
 
QString QgsVectorLayer::capabilitiesString() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( mDataProvider )
  {
    return mDataProvider->capabilitiesString();
  }
  return QString();
}
 
bool QgsVectorLayer::isSqlQuery() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return mDataProvider && mDataProvider->isSqlQuery();
}
 
Qgis::VectorLayerTypeFlags QgsVectorLayer::vectorLayerTypeFlags() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return mDataProvider ? mDataProvider->vectorLayerTypeFlags() : Qgis::VectorLayerTypeFlags();
}
 
QString QgsVectorLayer::dataComment() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( mDataProvider )
  {
    return mDataProvider->dataComment();
  }
  return QString();
}
 
QgsCoordinateReferenceSystem QgsVectorLayer::sourceCrs() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return crs();
}
 
QString QgsVectorLayer::sourceName() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return name();
}
 
void QgsVectorLayer::reload()
{
  // non fatal for now -- the QgsVirtualLayerTask class is not thread safe and calls this
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS_NON_FATAL
 
  if ( mDataProvider )
  {
    mDataProvider->reloadData();
    updateFields();
  }
}
 
QgsMapLayerRenderer *QgsVectorLayer::createMapRenderer( QgsRenderContext &rendererContext )
{
  // non fatal for now -- the "rasterize" processing algorithm is not thread safe and calls this
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS_NON_FATAL
 
  return new QgsVectorLayerRenderer( this, rendererContext );
}
 
 
void QgsVectorLayer::drawVertexMarker( double x, double y, QPainter &p, Qgis::VertexMarkerType type, int m )
{
  switch ( type )
  {
    case Qgis::VertexMarkerType::SemiTransparentCircle:
      p.setPen( QColor( 50, 100, 120, 200 ) );
      p.setBrush( QColor( 200, 200, 210, 120 ) );
      p.drawEllipse( x - m, y - m, m * 2 + 1, m * 2 + 1 );
      break;
 
    case Qgis::VertexMarkerType::Cross:
      p.setPen( QColor( 255, 0, 0 ) );
      p.drawLine( x - m, y + m, x + m, y - m );
      p.drawLine( x - m, y - m, x + m, y + m );
      break;
 
    case Qgis::VertexMarkerType::NoMarker:
      break;
  }
}
 
void QgsVectorLayer::select( QgsFeatureId fid )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  mSelectedFeatureIds.insert( fid );
  mPreviousSelectedFeatureIds.clear();
 
  emit selectionChanged( QgsFeatureIds() << fid, QgsFeatureIds(), false );
}
 
void QgsVectorLayer::select( const QgsFeatureIds &featureIds )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  mSelectedFeatureIds.unite( featureIds );
  mPreviousSelectedFeatureIds.clear();
 
  emit selectionChanged( featureIds, QgsFeatureIds(), false );
}
 
void QgsVectorLayer::deselect( const QgsFeatureId fid )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  mSelectedFeatureIds.remove( fid );
  mPreviousSelectedFeatureIds.clear();
 
  emit selectionChanged( QgsFeatureIds(), QgsFeatureIds() << fid, false );
}
 
void QgsVectorLayer::deselect( const QgsFeatureIds &featureIds )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  mSelectedFeatureIds.subtract( featureIds );
  mPreviousSelectedFeatureIds.clear();
 
  emit selectionChanged( QgsFeatureIds(), featureIds, false );
}
 
void QgsVectorLayer::selectByRect( const QgsRectangle &rect, Qgis::SelectBehavior behavior )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  // normalize the rectangle
  QgsRectangle normalizedRect = rect;
  normalizedRect.normalize();
 
  QgsFeatureIds newSelection;
 
  QgsFeatureIterator features = getFeatures(
    QgsFeatureRequest().setFilterRect( normalizedRect ).setFlags( Qgis::FeatureRequestFlag::ExactIntersect | Qgis::FeatureRequestFlag::NoGeometry ).setNoAttributes()
  );
 
  QgsFeature feat;
  while ( features.nextFeature( feat ) )
  {
    newSelection << feat.id();
  }
  features.close();
 
  selectByIds( newSelection, behavior );
}
 
void QgsVectorLayer::selectByExpression( const QString &expression, Qgis::SelectBehavior behavior, QgsExpressionContext *context )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QgsFeatureIds newSelection;
 
  std::optional< QgsExpressionContext > defaultContext;
  if ( !context )
  {
    defaultContext.emplace( QgsExpressionContextUtils::globalProjectLayerScopes( this ) );
    context = &defaultContext.value();
  }
  else
  {
    context->appendScope( QgsExpressionContextUtils::layerScope( this ) );
  }
 
  QgsExpression exp( expression );
  exp.prepare( context );
 
  if ( behavior == Qgis::SelectBehavior::SetSelection || behavior == Qgis::SelectBehavior::AddToSelection )
  {
    QgsFeatureRequest request = QgsFeatureRequest().setFilterExpression( expression ).setExpressionContext( *context );
    request.setSubsetOfAttributes( exp.referencedColumns(), fields() );
 
    if ( !exp.needsGeometry() )
      request.setFlags( Qgis::FeatureRequestFlag::NoGeometry );
 
    QgsFeatureIterator features = getFeatures( request );
 
    if ( behavior == Qgis::SelectBehavior::AddToSelection )
    {
      newSelection = selectedFeatureIds();
    }
    QgsFeature feat;
    while ( features.nextFeature( feat ) )
    {
      newSelection << feat.id();
    }
    features.close();
  }
  else if ( behavior == Qgis::SelectBehavior::IntersectSelection || behavior == Qgis::SelectBehavior::RemoveFromSelection )
  {
    QgsFeatureIds oldSelection = selectedFeatureIds();
    QgsFeatureRequest request = QgsFeatureRequest().setFilterFids( oldSelection );
 
    //refine request
    if ( !exp.needsGeometry() )
      request.setFlags( Qgis::FeatureRequestFlag::NoGeometry );
    request.setSubsetOfAttributes( exp.referencedColumns(), fields() );
 
    QgsFeatureIterator features = getFeatures( request );
    QgsFeature feat;
    while ( features.nextFeature( feat ) )
    {
      context->setFeature( feat );
      bool matches = exp.evaluate( context ).toBool();
 
      if ( matches && behavior == Qgis::SelectBehavior::IntersectSelection )
      {
        newSelection << feat.id();
      }
      else if ( !matches && behavior == Qgis::SelectBehavior::RemoveFromSelection )
      {
        newSelection << feat.id();
      }
    }
  }
 
  selectByIds( newSelection );
}
 
void QgsVectorLayer::selectByIds( const QgsFeatureIds &ids, Qgis::SelectBehavior behavior, bool validateIds )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  // Opt-in validation: filter invalid IDs if requested
  QgsFeatureIds idsToSelect = ids;
  if ( validateIds )
  {
    idsToSelect = QgsVectorLayerUtils::filterValidFeatureIds( this, ids );
  }
 
  QgsFeatureIds newSelection;
 
  switch ( behavior )
  {
    case Qgis::SelectBehavior::SetSelection:
      newSelection = idsToSelect;
      break;
 
    case Qgis::SelectBehavior::AddToSelection:
      newSelection = mSelectedFeatureIds + idsToSelect;
      break;
 
    case Qgis::SelectBehavior::RemoveFromSelection:
      newSelection = mSelectedFeatureIds - idsToSelect;
      break;
 
    case Qgis::SelectBehavior::IntersectSelection:
      newSelection = mSelectedFeatureIds.intersect( idsToSelect );
      break;
  }
 
  QgsFeatureIds deselectedFeatures = mSelectedFeatureIds - newSelection;
  mSelectedFeatureIds = newSelection;
  mPreviousSelectedFeatureIds.clear();
 
  emit selectionChanged( newSelection, deselectedFeatures, true );
}
 
void QgsVectorLayer::modifySelection( const QgsFeatureIds &selectIds, const QgsFeatureIds &deselectIds )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QgsFeatureIds intersectingIds = selectIds & deselectIds;
  if ( !intersectingIds.isEmpty() )
  {
    QgsDebugMsgLevel( u"Trying to select and deselect the same item at the same time. Unsure what to do. Selecting dubious items."_s, 3 );
  }
 
  mSelectedFeatureIds -= deselectIds;
  mSelectedFeatureIds += selectIds;
  mPreviousSelectedFeatureIds.clear();
 
  emit selectionChanged( selectIds, deselectIds - intersectingIds, false );
}
 
void QgsVectorLayer::invertSelection()
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QgsFeatureIds ids = allFeatureIds();
  ids.subtract( mSelectedFeatureIds );
  selectByIds( ids );
}
 
void QgsVectorLayer::selectAll()
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  selectByIds( allFeatureIds() );
}
 
void QgsVectorLayer::invertSelectionInRectangle( const QgsRectangle &rect )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  // normalize the rectangle
  QgsRectangle normalizedRect = rect;
  normalizedRect.normalize();
 
  QgsFeatureIterator fit = getFeatures( QgsFeatureRequest().setFilterRect( normalizedRect ).setFlags( Qgis::FeatureRequestFlag::NoGeometry | Qgis::FeatureRequestFlag::ExactIntersect ).setNoAttributes() );
 
  QgsFeatureIds selectIds;
  QgsFeatureIds deselectIds;
 
  QgsFeature fet;
  while ( fit.nextFeature( fet ) )
  {
    if ( mSelectedFeatureIds.contains( fet.id() ) )
    {
      deselectIds << fet.id();
    }
    else
    {
      selectIds << fet.id();
    }
  }
 
  modifySelection( selectIds, deselectIds );
}
 
void QgsVectorLayer::removeSelection()
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( mSelectedFeatureIds.isEmpty() )
    return;
 
  const QgsFeatureIds previous = mSelectedFeatureIds;
  selectByIds( QgsFeatureIds() );
  mPreviousSelectedFeatureIds = previous;
}
 
void QgsVectorLayer::reselect()
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( mPreviousSelectedFeatureIds.isEmpty() || !mSelectedFeatureIds.empty() )
    return;
 
  selectByIds( mPreviousSelectedFeatureIds );
}
 
QgsVectorDataProvider *QgsVectorLayer::dataProvider()
{
  // non fatal for now -- the "rasterize" processing algorithm is not thread safe and calls this
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS_NON_FATAL
 
  return mDataProvider;
}
 
const QgsVectorDataProvider *QgsVectorLayer::dataProvider() const
{
  // non fatal for now -- the "rasterize" processing algorithm is not thread safe and calls this
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS_NON_FATAL
 
  return mDataProvider;
}
 
QgsMapLayerSelectionProperties *QgsVectorLayer::selectionProperties()
{
  // non fatal for now -- the "rasterize" processing algorithm is not thread safe and calls this
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS_NON_FATAL
 
  return mSelectionProperties;
}
 
QgsMapLayerTemporalProperties *QgsVectorLayer::temporalProperties()
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return mTemporalProperties;
}
 
QgsMapLayerElevationProperties *QgsVectorLayer::elevationProperties()
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return mElevationProperties;
}
 
QgsAbstractProfileGenerator *QgsVectorLayer::createProfileGenerator( const QgsProfileRequest &request )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QgsProfileRequest modifiedRequest( request );
  modifiedRequest.expressionContext().appendScope( createExpressionContextScope() );
  return new QgsVectorLayerProfileGenerator( this, modifiedRequest );
}
 
void QgsVectorLayer::setProviderEncoding( const QString &encoding )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( isValid() && mDataProvider && mDataProvider->encoding() != encoding )
  {
    mDataProvider->setEncoding( encoding );
    updateFields();
  }
}
 
void QgsVectorLayer::setDiagramRenderer( QgsDiagramRenderer *r )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  delete mDiagramRenderer;
  mDiagramRenderer = r;
  emit rendererChanged();
  emit styleChanged();
}
 
Qgis::GeometryType QgsVectorLayer::geometryType() const
{
  // non fatal for now -- the "rasterize" processing algorithm is not thread safe and calls this
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS_NON_FATAL
 
  return QgsWkbTypes::geometryType( mWkbType );
}
 
Qgis::WkbType QgsVectorLayer::wkbType() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return mWkbType;
}
 
QgsRectangle QgsVectorLayer::boundingBoxOfSelected() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !isValid() || !isSpatial() || mSelectedFeatureIds.isEmpty() || !mDataProvider ) //no selected features
  {
    return QgsRectangle( 0, 0, 0, 0 );
  }
 
  QgsRectangle r, retval;
  retval.setNull();
 
  QgsFeature fet;
  if ( mDataProvider->capabilities() & Qgis::VectorProviderCapability::SelectAtId )
  {
    QgsFeatureIterator fit = getFeatures( QgsFeatureRequest().setFilterFids( mSelectedFeatureIds ).setNoAttributes() );
 
    while ( fit.nextFeature( fet ) )
    {
      if ( !fet.hasGeometry() )
        continue;
      r = fet.geometry().boundingBox();
      retval.combineExtentWith( r );
    }
  }
  else
  {
    QgsFeatureIterator fit = getFeatures( QgsFeatureRequest().setNoAttributes() );
 
    while ( fit.nextFeature( fet ) )
    {
      if ( mSelectedFeatureIds.contains( fet.id() ) )
      {
        if ( fet.hasGeometry() )
        {
          r = fet.geometry().boundingBox();
          retval.combineExtentWith( r );
        }
      }
    }
  }
 
  if ( retval.width() == 0.0 || retval.height() == 0.0 )
  {
    // If all of the features are at the one point, buffer the
    // rectangle a bit. If they are all at zero, do something a bit
    // more crude.
 
    if ( retval.xMinimum() == 0.0 && retval.xMaximum() == 0.0 && retval.yMinimum() == 0.0 && retval.yMaximum() == 0.0 )
    {
      retval.set( -1.0, -1.0, 1.0, 1.0 );
    }
  }
 
  return retval;
}
 
bool QgsVectorLayer::labelsEnabled() const
{
  // non fatal for now -- the "rasterize" processing algorithm is not thread safe and calls this
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS_NON_FATAL
 
  return mLabelsEnabled && static_cast< bool >( mLabeling );
}
 
void QgsVectorLayer::setLabelsEnabled( bool enabled )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  mLabelsEnabled = enabled;
}
 
bool QgsVectorLayer::diagramsEnabled() const
{
  // non fatal for now -- the "rasterize" processing algorithm is not thread safe and calls this
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS_NON_FATAL
 
  if ( !mDiagramRenderer || !mDiagramLayerSettings )
    return false;
 
  QList<QgsDiagramSettings> settingList = mDiagramRenderer->diagramSettings();
  if ( !settingList.isEmpty() )
  {
    return settingList.at( 0 ).enabled;
  }
  return false;
}
 
long long QgsVectorLayer::featureCount( const QString &legendKey ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !mSymbolFeatureCounted )
    return -1;
 
  return mSymbolFeatureCountMap.value( legendKey, -1 );
}
 
QgsFeatureIds QgsVectorLayer::symbolFeatureIds( const QString &legendKey ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !mSymbolFeatureCounted )
    return QgsFeatureIds();
 
  return mSymbolFeatureIdMap.value( legendKey, QgsFeatureIds() );
}
QgsVectorLayerFeatureCounter *QgsVectorLayer::countSymbolFeatures( bool storeSymbolFids )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( ( mSymbolFeatureCounted || mFeatureCounter ) && !( storeSymbolFids && mSymbolFeatureIdMap.isEmpty() ) )
    return mFeatureCounter;
 
  mSymbolFeatureCountMap.clear();
  mSymbolFeatureIdMap.clear();
 
  if ( !isValid() )
  {
    QgsDebugMsgLevel( u"invoked with invalid layer"_s, 3 );
    return mFeatureCounter;
  }
  if ( !mDataProvider )
  {
    QgsDebugMsgLevel( u"invoked with null mDataProvider"_s, 3 );
    return mFeatureCounter;
  }
  if ( !mRenderer )
  {
    QgsDebugMsgLevel( u"invoked with null mRenderer"_s, 3 );
    return mFeatureCounter;
  }
 
  if ( !mFeatureCounter || ( storeSymbolFids && mSymbolFeatureIdMap.isEmpty() ) )
  {
    mFeatureCounter = new QgsVectorLayerFeatureCounter( this, QgsExpressionContext(), storeSymbolFids );
    connect( mFeatureCounter, &QgsTask::taskCompleted, this, &QgsVectorLayer::onFeatureCounterCompleted, Qt::UniqueConnection );
    connect( mFeatureCounter, &QgsTask::taskTerminated, this, &QgsVectorLayer::onFeatureCounterTerminated, Qt::UniqueConnection );
    QgsApplication::taskManager()->addTask( mFeatureCounter );
  }
 
  return mFeatureCounter;
}
 
void QgsVectorLayer::updateExtents( bool force )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  // do not update extent by default when trust project option is activated
  if ( force || !mReadExtentFromXml || ( mReadExtentFromXml && mXmlExtent2D.isNull() && mXmlExtent3D.isNull() ) )
  {
    mValidExtent2D = false;
    mValidExtent3D = false;
  }
}
 
void QgsVectorLayer::setExtent( const QgsRectangle &r )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QgsMapLayer::setExtent( r );
  mValidExtent2D = true;
}
 
void QgsVectorLayer::setExtent3D( const QgsBox3D &r )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QgsMapLayer::setExtent3D( r );
  mValidExtent3D = true;
}
 
void QgsVectorLayer::updateDefaultValues( QgsFeatureId fid, QgsFeature feature, QgsExpressionContext *context )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !mDefaultValueOnUpdateFields.isEmpty() )
  {
    if ( !feature.isValid() )
      feature = getFeature( fid );
 
    int size = mFields.size();
    for ( int idx : std::as_const( mDefaultValueOnUpdateFields ) )
    {
      if ( idx < 0 || idx >= size )
        continue;
      feature.setAttribute( idx, defaultValue( idx, feature, context ) );
      updateFeature( feature, true );
    }
  }
}
 
QgsRectangle QgsVectorLayer::extent() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QgsRectangle rect;
  rect.setNull();
 
  if ( !isSpatial() )
    return rect;
 
  // Don't do lazy extent if the layer is currently in edit mode
  if ( mLazyExtent2D && isEditable() )
    mLazyExtent2D = false;
 
  if ( mDataProvider && mDataProvider->isValid() && ( mDataProvider->flags() & Qgis::DataProviderFlag::FastExtent2D ) )
  {
    // Provider has a trivial 2D extent calculation => always get extent from provider.
    // Things are nice and simple this way, e.g. we can always trust that this extent is
    // accurate and up to date.
    updateExtent( mDataProvider->extent() );
    mValidExtent2D = true;
    mLazyExtent2D = false;
  }
  else
  {
    if ( !mValidExtent2D && mLazyExtent2D && mReadExtentFromXml && !mXmlExtent2D.isNull() )
    {
      updateExtent( mXmlExtent2D );
      mValidExtent2D = true;
      mLazyExtent2D = false;
    }
 
    if ( !mValidExtent2D && mLazyExtent2D && mDataProvider && mDataProvider->isValid() )
    {
      // store the extent
      updateExtent( mDataProvider->extent() );
      mValidExtent2D = true;
      mLazyExtent2D = false;
 
      // show the extent
      QgsDebugMsgLevel( u"2D Extent of layer: %1"_s.arg( mExtent2D.toString() ), 3 );
    }
  }
 
  if ( mValidExtent2D )
    return QgsMapLayer::extent();
 
  if ( !isValid() || !mDataProvider )
  {
    QgsDebugMsgLevel( u"invoked with invalid layer or null mDataProvider"_s, 3 );
    return rect;
  }
 
  if ( !mEditBuffer
       || ( !mDataProvider->transaction() && ( mEditBuffer->deletedFeatureIds().isEmpty() && mEditBuffer->changedGeometries().isEmpty() ) )
       || QgsDataSourceUri( mDataProvider->dataSourceUri() ).useEstimatedMetadata() )
  {
    mDataProvider->updateExtents();
 
    // get the extent of the layer from the provider
    // but only when there are some features already
    if ( mDataProvider->featureCount() != 0 )
    {
      const QgsRectangle r = mDataProvider->extent();
      rect.combineExtentWith( r );
    }
 
    if ( mEditBuffer && !mDataProvider->transaction() )
    {
      const auto addedFeatures = mEditBuffer->addedFeatures();
      for ( QgsFeatureMap::const_iterator it = addedFeatures.constBegin(); it != addedFeatures.constEnd(); ++it )
      {
        if ( it->hasGeometry() )
        {
          const QgsRectangle r = it->geometry().boundingBox();
          rect.combineExtentWith( r );
        }
      }
    }
  }
  else
  {
    QgsFeatureIterator fit = getFeatures( QgsFeatureRequest().setNoAttributes() );
 
    QgsFeature fet;
    while ( fit.nextFeature( fet ) )
    {
      if ( fet.hasGeometry() && fet.geometry().type() != Qgis::GeometryType::Unknown )
      {
        const QgsRectangle bb = fet.geometry().boundingBox();
        rect.combineExtentWith( bb );
      }
    }
  }
 
  if ( rect.xMinimum() > rect.xMaximum() && rect.yMinimum() > rect.yMaximum() )
  {
    // special case when there are no features in provider nor any added
    rect = QgsRectangle(); // use rectangle with zero coordinates
  }
 
  updateExtent( rect );
  mValidExtent2D = true;
 
  // Send this (hopefully) up the chain to the map canvas
  emit recalculateExtents();
 
  return rect;
}
 
QgsBox3D QgsVectorLayer::extent3D() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  // if data is 2D, redirect to 2D extend computation, and save it as 2D extent (in 3D bbox)
  if ( mDataProvider && mDataProvider->elevationProperties() && !mDataProvider->elevationProperties()->containsElevationData() )
  {
    return QgsBox3D( extent() );
  }
 
  QgsBox3D extent;
  extent.setNull();
 
  if ( !isSpatial() )
    return extent;
 
  if ( mDataProvider && mDataProvider->isValid() && ( mDataProvider->flags() & Qgis::DataProviderFlag::FastExtent3D ) )
  {
    // Provider has a trivial 3D extent calculation => always get extent from provider.
    // Things are nice and simple this way, e.g. we can always trust that this extent is
    // accurate and up to date.
    updateExtent( mDataProvider->extent3D() );
    mValidExtent3D = true;
    mLazyExtent3D = false;
  }
  else
  {
    if ( !mValidExtent3D && mLazyExtent3D && mReadExtentFromXml && !mXmlExtent3D.isNull() )
    {
      updateExtent( mXmlExtent3D );
      mValidExtent3D = true;
      mLazyExtent3D = false;
    }
 
    if ( !mValidExtent3D && mLazyExtent3D && mDataProvider && mDataProvider->isValid() )
    {
      // store the extent
      updateExtent( mDataProvider->extent3D() );
      mValidExtent3D = true;
      mLazyExtent3D = false;
 
      // show the extent
      QgsDebugMsgLevel( u"3D Extent of layer: %1"_s.arg( mExtent3D.toString() ), 3 );
    }
  }
 
  if ( mValidExtent3D )
    return QgsMapLayer::extent3D();
 
  if ( !isValid() || !mDataProvider )
  {
    QgsDebugMsgLevel( u"invoked with invalid layer or null mDataProvider"_s, 3 );
    return extent;
  }
 
  if ( !mEditBuffer
       || ( !mDataProvider->transaction() && ( mEditBuffer->deletedFeatureIds().isEmpty() && mEditBuffer->changedGeometries().isEmpty() ) )
       || QgsDataSourceUri( mDataProvider->dataSourceUri() ).useEstimatedMetadata() )
  {
    mDataProvider->updateExtents();
 
    // get the extent of the layer from the provider
    // but only when there are some features already
    if ( mDataProvider->featureCount() != 0 )
    {
      const QgsBox3D ext = mDataProvider->extent3D();
      extent.combineWith( ext );
    }
 
    if ( mEditBuffer && !mDataProvider->transaction() )
    {
      const auto addedFeatures = mEditBuffer->addedFeatures();
      for ( QgsFeatureMap::const_iterator it = addedFeatures.constBegin(); it != addedFeatures.constEnd(); ++it )
      {
        if ( it->hasGeometry() )
        {
          const QgsBox3D bbox = it->geometry().boundingBox3D();
          extent.combineWith( bbox );
        }
      }
    }
  }
  else
  {
    QgsFeatureIterator fit = getFeatures( QgsFeatureRequest().setNoAttributes() );
 
    QgsFeature fet;
    while ( fit.nextFeature( fet ) )
    {
      if ( fet.hasGeometry() && fet.geometry().type() != Qgis::GeometryType::Unknown )
      {
        const QgsBox3D bb = fet.geometry().boundingBox3D();
        extent.combineWith( bb );
      }
    }
  }
 
  if ( extent.xMinimum() > extent.xMaximum() && extent.yMinimum() > extent.yMaximum() && extent.zMinimum() > extent.zMaximum() )
  {
    // special case when there are no features in provider nor any added
    extent = QgsBox3D(); // use rectangle with zero coordinates
  }
 
  updateExtent( extent );
  mValidExtent3D = true;
 
  // Send this (hopefully) up the chain to the map canvas
  emit recalculateExtents();
 
  return extent;
}
 
QgsRectangle QgsVectorLayer::sourceExtent() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return extent();
}
 
QgsBox3D QgsVectorLayer::sourceExtent3D() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return extent3D();
}
 
QString QgsVectorLayer::subsetString() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !isValid() || !mDataProvider )
  {
    QgsDebugMsgLevel( u"invoked with invalid layer or null mDataProvider"_s, 3 );
    return customProperty( u"storedSubsetString"_s ).toString();
  }
  return mDataProvider->subsetString();
}
 
bool QgsVectorLayer::setSubsetString( const QString &subset )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !isValid() || !mDataProvider )
  {
    QgsDebugMsgLevel( u"invoked with invalid layer or null mDataProvider or while editing"_s, 3 );
    setCustomProperty( u"storedSubsetString"_s, subset );
    return false;
  }
  else if ( mEditBuffer )
  {
    QgsDebugMsgLevel( u"invoked while editing"_s, 3 );
    return false;
  }
 
  if ( subset == mDataProvider->subsetString() )
    return true;
 
  bool res = mDataProvider->setSubsetString( subset );
 
  // get the updated data source string from the provider
  mDataSource = mDataProvider->dataSourceUri();
  updateExtents();
  updateFields();
 
  if ( res )
  {
    emit subsetStringChanged();
    triggerRepaint();
  }
 
  return res;
}
 
bool QgsVectorLayer::simplifyDrawingCanbeApplied( const QgsRenderContext &renderContext, Qgis::VectorRenderingSimplificationFlag simplifyHint ) const
{
  // non fatal for now -- the "rasterize" processing algorithm is not thread safe and calls this
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS_NON_FATAL
 
  if ( isValid()
       && mDataProvider
       && !mEditBuffer
       && ( isSpatial() && geometryType() != Qgis::GeometryType::Point )
       && ( mSimplifyMethod.simplifyHints() & simplifyHint )
       && renderContext.useRenderingOptimization() )
  {
    double maximumSimplificationScale = mSimplifyMethod.maximumScale();
 
    // check maximum scale at which generalisation should be carried out
    return !( maximumSimplificationScale > 1 && renderContext.rendererScale() <= maximumSimplificationScale );
  }
  return false;
}
 
QgsConditionalLayerStyles *QgsVectorLayer::conditionalStyles() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return mConditionalStyles;
}
 
QgsFeatureIterator QgsVectorLayer::getFeatures( const QgsFeatureRequest &request ) const
{
  // non fatal for now -- the aggregate expression functions are not thread safe and call this
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS_NON_FATAL
 
  if ( !isValid() || !mDataProvider )
    return QgsFeatureIterator();
 
  return QgsFeatureIterator( new QgsVectorLayerFeatureIterator( new QgsVectorLayerFeatureSource( this ), true, request ) );
}
 
QgsGeometry QgsVectorLayer::getGeometry( QgsFeatureId fid ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QgsFeature feature;
  getFeatures( QgsFeatureRequest( fid ).setFlags( Qgis::FeatureRequestFlag::SubsetOfAttributes ) ).nextFeature( feature );
  if ( feature.isValid() )
    return feature.geometry();
  else
    return QgsGeometry();
}
 
bool QgsVectorLayer::addFeature( QgsFeature &feature, Flags )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !isValid() || !mEditBuffer || !mDataProvider )
    return false;
 
 
  if ( mGeometryOptions->isActive() )
  {
    QgsGeometry geom = feature.geometry();
    mGeometryOptions->apply( geom );
    feature.setGeometry( geom );
  }
 
  bool success = mEditBuffer->addFeature( feature );
 
  if ( success && mJoinBuffer->containsJoins() )
  {
    success = mJoinBuffer->addFeature( feature );
  }
 
  return success;
}
 
bool QgsVectorLayer::updateFeature( QgsFeature &updatedFeature, bool skipDefaultValues )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !mEditBuffer || !mDataProvider )
  {
    return false;
  }
 
  QgsFeature currentFeature = getFeature( updatedFeature.id() );
  if ( currentFeature.isValid() )
  {
    bool hasChanged = false;
    bool hasError = false;
 
    if ( ( updatedFeature.hasGeometry() || currentFeature.hasGeometry() ) && !updatedFeature.geometry().isExactlyEqual( currentFeature.geometry() ) )
    {
      QgsGeometry geometry = updatedFeature.geometry();
      if ( changeGeometry( updatedFeature.id(), geometry, true ) )
      {
        hasChanged = true;
        updatedFeature.setGeometry( geometry );
      }
      else
      {
        QgsDebugMsgLevel( u"geometry of feature %1 could not be changed."_s.arg( updatedFeature.id() ), 3 );
      }
    }
 
    QgsAttributes fa = updatedFeature.attributes();
    QgsAttributes ca = currentFeature.attributes();
 
    for ( int attr = 0; attr < fa.count(); ++attr )
    {
      if ( !qgsVariantEqual( fa.at( attr ), ca.at( attr ) ) )
      {
        if ( changeAttributeValue( updatedFeature.id(), attr, fa.at( attr ), ca.at( attr ), true ) )
        {
          hasChanged = true;
        }
        else
        {
          QgsDebugMsgLevel( u"attribute %1 of feature %2 could not be changed."_s.arg( attr ).arg( updatedFeature.id() ), 3 );
          hasError = true;
        }
      }
    }
    if ( hasChanged && !mDefaultValueOnUpdateFields.isEmpty() && !skipDefaultValues )
      updateDefaultValues( updatedFeature.id(), updatedFeature );
 
    return !hasError;
  }
  else
  {
    QgsDebugMsgLevel( u"feature %1 could not be retrieved"_s.arg( updatedFeature.id() ), 3 );
    return false;
  }
}
 
 
bool QgsVectorLayer::insertVertex( double x, double y, QgsFeatureId atFeatureId, int beforeVertex )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !isValid() || !mEditBuffer || !mDataProvider )
    return false;
 
  QgsVectorLayerEditUtils utils( this );
  bool result = utils.insertVertex( x, y, atFeatureId, beforeVertex );
  if ( result )
    updateExtents();
  return result;
}
 
 
bool QgsVectorLayer::insertVertex( const QgsPoint &point, QgsFeatureId atFeatureId, int beforeVertex )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !isValid() || !mEditBuffer || !mDataProvider )
    return false;
 
  QgsVectorLayerEditUtils utils( this );
  bool result = utils.insertVertex( point, atFeatureId, beforeVertex );
  if ( result )
    updateExtents();
  return result;
}
 
 
bool QgsVectorLayer::moveVertex( double x, double y, QgsFeatureId atFeatureId, int atVertex )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !isValid() || !mEditBuffer || !mDataProvider )
    return false;
 
  QgsVectorLayerEditUtils utils( this );
  bool result = utils.moveVertex( x, y, atFeatureId, atVertex );
 
  if ( result )
    updateExtents();
  return result;
}
 
bool QgsVectorLayer::moveVertex( const QgsPoint &p, QgsFeatureId atFeatureId, int atVertex )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !isValid() || !mEditBuffer || !mDataProvider )
    return false;
 
  QgsVectorLayerEditUtils utils( this );
  bool result = utils.moveVertex( p, atFeatureId, atVertex );
 
  if ( result )
    updateExtents();
  return result;
}
 
Qgis::VectorEditResult QgsVectorLayer::deleteVertex( QgsFeatureId featureId, int vertex )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !isValid() || !mEditBuffer || !mDataProvider )
    return Qgis::VectorEditResult::InvalidLayer;
 
  QgsVectorLayerEditUtils utils( this );
  Qgis::VectorEditResult result = utils.deleteVertex( featureId, vertex );
 
  if ( result == Qgis::VectorEditResult::Success )
    updateExtents();
  return result;
}
 
 
bool QgsVectorLayer::deleteSelectedFeatures( int *deletedCount, QgsVectorLayer::DeleteContext *context )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !isValid() || !mDataProvider || !( mDataProvider->capabilities() & Qgis::VectorProviderCapability::DeleteFeatures ) )
  {
    return false;
  }
 
  if ( !isEditable() )
  {
    return false;
  }
 
  int deleted = 0;
  int count = mSelectedFeatureIds.size();
  // Make a copy since deleteFeature modifies mSelectedFeatureIds
  QgsFeatureIds selectedFeatures( mSelectedFeatureIds );
  for ( QgsFeatureId fid : std::as_const( selectedFeatures ) )
  {
    deleted += deleteFeature( fid, context ); // removes from selection
  }
 
  triggerRepaint();
  updateExtents();
 
  if ( deletedCount )
  {
    *deletedCount = deleted;
  }
 
  return deleted == count;
}
 
static const QgsPointSequence vectorPointXY2pointSequence( const QVector<QgsPointXY> &points )
{
  QgsPointSequence pts;
  pts.reserve( points.size() );
  QVector<QgsPointXY>::const_iterator it = points.constBegin();
  while ( it != points.constEnd() )
  {
    pts.append( QgsPoint( *it ) );
    ++it;
  }
  return pts;
}
Qgis::GeometryOperationResult QgsVectorLayer::addRing( const QVector<QgsPointXY> &ring, QgsFeatureId *featureId )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return addRing( vectorPointXY2pointSequence( ring ), featureId );
}
 
Qgis::GeometryOperationResult QgsVectorLayer::addRing( const QgsPointSequence &ring, QgsFeatureId *featureId )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !isValid() || !mEditBuffer || !mDataProvider )
    return Qgis::GeometryOperationResult::LayerNotEditable;
 
  QgsVectorLayerEditUtils utils( this );
  Qgis::GeometryOperationResult result = Qgis::GeometryOperationResult::AddRingNotInExistingFeature;
 
  //first try with selected features
  if ( !mSelectedFeatureIds.isEmpty() )
  {
    result = utils.addRing( ring, mSelectedFeatureIds, featureId );
  }
 
  if ( result != Qgis::GeometryOperationResult::Success )
  {
    //try with all intersecting features
    result = utils.addRing( ring, QgsFeatureIds(), featureId );
  }
 
  return result;
}
 
Qgis::GeometryOperationResult QgsVectorLayer::addRing( QgsCurve *ring, QgsFeatureId *featureId )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !isValid() || !mEditBuffer || !mDataProvider )
  {
    delete ring;
    return Qgis::GeometryOperationResult::LayerNotEditable;
  }
 
  if ( !ring )
  {
    return Qgis::GeometryOperationResult::InvalidInputGeometryType;
  }
 
  if ( !ring->isClosed() )
  {
    delete ring;
    return Qgis::GeometryOperationResult::AddRingNotClosed;
  }
 
  QgsVectorLayerEditUtils utils( this );
  Qgis::GeometryOperationResult result = Qgis::GeometryOperationResult::AddRingNotInExistingFeature;
 
  //first try with selected features
  if ( !mSelectedFeatureIds.isEmpty() )
  {
    result = utils.addRing( static_cast< QgsCurve * >( ring->clone() ), mSelectedFeatureIds, featureId );
  }
 
  if ( result != Qgis::GeometryOperationResult::Success )
  {
    //try with all intersecting features
    result = utils.addRing( static_cast< QgsCurve * >( ring->clone() ), QgsFeatureIds(), featureId );
  }
 
  delete ring;
  return result;
}
 
Qgis::GeometryOperationResult QgsVectorLayer::addPart( const QList<QgsPointXY> &points )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QgsPointSequence pts;
  pts.reserve( points.size() );
  for ( QList<QgsPointXY>::const_iterator it = points.constBegin(); it != points.constEnd(); ++it )
  {
    pts.append( QgsPoint( *it ) );
  }
  return addPart( pts );
}
 
Qgis::GeometryOperationResult QgsVectorLayer::addPart( const QgsPointSequence &points )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !isValid() || !mEditBuffer || !mDataProvider )
    return Qgis::GeometryOperationResult::LayerNotEditable;
 
  //number of selected features must be 1
 
  if ( mSelectedFeatureIds.empty() )
  {
    QgsDebugMsgLevel( u"Number of selected features <1"_s, 3 );
    return Qgis::GeometryOperationResult::SelectionIsEmpty;
  }
  else if ( mSelectedFeatureIds.size() > 1 )
  {
    QgsDebugMsgLevel( u"Number of selected features >1"_s, 3 );
    return Qgis::GeometryOperationResult::SelectionIsGreaterThanOne;
  }
 
  QgsVectorLayerEditUtils utils( this );
  Qgis::GeometryOperationResult result = utils.addPart( points, *mSelectedFeatureIds.constBegin() );
 
  if ( result == Qgis::GeometryOperationResult::Success )
    updateExtents();
  return result;
}
 
Qgis::GeometryOperationResult QgsVectorLayer::addPart( QgsCurve *ring )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !isValid() || !mEditBuffer || !mDataProvider )
    return Qgis::GeometryOperationResult::LayerNotEditable;
 
  //number of selected features must be 1
 
  if ( mSelectedFeatureIds.empty() )
  {
    QgsDebugMsgLevel( u"Number of selected features <1"_s, 3 );
    return Qgis::GeometryOperationResult::SelectionIsEmpty;
  }
  else if ( mSelectedFeatureIds.size() > 1 )
  {
    QgsDebugMsgLevel( u"Number of selected features >1"_s, 3 );
    return Qgis::GeometryOperationResult::SelectionIsGreaterThanOne;
  }
 
  QgsVectorLayerEditUtils utils( this );
  Qgis::GeometryOperationResult result = utils.addPart( ring, *mSelectedFeatureIds.constBegin() );
 
  if ( result == Qgis::GeometryOperationResult::Success )
    updateExtents();
  return result;
}
 
// TODO QGIS 5.0 -- this should return Qgis::GeometryOperationResult, not int
int QgsVectorLayer::translateFeature( QgsFeatureId featureId, double dx, double dy )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !isValid() || !mEditBuffer || !mDataProvider )
    return static_cast< int >( Qgis::GeometryOperationResult::LayerNotEditable );
 
  QgsVectorLayerEditUtils utils( this );
  int result = utils.translateFeature( featureId, dx, dy );
 
  if ( result == static_cast< int >( Qgis::GeometryOperationResult::Success ) )
    updateExtents();
  return result;
}
 
Qgis::GeometryOperationResult QgsVectorLayer::splitParts( const QVector<QgsPointXY> &splitLine, bool topologicalEditing )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return splitParts( vectorPointXY2pointSequence( splitLine ), topologicalEditing );
}
 
Qgis::GeometryOperationResult QgsVectorLayer::splitParts( const QgsPointSequence &splitLine, bool topologicalEditing )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !isValid() || !mEditBuffer || !mDataProvider )
    return Qgis::GeometryOperationResult::LayerNotEditable;
 
  QgsVectorLayerEditUtils utils( this );
  return utils.splitParts( splitLine, topologicalEditing );
}
 
Qgis::GeometryOperationResult QgsVectorLayer::splitFeatures( const QVector<QgsPointXY> &splitLine, bool topologicalEditing )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return splitFeatures( vectorPointXY2pointSequence( splitLine ), topologicalEditing );
}
 
Qgis::GeometryOperationResult QgsVectorLayer::splitFeatures( const QgsPointSequence &splitLine, bool topologicalEditing )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QgsLineString splitLineString( splitLine );
  QgsPointSequence topologyTestPoints;
  bool preserveCircular = false;
  return splitFeatures( &splitLineString, topologyTestPoints, preserveCircular, topologicalEditing );
}
 
Qgis::GeometryOperationResult QgsVectorLayer::splitFeatures( const QgsCurve *curve, QgsPointSequence &topologyTestPoints, bool preserveCircular, bool topologicalEditing )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !isValid() || !mEditBuffer || !mDataProvider )
    return Qgis::GeometryOperationResult::LayerNotEditable;
 
  QgsVectorLayerEditUtils utils( this );
  return utils.splitFeatures( curve, topologyTestPoints, preserveCircular, topologicalEditing );
}
 
int QgsVectorLayer::addTopologicalPoints( const QgsGeometry &geom )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !isValid() || !mEditBuffer || !mDataProvider )
    return -1;
 
  QgsVectorLayerEditUtils utils( this );
  return utils.addTopologicalPoints( geom );
}
 
int QgsVectorLayer::addTopologicalPoints( const QgsPointXY &p )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return addTopologicalPoints( QgsPoint( p ) );
}
 
int QgsVectorLayer::addTopologicalPoints( const QgsPoint &p )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !isValid() || !mEditBuffer || !mDataProvider )
    return -1;
 
  QgsVectorLayerEditUtils utils( this );
  return utils.addTopologicalPoints( p );
}
 
int QgsVectorLayer::addTopologicalPoints( const QgsPointSequence &ps )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !mValid || !mEditBuffer || !mDataProvider )
    return -1;
 
  QgsVectorLayerEditUtils utils( this );
  return utils.addTopologicalPoints( ps );
}
 
void QgsVectorLayer::setLabeling( QgsAbstractVectorLayerLabeling *labeling )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( mLabeling == labeling )
    return;
 
  delete mLabeling;
  mLabeling = labeling;
}
 
bool QgsVectorLayer::startEditing()
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( project() && project()->transactionMode() == Qgis::TransactionMode::BufferedGroups )
    return project()->startEditing( this );
 
  if ( !isValid() || !mDataProvider )
  {
    return false;
  }
 
  // allow editing if provider supports any of the capabilities
  if ( !supportsEditing() )
  {
    return false;
  }
 
  if ( mEditBuffer )
  {
    // editing already underway
    return false;
  }
 
  mDataProvider->enterUpdateMode();
 
  emit beforeEditingStarted();
 
  createEditBuffer();
 
  updateFields();
 
  emit editingStarted();
 
  return true;
}
 
void QgsVectorLayer::setTransformContext( const QgsCoordinateTransformContext &transformContext )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( mDataProvider )
    mDataProvider->setTransformContext( transformContext );
}
 
Qgis::SpatialIndexPresence QgsVectorLayer::hasSpatialIndex() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return mDataProvider ? mDataProvider->hasSpatialIndex() : Qgis::SpatialIndexPresence::Unknown;
}
 
bool QgsVectorLayer::accept( QgsStyleEntityVisitorInterface *visitor ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( mRenderer )
    if ( !mRenderer->accept( visitor ) )
      return false;
 
  if ( mLabeling )
    if ( !mLabeling->accept( visitor ) )
      return false;
 
  return true;
}
 
bool QgsVectorLayer::accept( QgsObjectEntityVisitorInterface *visitor, const QgsObjectVisitorContext &context ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( mActions )
  {
    const QList<QgsAction> actions = mActions->actions();
    for ( const QgsAction &action : actions )
    {
      if ( action.command().isEmpty() )
      {
        continue;
      }
 
      switch ( action.type() )
      {
        case Qgis::AttributeActionType::GenericPython:
        case Qgis::AttributeActionType::Mac:
        case Qgis::AttributeActionType::Windows:
        case Qgis::AttributeActionType::Unix:
        {
          QgsEmbeddedScriptEntity entity( Qgis::EmbeddedScriptType::Action, tr( "%1: Action ’%2’" ).arg( name(), action.name() ), action.command() );
          if ( !visitor->visitEmbeddedScript( entity, context ) )
          {
            return false;
          }
          break;
        }
 
        case Qgis::AttributeActionType::Generic:
        case Qgis::AttributeActionType::OpenUrl:
        case Qgis::AttributeActionType::SubmitUrlEncoded:
        case Qgis::AttributeActionType::SubmitUrlMultipart:
        {
          break;
        }
      }
    }
  }
 
  QString initCode;
  switch ( mEditFormConfig.initCodeSource() )
  {
    case Qgis::AttributeFormPythonInitCodeSource::Dialog:
    {
      initCode = u"# Calling function ’%1’\n\n%2"_s.arg( mEditFormConfig.initFunction(), mEditFormConfig.initCode() );
      break;
    }
 
    case Qgis::AttributeFormPythonInitCodeSource::File:
    {
      QFile *inputFile = QgsApplication::networkContentFetcherRegistry()->localFile( mEditFormConfig.initFilePath() );
      if ( inputFile && inputFile->open( QFile::ReadOnly ) )
      {
        // Read it into a string
        QTextStream inf( inputFile );
        initCode = inf.readAll();
        inputFile->close();
        initCode = u"# Calling function ’%1’\n# From file %2\n\n"_s.arg( mEditFormConfig.initFunction(), mEditFormConfig.initFilePath() ) + initCode;
      }
      break;
    }
 
    case Qgis::AttributeFormPythonInitCodeSource::Environment:
    {
      initCode = u"# Calling function ’%1’\n# From environment\n\n"_s.arg( mEditFormConfig.initFunction() );
      break;
    }
 
    case Qgis::AttributeFormPythonInitCodeSource::NoSource:
    {
      break;
    }
  }
 
  if ( !initCode.isEmpty() )
  {
    QgsEmbeddedScriptEntity entity( Qgis::EmbeddedScriptType::FormInitCode, tr( "%1: Attribute form init code" ).arg( name() ), initCode );
    if ( !visitor->visitEmbeddedScript( entity, context ) )
    {
      return false;
    }
  }
 
  return true;
}
 
bool QgsVectorLayer::readXml( const QDomNode &layer_node, QgsReadWriteContext &context )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QgsDebugMsgLevel( u"Datasource in QgsVectorLayer::readXml: %1"_s.arg( mDataSource.toLocal8Bit().data() ), 3 );
 
  //process provider key
  QDomNode pkeyNode = layer_node.namedItem( u"provider"_s );
 
  if ( pkeyNode.isNull() )
  {
    mProviderKey.clear();
  }
  else
  {
    QDomElement pkeyElt = pkeyNode.toElement();
    mProviderKey = pkeyElt.text();
  }
 
  // determine type of vector layer
  if ( !mProviderKey.isNull() )
  {
    // if the provider string isn't empty, then we successfully
    // got the stored provider
  }
  else if ( mDataSource.contains( "dbname="_L1 ) )
  {
    mProviderKey = u"postgres"_s;
  }
  else
  {
    mProviderKey = u"ogr"_s;
  }
 
  const QDomElement elem = layer_node.toElement();
  QgsDataProvider::ProviderOptions options { context.transformContext() };
 
  mDataSourceReadOnly = mReadFlags & QgsMapLayer::FlagForceReadOnly;
  Qgis::DataProviderReadFlags flags = providerReadFlags( layer_node, mReadFlags );
 
  if ( ( mReadFlags & QgsMapLayer::FlagDontResolveLayers ) || !setDataProvider( mProviderKey, options, flags ) )
  {
    if ( !( mReadFlags & QgsMapLayer::FlagDontResolveLayers ) )
    {
      QgsDebugError( u"Could not set data provider for layer %1"_s.arg( publicSource() ) );
    }
 
    // for invalid layer sources, we fallback to stored wkbType if available
    if ( elem.hasAttribute( u"wkbType"_s ) )
      mWkbType = qgsEnumKeyToValue( elem.attribute( u"wkbType"_s ), mWkbType );
  }
 
  QDomElement pkeyElem = pkeyNode.toElement();
  if ( !pkeyElem.isNull() )
  {
    QString encodingString = pkeyElem.attribute( u"encoding"_s );
    if ( mDataProvider && !encodingString.isEmpty() )
    {
      mDataProvider->setEncoding( encodingString );
    }
  }
 
  // load vector joins - does not resolve references to layers yet
  mJoinBuffer->readXml( layer_node );
 
  updateFields();
 
  // If style doesn't include a legend, we'll need to make a default one later...
  mSetLegendFromStyle = false;
 
  QString errorMsg;
  if ( !readSymbology( layer_node, errorMsg, context ) )
  {
    return false;
  }
 
  readStyleManager( layer_node );
 
  QDomNode depsNode = layer_node.namedItem( u"dataDependencies"_s );
  QDomNodeList depsNodes = depsNode.childNodes();
  QSet<QgsMapLayerDependency> sources;
  for ( int i = 0; i < depsNodes.count(); i++ )
  {
    QString source = depsNodes.at( i ).toElement().attribute( u"id"_s );
    sources << QgsMapLayerDependency( source );
  }
  setDependencies( sources );
 
  if ( !mSetLegendFromStyle )
    setLegend( QgsMapLayerLegend::defaultVectorLegend( this ) );
 
  // read extent
  if ( mReadFlags & QgsMapLayer::FlagReadExtentFromXml )
  {
    mReadExtentFromXml = true;
  }
  if ( mReadExtentFromXml )
  {
    const QDomNode extentNode = layer_node.namedItem( u"extent"_s );
    if ( !extentNode.isNull() )
    {
      mXmlExtent2D = QgsXmlUtils::readRectangle( extentNode.toElement() );
    }
    const QDomNode extent3DNode = layer_node.namedItem( u"extent3D"_s );
    if ( !extent3DNode.isNull() )
    {
      mXmlExtent3D = QgsXmlUtils::readBox3D( extent3DNode.toElement() );
    }
  }
 
  // auxiliary layer
  const QDomNode asNode = layer_node.namedItem( u"auxiliaryLayer"_s );
  const QDomElement asElem = asNode.toElement();
  if ( !asElem.isNull() )
  {
    mAuxiliaryLayerKey = asElem.attribute( u"key"_s );
  }
 
  // QGIS Server WMS Dimensions
  mServerProperties->readXml( layer_node );
 
  return isValid(); // should be true if read successfully
 
} // void QgsVectorLayer::readXml
 
 
void QgsVectorLayer::setDataSourcePrivate( const QString &dataSource, const QString &baseName, const QString &provider, const QgsDataProvider::ProviderOptions &options, Qgis::DataProviderReadFlags flags )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  Qgis::GeometryType geomType = geometryType();
 
  mDataSource = dataSource;
  setName( baseName );
  setDataProvider( provider, options, flags );
 
  if ( !isValid() )
  {
    return;
  }
 
  // Always set crs
  setCoordinateSystem();
 
  bool loadDefaultStyleFlag = false;
  if ( flags & Qgis::DataProviderReadFlag::LoadDefaultStyle )
  {
    loadDefaultStyleFlag = true;
  }
 
  // reset style if loading default style, style is missing, or geometry type is has changed (and layer is valid)
  if ( !renderer() || !legend() || ( isValid() && geomType != geometryType() ) || loadDefaultStyleFlag )
  {
    std::unique_ptr< QgsScopedRuntimeProfile > profile;
    if ( QgsApplication::profiler()->groupIsActive( u"projectload"_s ) )
      profile = std::make_unique< QgsScopedRuntimeProfile >( tr( "Load layer style" ), u"projectload"_s );
 
    bool defaultLoadedFlag = false;
 
    // defer style changed signal until we've set the renderer, labeling, everything.
    // we don't want multiple signals!
    ScopedIntIncrementor styleChangedSignalBlocker( &mBlockStyleChangedSignal );
 
    // need to check whether the default style included a legend, and if not, we need to make a default legend
    // later...
    mSetLegendFromStyle = false;
 
    // first check if there is a default style / propertysheet defined
    // for this layer and if so apply it
    // this should take precedence over all
    if ( !defaultLoadedFlag && loadDefaultStyleFlag )
    {
      loadDefaultStyle( defaultLoadedFlag );
    }
 
    if ( loadDefaultStyleFlag && !defaultLoadedFlag && isSpatial() && mDataProvider->capabilities() & Qgis::VectorProviderCapability::CreateRenderer )
    {
      // if we didn't load a default style for this layer, try to create a renderer directly from the data provider
      std::unique_ptr< QgsFeatureRenderer > defaultRenderer( mDataProvider->createRenderer() );
      if ( defaultRenderer )
      {
        defaultLoadedFlag = true;
        setRenderer( defaultRenderer.release() );
      }
    }
 
    // if the default style failed to load or was disabled use some very basic defaults
    if ( !defaultLoadedFlag )
    {
      // add single symbol renderer for spatial layers
      setRenderer( isSpatial() ? QgsFeatureRenderer::defaultRenderer( geometryType() ) : nullptr );
    }
 
    if ( !mSetLegendFromStyle )
      setLegend( QgsMapLayerLegend::defaultVectorLegend( this ) );
 
    if ( mDataProvider->capabilities() & Qgis::VectorProviderCapability::CreateLabeling )
    {
      std::unique_ptr< QgsAbstractVectorLayerLabeling > defaultLabeling( mDataProvider->createLabeling() );
      if ( defaultLabeling )
      {
        setLabeling( defaultLabeling.release() );
        setLabelsEnabled( true );
      }
    }
 
    styleChangedSignalBlocker.release();
    emitStyleChanged();
  }
}
 
QString QgsVectorLayer::loadDefaultStyle( bool &resultFlag )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  // first try to load a user-defined default style - this should always take precedence
  QString styleXml = QgsMapLayer::loadDefaultStyle( resultFlag );
 
  if ( resultFlag )
  {
    // Try to load all stored styles from DB
    if ( mLoadAllStoredStyle && mDataProvider && mDataProvider->styleStorageCapabilities().testFlag( Qgis::ProviderStyleStorageCapability::LoadFromDatabase ) )
    {
      QStringList ids, names, descriptions;
      QString errorMessage;
      // Get the number of styles related to current layer.
      const int relatedStylesCount { listStylesInDatabase( ids, names, descriptions, errorMessage ) };
      Q_ASSERT( ids.count() == names.count() );
      const QString currentStyleName { mStyleManager->currentStyle() };
      for ( int i = 0; i < relatedStylesCount; ++i )
      {
        if ( names.at( i ) == currentStyleName )
        {
          continue;
        }
        errorMessage.clear();
        const QString styleXml { getStyleFromDatabase( ids.at( i ), errorMessage ) };
        if ( !styleXml.isEmpty() && errorMessage.isEmpty() )
        {
          mStyleManager->addStyle( names.at( i ), QgsMapLayerStyle( styleXml ) );
        }
        else
        {
          QgsDebugMsgLevel( u"Error retrieving style %1 from DB: %2"_s.arg( ids.at( i ), errorMessage ), 2 );
        }
      }
    }
    return styleXml;
  }
 
  if ( isSpatial() && mDataProvider->capabilities() & Qgis::VectorProviderCapability::CreateRenderer )
  {
    // otherwise try to create a renderer directly from the data provider
    std::unique_ptr< QgsFeatureRenderer > defaultRenderer( mDataProvider->createRenderer() );
    if ( defaultRenderer )
    {
      resultFlag = true;
      setRenderer( defaultRenderer.release() );
      return QString();
    }
  }
 
  return QString();
}
 
bool QgsVectorLayer::setDataProvider( QString const &provider, const QgsDataProvider::ProviderOptions &options, Qgis::DataProviderReadFlags flags )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  mProviderKey = provider;
  delete mDataProvider;
 
  // For Postgres provider primary key unicity is tested at construction time,
  // so it has to be set before initializing the provider,
  // this manipulation is necessary to preserve default behavior when
  // "trust layer metadata" project level option is set and checkPrimaryKeyUnicity
  // was not explicitly passed in the uri
  if ( provider.compare( "postgres"_L1 ) == 0 )
  {
    const QString checkUnicityKey { u"checkPrimaryKeyUnicity"_s };
    QgsDataSourceUri uri( mDataSource );
    if ( !uri.hasParam( checkUnicityKey ) )
    {
      uri.setParam( checkUnicityKey, mReadExtentFromXml ? "0" : "1" );
      mDataSource = uri.uri( false );
    }
  }
 
  std::unique_ptr< QgsScopedRuntimeProfile > profile;
  if ( QgsApplication::profiler()->groupIsActive( u"projectload"_s ) )
    profile = std::make_unique< QgsScopedRuntimeProfile >( tr( "Create %1 provider" ).arg( provider ), u"projectload"_s );
 
  if ( mPreloadedProvider )
  {
    QgsDebugMsgLevel( u"Attaching map layer %1 to preloaded data provider. Provider belongs to thread %2"_s.arg( id(), QgsThreadingUtils::threadDescription( mPreloadedProvider->thread() ) ), 2 );
    mDataProvider = qobject_cast< QgsVectorDataProvider * >( mPreloadedProvider.release() );
  }
  else
  {
    mDataProvider = qobject_cast<QgsVectorDataProvider *>( QgsProviderRegistry::instance()->createProvider( provider, mDataSource, options, flags ) );
  }
 
  if ( !mDataProvider )
  {
    setValid( false );
    QgsDebugMsgLevel( u"Unable to get data provider"_s, 2 );
    return false;
  }
 
  mDataProvider->setParent( this );
  connect( mDataProvider, &QgsVectorDataProvider::raiseError, this, &QgsVectorLayer::raiseError );
 
  QgsDebugMsgLevel( u"Instantiated the data provider plugin"_s, 2 );
 
  setValid( mDataProvider->isValid() );
  if ( !isValid() )
  {
    QgsDebugMsgLevel( u"Invalid provider plugin %1"_s.arg( QString( mDataSource.toUtf8() ) ), 2 );
    return false;
  }
 
  if ( profile )
    profile->switchTask( tr( "Read layer metadata" ) );
  if ( mDataProvider->capabilities() & Qgis::VectorProviderCapability::ReadLayerMetadata )
  {
    // we combine the provider metadata with the layer's existing metadata, so as not to reset any user customizations to the metadata
    // back to the default if a layer's data source is changed
    QgsLayerMetadata newMetadata = mDataProvider->layerMetadata();
    // this overwrites the provider metadata with any properties which are non-empty from the existing layer metadata
    newMetadata.combine( &mMetadata );
 
    setMetadata( newMetadata );
    QgsDebugMsgLevel( u"Set Data provider QgsLayerMetadata identifier[%1]"_s.arg( metadata().identifier() ), 4 );
  }
 
  // TODO: Check if the provider has the capability to send fullExtentCalculated
  connect( mDataProvider, &QgsVectorDataProvider::fullExtentCalculated, this, [this] { updateExtents(); } );
 
  // get and store the feature type
  mWkbType = mDataProvider->wkbType();
 
  // before we update the layer fields from the provider, we first copy any default set alias and
  // editor widget config from the data provider fields, if present
  const QgsFields providerFields = mDataProvider->fields();
  for ( const QgsField &field : providerFields )
  {
    // we only copy defaults from the provider if we aren't overriding any configuration made in the layer
    if ( !field.editorWidgetSetup().isNull() && mFieldWidgetSetups.value( field.name() ).isNull() )
    {
      mFieldWidgetSetups[field.name()] = field.editorWidgetSetup();
    }
    if ( !field.alias().isEmpty() && mAttributeAliasMap.value( field.name() ).isEmpty() )
    {
      mAttributeAliasMap[field.name()] = field.alias();
    }
    if ( !mAttributeSplitPolicy.contains( field.name() ) )
    {
      mAttributeSplitPolicy[field.name()] = field.splitPolicy();
    }
    if ( !mAttributeDuplicatePolicy.contains( field.name() ) )
    {
      mAttributeDuplicatePolicy[field.name()] = field.duplicatePolicy();
    }
    if ( !mAttributeMergePolicy.contains( field.name() ) )
    {
      mAttributeMergePolicy[field.name()] = field.mergePolicy();
    }
  }
 
  if ( profile )
    profile->switchTask( tr( "Read layer fields" ) );
  updateFields();
 
  if ( mProviderKey == "postgres"_L1 )
  {
    // update datasource from data provider computed one
    mDataSource = mDataProvider->dataSourceUri( false );
 
    QgsDebugMsgLevel( u"Beautifying layer name %1"_s.arg( name() ), 3 );
 
    // adjust the display name for postgres layers
    const thread_local QRegularExpression reg( R"lit("[^"]+"\."([^"] + )"( \‍([^)]+\))?)lit" );
    const QRegularExpressionMatch match = reg.match( name() );
    if ( match.hasMatch() )
    {
      QStringList stuff = match.capturedTexts();
      QString lName = stuff[1];
 
      const QMap<QString, QgsMapLayer *> &layers = QgsProject::instance()->mapLayers(); // skip-keyword-check
 
      QMap<QString, QgsMapLayer *>::const_iterator it;
      for ( it = layers.constBegin(); it != layers.constEnd() && ( *it )->name() != lName; ++it )
        ;
 
      if ( it != layers.constEnd() && stuff.size() > 2 )
      {
        lName += '.' + stuff[2].mid( 2, stuff[2].length() - 3 );
      }
 
      if ( !lName.isEmpty() )
        setName( lName );
    }
    QgsDebugMsgLevel( u"Beautified layer name %1"_s.arg( name() ), 3 );
  }
  else if ( mProviderKey == "osm"_L1 )
  {
    // make sure that the "observer" has been removed from URI to avoid crashes
    mDataSource = mDataProvider->dataSourceUri();
  }
  else if ( provider == "ogr"_L1 )
  {
    // make sure that the /vsigzip or /vsizip is added to uri, if applicable
    mDataSource = mDataProvider->dataSourceUri();
    if ( mDataSource.right( 10 ) == "|layerid=0"_L1 )
      mDataSource.chop( 10 );
  }
  else if ( provider == "memory"_L1 )
  {
    // required so that source differs between memory layers
    mDataSource = mDataSource + u"&uid=%1"_s.arg( QUuid::createUuid().toString() );
  }
  else if ( provider == "hana"_L1 )
  {
    // update datasource from data provider computed one
    mDataSource = mDataProvider->dataSourceUri( false );
  }
 
  connect( mDataProvider, &QgsVectorDataProvider::dataChanged, this, &QgsVectorLayer::emitDataChanged );
  connect( mDataProvider, &QgsVectorDataProvider::dataChanged, this, &QgsVectorLayer::removeSelection );
 
  return true;
} // QgsVectorLayer:: setDataProvider
 
 
/* virtual */
bool QgsVectorLayer::writeXml( QDomNode &layer_node, QDomDocument &document, const QgsReadWriteContext &context ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  // first get the layer element so that we can append the type attribute
 
  QDomElement mapLayerNode = layer_node.toElement();
 
  if ( mapLayerNode.isNull() || ( "maplayer" != mapLayerNode.nodeName() ) )
  {
    QgsDebugMsgLevel( u"can't find <maplayer>"_s, 2 );
    return false;
  }
 
  mapLayerNode.setAttribute( u"type"_s, QgsMapLayerFactory::typeToString( Qgis::LayerType::Vector ) );
 
  // set the geometry type
  mapLayerNode.setAttribute( u"geometry"_s, QgsWkbTypes::geometryDisplayString( geometryType() ) );
  mapLayerNode.setAttribute( u"wkbType"_s, qgsEnumValueToKey( wkbType() ) );
 
  // add provider node
  if ( mDataProvider )
  {
    QDomElement provider = document.createElement( u"provider"_s );
    provider.setAttribute( u"encoding"_s, mDataProvider->encoding() );
    QDomText providerText = document.createTextNode( providerType() );
    provider.appendChild( providerText );
    layer_node.appendChild( provider );
  }
 
  //save joins
  mJoinBuffer->writeXml( layer_node, document );
 
  // dependencies
  QDomElement dependenciesElement = document.createElement( u"layerDependencies"_s );
  const auto constDependencies = dependencies();
  for ( const QgsMapLayerDependency &dep : constDependencies )
  {
    if ( dep.type() != QgsMapLayerDependency::PresenceDependency )
      continue;
    QDomElement depElem = document.createElement( u"layer"_s );
    depElem.setAttribute( u"id"_s, dep.layerId() );
    dependenciesElement.appendChild( depElem );
  }
  layer_node.appendChild( dependenciesElement );
 
  // change dependencies
  QDomElement dataDependenciesElement = document.createElement( u"dataDependencies"_s );
  for ( const QgsMapLayerDependency &dep : constDependencies )
  {
    if ( dep.type() != QgsMapLayerDependency::DataDependency )
      continue;
    QDomElement depElem = document.createElement( u"layer"_s );
    depElem.setAttribute( u"id"_s, dep.layerId() );
    dataDependenciesElement.appendChild( depElem );
  }
  layer_node.appendChild( dataDependenciesElement );
 
  // save expression fields
  mExpressionFieldBuffer->writeXml( layer_node, document );
 
  writeStyleManager( layer_node, document );
 
  // auxiliary layer
  QDomElement asElem = document.createElement( u"auxiliaryLayer"_s );
  if ( mAuxiliaryLayer )
  {
    const QString pkField = mAuxiliaryLayer->joinInfo().targetFieldName();
    asElem.setAttribute( u"key"_s, pkField );
  }
  layer_node.appendChild( asElem );
 
  // renderer specific settings
  QString errorMsg;
  return writeSymbology( layer_node, document, errorMsg, context );
}
 
QString QgsVectorLayer::encodedSource( const QString &source, const QgsReadWriteContext &context ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( providerType() == "memory"_L1 )
  {
    // Refetch the source from the provider, because adding fields actually changes the source for this provider.
    return dataProvider()->dataSourceUri();
  }
 
  return QgsProviderRegistry::instance()->absoluteToRelativeUri( mProviderKey, source, context );
}
 
QString QgsVectorLayer::decodedSource( const QString &source, const QString &provider, const QgsReadWriteContext &context ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return QgsProviderRegistry::instance()->relativeToAbsoluteUri( provider, source, context );
}
 
 
void QgsVectorLayer::resolveReferences( QgsProject *project )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QgsMapLayer::resolveReferences( project );
  mJoinBuffer->resolveReferences( project );
}
 
 
bool QgsVectorLayer::readSymbology( const QDomNode &layerNode, QString &errorMessage, QgsReadWriteContext &context, QgsMapLayer::StyleCategories categories )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( categories.testFlag( Fields ) )
  {
    if ( !mExpressionFieldBuffer )
      mExpressionFieldBuffer = new QgsExpressionFieldBuffer();
    mExpressionFieldBuffer->readXml( layerNode );
 
    updateFields();
  }
 
  if ( categories.testFlag( Relations ) )
  {
    QgsReadWriteContextCategoryPopper p = context.enterCategory( tr( "Relations" ) );
 
    // Restore referenced layers: relations where "this" is the child layer (the referencing part, that holds the FK)
    QDomNodeList referencedLayersNodeList = layerNode.toElement().elementsByTagName( u"referencedLayers"_s );
    if ( referencedLayersNodeList.size() > 0 )
    {
      const QDomNodeList relationNodes { referencedLayersNodeList.at( 0 ).childNodes() };
      for ( int i = 0; i < relationNodes.length(); ++i )
      {
        const QDomElement relationElement = relationNodes.at( i ).toElement();
 
        mWeakRelations.push_back( QgsWeakRelation::readXml( this, QgsWeakRelation::Referencing, relationElement, context.pathResolver() ) );
      }
    }
 
    // Restore referencing layers: relations where "this" is the parent layer (the referenced part where the FK points to)
    QDomNodeList referencingLayersNodeList = layerNode.toElement().elementsByTagName( u"referencingLayers"_s );
    if ( referencingLayersNodeList.size() > 0 )
    {
      const QDomNodeList relationNodes { referencingLayersNodeList.at( 0 ).childNodes() };
      for ( int i = 0; i < relationNodes.length(); ++i )
      {
        const QDomElement relationElement = relationNodes.at( i ).toElement();
        mWeakRelations.push_back( QgsWeakRelation::readXml( this, QgsWeakRelation::Referenced, relationElement, context.pathResolver() ) );
      }
    }
  }
 
  QDomElement layerElement = layerNode.toElement();
 
  readCommonStyle( layerElement, context, categories );
 
  readStyle( layerNode, errorMessage, context, categories );
 
  if ( categories.testFlag( MapTips ) )
  {
    QDomElement mapTipElem = layerNode.namedItem( u"mapTip"_s ).toElement();
    setMapTipTemplate( mapTipElem.text() );
    setMapTipsEnabled( mapTipElem.attribute( u"enabled"_s, u"1"_s ).toInt() == 1 );
  }
 
  if ( categories.testFlag( LayerConfiguration ) )
    mDisplayExpression = layerNode.namedItem( u"previewExpression"_s ).toElement().text();
 
  // Try to migrate pre QGIS 3.0 display field property
  QString displayField = layerNode.namedItem( u"displayfield"_s ).toElement().text();
  if ( mFields.lookupField( displayField ) < 0 )
  {
    // if it's not a field, it's a maptip
    if ( mMapTipTemplate.isEmpty() && categories.testFlag( MapTips ) )
      mMapTipTemplate = displayField;
  }
  else
  {
    if ( mDisplayExpression.isEmpty() && categories.testFlag( LayerConfiguration ) )
      mDisplayExpression = QgsExpression::quotedColumnRef( displayField );
  }
 
  // process the attribute actions
  if ( categories.testFlag( Actions ) )
    mActions->readXml( layerNode, context );
 
  if ( categories.testFlag( Fields ) )
  {
    // IMPORTANT - we don't clear mAttributeAliasMap here, as it may contain aliases which are coming direct
    // from the data provider. Instead we leave any existing aliases and only overwrite them if the style
    // has a specific value for that field's alias
    QDomNode aliasesNode = layerNode.namedItem( u"aliases"_s );
    if ( !aliasesNode.isNull() )
    {
      QDomElement aliasElem;
 
      QDomNodeList aliasNodeList = aliasesNode.toElement().elementsByTagName( u"alias"_s );
      for ( int i = 0; i < aliasNodeList.size(); ++i )
      {
        aliasElem = aliasNodeList.at( i ).toElement();
 
        QString field;
        if ( aliasElem.hasAttribute( u"field"_s ) )
        {
          field = aliasElem.attribute( u"field"_s );
        }
        else
        {
          int index = aliasElem.attribute( u"index"_s ).toInt();
 
          if ( index >= 0 && index < fields().count() )
            field = fields().at( index ).name();
        }
 
        QString alias;
 
        if ( !aliasElem.attribute( u"name"_s ).isEmpty() )
        {
          //if it has alias
          alias = context.projectTranslator()->translate( u"project:layers:%1:fieldaliases"_s.arg( layerNode.namedItem( u"id"_s ).toElement().text() ), aliasElem.attribute( u"name"_s ) );
          QgsDebugMsgLevel( "context" + u"project:layers:%1:fieldaliases"_s.arg( layerNode.namedItem( u"id"_s ).toElement().text() ) + " source " + aliasElem.attribute( u"name"_s ), 3 );
        }
        else
        {
          //if it has no alias, it should be the fields translation
          alias = context.projectTranslator()->translate( u"project:layers:%1:fieldaliases"_s.arg( layerNode.namedItem( u"id"_s ).toElement().text() ), field );
          QgsDebugMsgLevel( "context" + u"project:layers:%1:fieldaliases"_s.arg( layerNode.namedItem( u"id"_s ).toElement().text() ) + " source " + field, 3 );
          //if it gets the exact field value, there has been no translation (or not even translation loaded) - so no alias should be generated;
          if ( alias == aliasElem.attribute( u"field"_s ) )
            alias.clear();
        }
 
        QgsDebugMsgLevel( "field " + field + " origalias " + aliasElem.attribute( u"name"_s ) + " trans " + alias, 3 );
        mAttributeAliasMap.insert( field, alias );
      }
    }
 
    // custom comments
    // mAttributeCustomCommentMap is cleared, because when a custom comment is null the provider comment should be considered
    mAttributeCustomCommentMap.clear();
    QDomNode customCommentsNode = layerNode.namedItem( u"customComments"_s );
    if ( !customCommentsNode.isNull() )
    {
      QDomElement customCommentEntryElem;
 
      QDomNodeList customCommentNodeList = customCommentsNode.toElement().elementsByTagName( u"customComment"_s );
      for ( int i = 0; i < customCommentNodeList.size(); ++i )
      {
        customCommentEntryElem = customCommentNodeList.at( i ).toElement();
 
        const QString field = customCommentEntryElem.attribute( u"field"_s );
 
        //empty values are important as well (to override provider comments with nothing)
        const QString customComment = customCommentEntryElem.attribute( u"value"_s );
 
        if ( fields().lookupField( field ) < 0 )
        {
          QgsDebugMsgLevel( u"Warning: Field %1 not found in layer %2 to load custom comment from setting "_s.arg( field, name() ), 2 );
          continue;
        }
        mAttributeCustomCommentMap.insert( field, customComment );
      }
    }
 
    // IMPORTANT - we don't clear mAttributeSplitPolicy here, as it may contain policies which are coming direct
    // from the data provider. Instead we leave any existing policies and only overwrite them if the style
    // has a specific value for that field's policy
    const QDomNode splitPoliciesNode = layerNode.namedItem( u"splitPolicies"_s );
    if ( !splitPoliciesNode.isNull() )
    {
      const QDomNodeList splitPolicyNodeList = splitPoliciesNode.toElement().elementsByTagName( u"policy"_s );
      for ( int i = 0; i < splitPolicyNodeList.size(); ++i )
      {
        const QDomElement splitPolicyElem = splitPolicyNodeList.at( i ).toElement();
        const QString field = splitPolicyElem.attribute( u"field"_s );
        const Qgis::FieldDomainSplitPolicy policy = qgsEnumKeyToValue( splitPolicyElem.attribute( u"policy"_s ), Qgis::FieldDomainSplitPolicy::Duplicate );
        mAttributeSplitPolicy.insert( field, policy );
      }
    }
 
    // The duplicate policy is - unlike alias and split policy - never defined by the data provider, so we clear the map
    mAttributeDuplicatePolicy.clear();
    const QDomNode duplicatePoliciesNode = layerNode.namedItem( u"duplicatePolicies"_s );
    if ( !duplicatePoliciesNode.isNull() )
    {
      const QDomNodeList duplicatePolicyNodeList = duplicatePoliciesNode.toElement().elementsByTagName( u"policy"_s );
      for ( int i = 0; i < duplicatePolicyNodeList.size(); ++i )
      {
        const QDomElement duplicatePolicyElem = duplicatePolicyNodeList.at( i ).toElement();
        const QString field = duplicatePolicyElem.attribute( u"field"_s );
        const Qgis::FieldDuplicatePolicy policy = qgsEnumKeyToValue( duplicatePolicyElem.attribute( u"policy"_s ), Qgis::FieldDuplicatePolicy::Duplicate );
        mAttributeDuplicatePolicy.insert( field, policy );
      }
    }
 
    const QDomNode mergePoliciesNode = layerNode.namedItem( u"mergePolicies"_s );
    if ( !mergePoliciesNode.isNull() )
    {
      const QDomNodeList mergePolicyNodeList = mergePoliciesNode.toElement().elementsByTagName( u"policy"_s );
      for ( int i = 0; i < mergePolicyNodeList.size(); ++i )
      {
        const QDomElement mergePolicyElem = mergePolicyNodeList.at( i ).toElement();
        const QString field = mergePolicyElem.attribute( u"field"_s );
        const Qgis::FieldDomainMergePolicy policy = qgsEnumKeyToValue( mergePolicyElem.attribute( u"policy"_s ), Qgis::FieldDomainMergePolicy::UnsetField );
        mAttributeMergePolicy.insert( field, policy );
      }
    }
 
    // default expressions
    mDefaultExpressionMap.clear();
    QDomNode defaultsNode = layerNode.namedItem( u"defaults"_s );
    if ( !defaultsNode.isNull() )
    {
      QDomNodeList defaultNodeList = defaultsNode.toElement().elementsByTagName( u"default"_s );
      for ( int i = 0; i < defaultNodeList.size(); ++i )
      {
        QDomElement defaultElem = defaultNodeList.at( i ).toElement();
 
        QString field = defaultElem.attribute( u"field"_s, QString() );
        QString expression = defaultElem.attribute( u"expression"_s, QString() );
        bool applyOnUpdate = defaultElem.attribute( u"applyOnUpdate"_s, u"0"_s ) == "1"_L1;
        if ( field.isEmpty() || expression.isEmpty() )
          continue;
 
        mDefaultExpressionMap.insert( field, QgsDefaultValue( expression, applyOnUpdate ) );
      }
    }
 
    // constraints
    mFieldConstraints.clear();
    mFieldConstraintStrength.clear();
    QDomNode constraintsNode = layerNode.namedItem( u"constraints"_s );
    if ( !constraintsNode.isNull() )
    {
      QDomNodeList constraintNodeList = constraintsNode.toElement().elementsByTagName( u"constraint"_s );
      for ( int i = 0; i < constraintNodeList.size(); ++i )
      {
        QDomElement constraintElem = constraintNodeList.at( i ).toElement();
 
        QString field = constraintElem.attribute( u"field"_s, QString() );
        int constraints = constraintElem.attribute( u"constraints"_s, u"0"_s ).toInt();
        if ( field.isEmpty() || constraints == 0 )
          continue;
 
        mFieldConstraints.insert( field, static_cast< QgsFieldConstraints::Constraints >( constraints ) );
 
        int uniqueStrength = constraintElem.attribute( u"unique_strength"_s, u"1"_s ).toInt();
        int notNullStrength = constraintElem.attribute( u"notnull_strength"_s, u"1"_s ).toInt();
        int expStrength = constraintElem.attribute( u"exp_strength"_s, u"1"_s ).toInt();
 
        mFieldConstraintStrength.insert( qMakePair( field, QgsFieldConstraints::ConstraintUnique ), static_cast< QgsFieldConstraints::ConstraintStrength >( uniqueStrength ) );
        mFieldConstraintStrength.insert( qMakePair( field, QgsFieldConstraints::ConstraintNotNull ), static_cast< QgsFieldConstraints::ConstraintStrength >( notNullStrength ) );
        mFieldConstraintStrength.insert( qMakePair( field, QgsFieldConstraints::ConstraintExpression ), static_cast< QgsFieldConstraints::ConstraintStrength >( expStrength ) );
      }
    }
    mFieldConstraintExpressions.clear();
    QDomNode constraintExpressionsNode = layerNode.namedItem( u"constraintExpressions"_s );
    if ( !constraintExpressionsNode.isNull() )
    {
      QDomNodeList constraintNodeList = constraintExpressionsNode.toElement().elementsByTagName( u"constraint"_s );
      for ( int i = 0; i < constraintNodeList.size(); ++i )
      {
        QDomElement constraintElem = constraintNodeList.at( i ).toElement();
 
        QString field = constraintElem.attribute( u"field"_s, QString() );
        QString exp = constraintElem.attribute( u"exp"_s, QString() );
        QString desc
          = context.projectTranslator()->translate( u"project:layers:%1:constraintdescriptions"_s.arg( layerNode.namedItem( u"id"_s ).toElement().text() ), constraintElem.attribute( u"desc"_s, QString() ) );
        QgsDebugMsgLevel( "context" + u"project:layers:%1:constraintdescriptions"_s.arg( layerNode.namedItem( u"id"_s ).toElement().text() ) + " source " + constraintElem.attribute( u"desc"_s, QString() ), 3 );
        if ( field.isEmpty() || exp.isEmpty() )
          continue;
 
        mFieldConstraintExpressions.insert( field, qMakePair( exp, desc ) );
      }
    }
 
    updateFields();
  }
 
  // load field configuration
  if ( categories.testFlag( Fields ) || categories.testFlag( Forms ) )
  {
    QgsReadWriteContextCategoryPopper p = context.enterCategory( tr( "Forms" ) );
 
    QDomElement widgetsElem = layerNode.namedItem( u"fieldConfiguration"_s ).toElement();
    QDomNodeList fieldConfigurationElementList = widgetsElem.elementsByTagName( u"field"_s );
    for ( int i = 0; i < fieldConfigurationElementList.size(); ++i )
    {
      const QDomElement fieldConfigElement = fieldConfigurationElementList.at( i ).toElement();
      const QDomElement fieldWidgetElement = fieldConfigElement.elementsByTagName( u"editWidget"_s ).at( 0 ).toElement();
 
      QString fieldName = fieldConfigElement.attribute( u"name"_s );
 
      if ( categories.testFlag( Fields ) )
        mFieldConfigurationFlags[fieldName] = qgsFlagKeysToValue( fieldConfigElement.attribute( u"configurationFlags"_s ), Qgis::FieldConfigurationFlag::NoFlag );
 
      // load editor widget configuration
      if ( categories.testFlag( Forms ) )
      {
        const QString widgetType = fieldWidgetElement.attribute( u"type"_s );
        const QDomElement cfgElem = fieldConfigElement.elementsByTagName( u"config"_s ).at( 0 ).toElement();
        const QDomElement optionsElem = cfgElem.childNodes().at( 0 ).toElement();
        QVariantMap optionsMap = QgsXmlUtils::readVariant( optionsElem ).toMap();
        // translate widget configuration strings
        if ( widgetType == "ValueRelation"_L1 )
        {
          optionsMap[u"Value"_s]
            = context.projectTranslator()->translate( u"project:layers:%1:fields:%2:valuerelationvalue"_s.arg( layerNode.namedItem( u"id"_s ).toElement().text(), fieldName ), optionsMap[u"Value"_s].toString() );
          optionsMap[u"Description"_s]
            = context.projectTranslator()
                ->translate( u"project:layers:%1:fields:%2:valuerelationdescription"_s.arg( layerNode.namedItem( u"id"_s ).toElement().text(), fieldName ), optionsMap[u"Description"_s].toString() );
        }
        if ( widgetType == "ValueMap"_L1 )
        {
          if ( optionsMap[u"map"_s].canConvert<QList<QVariant>>() )
          {
            QList<QVariant> translatedValueList;
            const QList<QVariant> valueList = optionsMap[u"map"_s].toList();
            for ( int i = 0, row = 0; i < valueList.count(); i++, row++ )
            {
              QMap<QString, QVariant> translatedValueMap;
              QString translatedKey
                = context.projectTranslator()
                    ->translate( u"project:layers:%1:fields:%2:valuemapdescriptions"_s.arg( layerNode.namedItem( u"id"_s ).toElement().text(), fieldName ), valueList[i].toMap().constBegin().key() );
              translatedValueMap.insert( translatedKey, valueList[i].toMap().constBegin().value() );
              translatedValueList.append( translatedValueMap );
            }
            optionsMap.insert( u"map"_s, translatedValueList );
          }
        }
        QgsEditorWidgetSetup setup = QgsEditorWidgetSetup( widgetType, optionsMap );
        mFieldWidgetSetups[fieldName] = setup;
      }
    }
  }
 
  // Legacy reading for QGIS 3.14 and older projects
  // Attributes excluded from WMS and WFS
  if ( categories.testFlag( Fields ) )
  {
    const QList<QPair<QString, Qgis::FieldConfigurationFlag>>
      legacyConfig { qMakePair( u"excludeAttributesWMS"_s, Qgis::FieldConfigurationFlag::HideFromWms ), qMakePair( u"excludeAttributesWFS"_s, Qgis::FieldConfigurationFlag::HideFromWfs ) };
    for ( const auto &config : legacyConfig )
    {
      QDomNode excludeNode = layerNode.namedItem( config.first );
      if ( !excludeNode.isNull() )
      {
        QDomNodeList attributeNodeList = excludeNode.toElement().elementsByTagName( u"attribute"_s );
        for ( int i = 0; i < attributeNodeList.size(); ++i )
        {
          QString fieldName = attributeNodeList.at( i ).toElement().text();
          if ( !mFieldConfigurationFlags.contains( fieldName ) )
            mFieldConfigurationFlags[fieldName] = config.second;
          else
            mFieldConfigurationFlags[fieldName].setFlag( config.second, true );
        }
      }
    }
  }
 
  if ( categories.testFlag( GeometryOptions ) )
    mGeometryOptions->readXml( layerNode.namedItem( u"geometryOptions"_s ) );
 
  if ( categories.testFlag( Forms ) )
    mEditFormConfig.readXml( layerNode, context );
 
  if ( categories.testFlag( AttributeTable ) )
  {
    mAttributeTableConfig.readXml( layerNode );
    mConditionalStyles->readXml( layerNode, context );
    mStoredExpressionManager->readXml( layerNode );
  }
 
  if ( categories.testFlag( CustomProperties ) )
    readCustomProperties( layerNode, u"variable"_s );
 
  QDomElement mapLayerNode = layerNode.toElement();
  if ( categories.testFlag( LayerConfiguration ) && mapLayerNode.attribute( u"readOnly"_s, u"0"_s ).toInt() == 1 )
    mReadOnly = true;
 
  updateFields();
 
  if ( categories.testFlag( Legend ) )
  {
    QgsReadWriteContextCategoryPopper p = context.enterCategory( tr( "Legend" ) );
 
    const QDomElement legendElem = layerNode.firstChildElement( u"legend"_s );
    if ( !legendElem.isNull() )
    {
      std::unique_ptr< QgsMapLayerLegend > legend( QgsMapLayerLegend::defaultVectorLegend( this ) );
      legend->readXml( legendElem, context );
      setLegend( legend.release() );
      mSetLegendFromStyle = true;
    }
  }
 
  return true;
}
 
bool QgsVectorLayer::readStyle( const QDomNode &node, QString &errorMessage, QgsReadWriteContext &context, QgsMapLayer::StyleCategories categories )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  bool result = true;
  emit readCustomSymbology( node.toElement(), errorMessage );
 
  // we must try to restore a renderer if our geometry type is unknown
  // as this allows the renderer to be correctly restored even for layers
  // with broken sources
  if ( isSpatial() || mWkbType == Qgis::WkbType::Unknown )
  {
    // defer style changed signal until we've set the renderer, labeling, everything.
    // we don't want multiple signals!
    ScopedIntIncrementor styleChangedSignalBlocker( &mBlockStyleChangedSignal );
 
    // try renderer v2 first
    if ( categories.testFlag( Symbology ) )
    {
      QgsReadWriteContextCategoryPopper p = context.enterCategory( tr( "Symbology" ) );
 
      QDomElement rendererElement = node.firstChildElement( RENDERER_TAG_NAME );
      if ( !rendererElement.isNull() )
      {
        QgsFeatureRenderer *r = QgsFeatureRenderer::load( rendererElement, context );
        if ( r )
        {
          setRenderer( r );
        }
        else
        {
          result = false;
        }
      }
      // make sure layer has a renderer - if none exists, fallback to a default renderer
      if ( isSpatial() && !renderer() )
      {
        setRenderer( QgsFeatureRenderer::defaultRenderer( geometryType() ) );
      }
 
      if ( mSelectionProperties )
        mSelectionProperties->readXml( node.toElement(), context );
    }
 
    // read labeling definition
    if ( categories.testFlag( Labeling ) )
    {
      QgsReadWriteContextCategoryPopper p = context.enterCategory( tr( "Labeling" ) );
 
      QDomElement labelingElement = node.firstChildElement( u"labeling"_s );
      QgsAbstractVectorLayerLabeling *labeling = nullptr;
      if ( labelingElement.isNull() || ( labelingElement.attribute( u"type"_s ) == "simple"_L1 && labelingElement.firstChildElement( u"settings"_s ).isNull() ) )
      {
        // make sure we have custom properties for labeling for 2.x projects
        // (custom properties should be already loaded when reading the whole layer from XML,
        // but when reading style, custom properties are not read)
        readCustomProperties( node, u"labeling"_s );
 
        // support for pre-QGIS 3 labeling configurations written in custom properties
        labeling = readLabelingFromCustomProperties();
      }
      else
      {
        labeling = QgsAbstractVectorLayerLabeling::create( labelingElement, context );
      }
      setLabeling( labeling );
 
      if ( node.toElement().hasAttribute( u"labelsEnabled"_s ) )
        mLabelsEnabled = node.toElement().attribute( u"labelsEnabled"_s ).toInt();
      else
        mLabelsEnabled = true;
    }
 
    if ( categories.testFlag( Symbology ) )
    {
      // get and set the blend mode if it exists
      QDomNode blendModeNode = node.namedItem( u"blendMode"_s );
      if ( !blendModeNode.isNull() )
      {
        QDomElement e = blendModeNode.toElement();
        setBlendMode( QgsPainting::getCompositionMode( static_cast< Qgis::BlendMode >( e.text().toInt() ) ) );
      }
 
      // get and set the feature blend mode if it exists
      QDomNode featureBlendModeNode = node.namedItem( u"featureBlendMode"_s );
      if ( !featureBlendModeNode.isNull() )
      {
        QDomElement e = featureBlendModeNode.toElement();
        setFeatureBlendMode( QgsPainting::getCompositionMode( static_cast< Qgis::BlendMode >( e.text().toInt() ) ) );
      }
    }
 
    // get and set the layer transparency and scale visibility if they exists
    if ( categories.testFlag( Rendering ) )
    {
      QDomNode layerTransparencyNode = node.namedItem( u"layerTransparency"_s );
      if ( !layerTransparencyNode.isNull() )
      {
        QDomElement e = layerTransparencyNode.toElement();
        setOpacity( 1.0 - e.text().toInt() / 100.0 );
      }
      QDomNode layerOpacityNode = node.namedItem( u"layerOpacity"_s );
      if ( !layerOpacityNode.isNull() )
      {
        QDomElement e = layerOpacityNode.toElement();
        setOpacity( e.text().toDouble() );
      }
 
      const bool hasScaleBasedVisibiliy { node.attributes().namedItem( u"hasScaleBasedVisibilityFlag"_s ).nodeValue() == '1' };
      setScaleBasedVisibility( hasScaleBasedVisibiliy );
      bool ok;
      const double maxScale { node.attributes().namedItem( u"maxScale"_s ).nodeValue().toDouble( &ok ) };
      if ( ok )
      {
        setMaximumScale( maxScale );
      }
      const double minScale { node.attributes().namedItem( u"minScale"_s ).nodeValue().toDouble( &ok ) };
      if ( ok )
      {
        setMinimumScale( minScale );
      }
 
      QDomElement e = node.toElement();
 
      // get the simplification drawing settings
      mSimplifyMethod.setSimplifyHints( static_cast< Qgis::VectorRenderingSimplificationFlags >( e.attribute( u"simplifyDrawingHints"_s, u"1"_s ).toInt() ) );
      mSimplifyMethod.setSimplifyAlgorithm( static_cast< Qgis::VectorSimplificationAlgorithm >( e.attribute( u"simplifyAlgorithm"_s, u"0"_s ).toInt() ) );
      mSimplifyMethod.setThreshold( e.attribute( u"simplifyDrawingTol"_s, u"1"_s ).toFloat() );
      mSimplifyMethod.setForceLocalOptimization( e.attribute( u"simplifyLocal"_s, u"1"_s ).toInt() );
      mSimplifyMethod.setMaximumScale( e.attribute( u"simplifyMaxScale"_s, u"1"_s ).toFloat() );
 
      if ( mRenderer )
        mRenderer->setReferenceScale( e.attribute( u"symbologyReferenceScale"_s, u"-1"_s ).toDouble() );
    }
 
    //diagram renderer and diagram layer settings
    if ( categories.testFlag( Diagrams ) )
    {
      QgsReadWriteContextCategoryPopper p = context.enterCategory( tr( "Diagrams" ) );
 
      delete mDiagramRenderer;
      mDiagramRenderer = nullptr;
      QDomElement singleCatDiagramElem = node.firstChildElement( u"SingleCategoryDiagramRenderer"_s );
      if ( !singleCatDiagramElem.isNull() )
      {
        mDiagramRenderer = new QgsSingleCategoryDiagramRenderer();
        mDiagramRenderer->readXml( singleCatDiagramElem, context );
      }
      QDomElement linearDiagramElem = node.firstChildElement( u"LinearlyInterpolatedDiagramRenderer"_s );
      if ( !linearDiagramElem.isNull() )
      {
        if ( linearDiagramElem.hasAttribute( u"classificationAttribute"_s ) )
        {
          // fix project from before QGIS 3.0
          int idx = linearDiagramElem.attribute( u"classificationAttribute"_s ).toInt();
          if ( idx >= 0 && idx < mFields.count() )
            linearDiagramElem.setAttribute( u"classificationField"_s, mFields.at( idx ).name() );
        }
 
        mDiagramRenderer = new QgsLinearlyInterpolatedDiagramRenderer();
        mDiagramRenderer->readXml( linearDiagramElem, context );
      }
      QDomElement stackedDiagramElem = node.firstChildElement( u"StackedDiagramRenderer"_s );
      if ( !stackedDiagramElem.isNull() )
      {
        mDiagramRenderer = new QgsStackedDiagramRenderer();
        mDiagramRenderer->readXml( stackedDiagramElem, context );
      }
 
      if ( mDiagramRenderer )
      {
        QDomElement diagramSettingsElem = node.firstChildElement( u"DiagramLayerSettings"_s );
        if ( !diagramSettingsElem.isNull() )
        {
          bool oldXPos = diagramSettingsElem.hasAttribute( u"xPosColumn"_s );
          bool oldYPos = diagramSettingsElem.hasAttribute( u"yPosColumn"_s );
          bool oldShow = diagramSettingsElem.hasAttribute( u"showColumn"_s );
          if ( oldXPos || oldYPos || oldShow )
          {
            // fix project from before QGIS 3.0
            QgsPropertyCollection ddp;
            if ( oldXPos )
            {
              int xPosColumn = diagramSettingsElem.attribute( u"xPosColumn"_s ).toInt();
              if ( xPosColumn >= 0 && xPosColumn < mFields.count() )
                ddp.setProperty( QgsDiagramLayerSettings::Property::PositionX, QgsProperty::fromField( mFields.at( xPosColumn ).name(), true ) );
            }
            if ( oldYPos )
            {
              int yPosColumn = diagramSettingsElem.attribute( u"yPosColumn"_s ).toInt();
              if ( yPosColumn >= 0 && yPosColumn < mFields.count() )
                ddp.setProperty( QgsDiagramLayerSettings::Property::PositionY, QgsProperty::fromField( mFields.at( yPosColumn ).name(), true ) );
            }
            if ( oldShow )
            {
              int showColumn = diagramSettingsElem.attribute( u"showColumn"_s ).toInt();
              if ( showColumn >= 0 && showColumn < mFields.count() )
                ddp.setProperty( QgsDiagramLayerSettings::Property::Show, QgsProperty::fromField( mFields.at( showColumn ).name(), true ) );
            }
            QDomElement propertiesElem = diagramSettingsElem.ownerDocument().createElement( u"properties"_s );
            QgsPropertiesDefinition defs = QgsPropertiesDefinition {
              { static_cast< int >( QgsDiagramLayerSettings::Property::PositionX ), QgsPropertyDefinition( "positionX", QObject::tr( "Position (X)" ), QgsPropertyDefinition::Double ) },
              { static_cast< int >( QgsDiagramLayerSettings::Property::PositionY ), QgsPropertyDefinition( "positionY", QObject::tr( "Position (Y)" ), QgsPropertyDefinition::Double ) },
              { static_cast< int >( QgsDiagramLayerSettings::Property::Show ), QgsPropertyDefinition( "show", QObject::tr( "Show diagram" ), QgsPropertyDefinition::Boolean ) },
            };
            ddp.writeXml( propertiesElem, defs );
            diagramSettingsElem.appendChild( propertiesElem );
          }
 
          delete mDiagramLayerSettings;
          mDiagramLayerSettings = new QgsDiagramLayerSettings();
          mDiagramLayerSettings->readXml( diagramSettingsElem );
        }
      }
    }
    // end diagram
 
    styleChangedSignalBlocker.release();
    emitStyleChanged();
  }
  return result;
}
 
 
bool QgsVectorLayer::writeSymbology( QDomNode &node, QDomDocument &doc, QString &errorMessage, const QgsReadWriteContext &context, QgsMapLayer::StyleCategories categories ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QDomElement layerElement = node.toElement();
  writeCommonStyle( layerElement, doc, context, categories );
 
  ( void ) writeStyle( node, doc, errorMessage, context, categories );
 
  if ( categories.testFlag( GeometryOptions ) )
    mGeometryOptions->writeXml( node );
 
  if ( categories.testFlag( Legend ) && legend() )
  {
    QDomElement legendElement = legend()->writeXml( doc, context );
    if ( !legendElement.isNull() )
      node.appendChild( legendElement );
  }
 
  // Relation information for both referenced and referencing sides
  if ( categories.testFlag( Relations ) )
  {
    if ( QgsProject *p = project() )
    {
      // Store referenced layers: relations where "this" is the child layer (the referencing part, that holds the FK)
      QDomElement referencedLayersElement = doc.createElement( u"referencedLayers"_s );
      node.appendChild( referencedLayersElement );
 
      const QList<QgsRelation> referencingRelations { p->relationManager()->referencingRelations( this ) };
      for ( const QgsRelation &rel : referencingRelations )
      {
        switch ( rel.type() )
        {
          case Qgis::RelationshipType::Normal:
            QgsWeakRelation::writeXml( this, QgsWeakRelation::Referencing, rel, referencedLayersElement, doc );
            break;
          case Qgis::RelationshipType::Generated:
            break;
        }
      }
 
      // Store referencing layers: relations where "this" is the parent layer (the referenced part, that holds the FK)
      QDomElement referencingLayersElement = doc.createElement( u"referencingLayers"_s );
      node.appendChild( referencingLayersElement );
 
      const QList<QgsRelation> referencedRelations { p->relationManager()->referencedRelations( this ) };
      for ( const QgsRelation &rel : referencedRelations )
      {
        switch ( rel.type() )
        {
          case Qgis::RelationshipType::Normal:
            QgsWeakRelation::writeXml( this, QgsWeakRelation::Referenced, rel, referencingLayersElement, doc );
            break;
          case Qgis::RelationshipType::Generated:
            break;
        }
      }
    }
  }
 
  // write field configurations
  if ( categories.testFlag( Fields ) || categories.testFlag( Forms ) )
  {
    QDomElement fieldConfigurationElement;
    // field configuration flag
    fieldConfigurationElement = doc.createElement( u"fieldConfiguration"_s );
    node.appendChild( fieldConfigurationElement );
 
    for ( const QgsField &field : std::as_const( mFields ) )
    {
      QDomElement fieldElement = doc.createElement( u"field"_s );
      fieldElement.setAttribute( u"name"_s, field.name() );
      fieldConfigurationElement.appendChild( fieldElement );
 
      if ( categories.testFlag( Fields ) )
      {
        fieldElement.setAttribute( u"configurationFlags"_s, qgsFlagValueToKeys( field.configurationFlags() ) );
      }
 
      if ( categories.testFlag( Forms ) )
      {
        QgsEditorWidgetSetup widgetSetup = field.editorWidgetSetup();
 
        // TODO : wrap this part in an if to only save if it was user-modified
        QDomElement editWidgetElement = doc.createElement( u"editWidget"_s );
        fieldElement.appendChild( editWidgetElement );
        editWidgetElement.setAttribute( u"type"_s, field.editorWidgetSetup().type() );
        QDomElement editWidgetConfigElement = doc.createElement( u"config"_s );
 
        editWidgetConfigElement.appendChild( QgsXmlUtils::writeVariant( widgetSetup.config(), doc ) );
        editWidgetElement.appendChild( editWidgetConfigElement );
        // END TODO : wrap this part in an if to only save if it was user-modified
      }
    }
  }
 
  if ( categories.testFlag( Fields ) )
  {
    //attribute aliases
    QDomElement aliasElem = doc.createElement( u"aliases"_s );
    for ( const QgsField &field : std::as_const( mFields ) )
    {
      QDomElement aliasEntryElem = doc.createElement( u"alias"_s );
      aliasEntryElem.setAttribute( u"field"_s, field.name() );
      aliasEntryElem.setAttribute( u"index"_s, mFields.indexFromName( field.name() ) );
      aliasEntryElem.setAttribute( u"name"_s, field.alias() );
      aliasElem.appendChild( aliasEntryElem );
    }
    node.appendChild( aliasElem );
 
    //custom comments
    QDomElement customCommentElem = doc.createElement( u"customComments"_s );
    for ( const QgsField &field : std::as_const( mFields ) )
    {
      //if empty ("") we store it, if null we don't store it
      const QString customComment = field.customComment();
      if ( customComment.isNull() )
        continue;
 
      QDomElement customCommentEntryElem = doc.createElement( u"customComment"_s );
      customCommentEntryElem.setAttribute( u"field"_s, field.name() );
      customCommentEntryElem.setAttribute( u"value"_s, customComment );
      customCommentElem.appendChild( customCommentEntryElem );
    }
    node.appendChild( customCommentElem );
 
    //split policies
    {
      QDomElement splitPoliciesElement = doc.createElement( u"splitPolicies"_s );
      bool hasNonDefaultSplitPolicies = false;
      for ( const QgsField &field : std::as_const( mFields ) )
      {
        if ( field.splitPolicy() != Qgis::FieldDomainSplitPolicy::Duplicate )
        {
          QDomElement splitPolicyElem = doc.createElement( u"policy"_s );
          splitPolicyElem.setAttribute( u"field"_s, field.name() );
          splitPolicyElem.setAttribute( u"policy"_s, qgsEnumValueToKey( field.splitPolicy() ) );
          splitPoliciesElement.appendChild( splitPolicyElem );
          hasNonDefaultSplitPolicies = true;
        }
      }
      if ( hasNonDefaultSplitPolicies )
        node.appendChild( splitPoliciesElement );
    }
 
    //duplicate policies
    {
      QDomElement duplicatePoliciesElement = doc.createElement( u"duplicatePolicies"_s );
      bool hasNonDefaultDuplicatePolicies = false;
      for ( const QgsField &field : std::as_const( mFields ) )
      {
        if ( field.duplicatePolicy() != Qgis::FieldDuplicatePolicy::Duplicate )
        {
          QDomElement duplicatePolicyElem = doc.createElement( u"policy"_s );
          duplicatePolicyElem.setAttribute( u"field"_s, field.name() );
          duplicatePolicyElem.setAttribute( u"policy"_s, qgsEnumValueToKey( field.duplicatePolicy() ) );
          duplicatePoliciesElement.appendChild( duplicatePolicyElem );
          hasNonDefaultDuplicatePolicies = true;
        }
      }
      if ( hasNonDefaultDuplicatePolicies )
        node.appendChild( duplicatePoliciesElement );
    }
 
    //merge policies
    {
      QDomElement mergePoliciesElement = doc.createElement( u"mergePolicies"_s );
      bool hasNonDefaultMergePolicies = false;
      for ( const QgsField &field : std::as_const( mFields ) )
      {
        if ( field.mergePolicy() != Qgis::FieldDomainMergePolicy::UnsetField )
        {
          QDomElement mergePolicyElem = doc.createElement( u"policy"_s );
          mergePolicyElem.setAttribute( u"field"_s, field.name() );
          mergePolicyElem.setAttribute( u"policy"_s, qgsEnumValueToKey( field.mergePolicy() ) );
          mergePoliciesElement.appendChild( mergePolicyElem );
          hasNonDefaultMergePolicies = true;
        }
      }
      if ( hasNonDefaultMergePolicies )
        node.appendChild( mergePoliciesElement );
    }
 
    //default expressions
    QDomElement defaultsElem = doc.createElement( u"defaults"_s );
    for ( const QgsField &field : std::as_const( mFields ) )
    {
      QDomElement defaultElem = doc.createElement( u"default"_s );
      defaultElem.setAttribute( u"field"_s, field.name() );
      defaultElem.setAttribute( u"expression"_s, field.defaultValueDefinition().expression() );
      defaultElem.setAttribute( u"applyOnUpdate"_s, field.defaultValueDefinition().applyOnUpdate() ? u"1"_s : u"0"_s );
      defaultsElem.appendChild( defaultElem );
    }
    node.appendChild( defaultsElem );
 
    // constraints
    QDomElement constraintsElem = doc.createElement( u"constraints"_s );
    for ( const QgsField &field : std::as_const( mFields ) )
    {
      QDomElement constraintElem = doc.createElement( u"constraint"_s );
      constraintElem.setAttribute( u"field"_s, field.name() );
      constraintElem.setAttribute( u"constraints"_s, field.constraints().constraints() );
      constraintElem.setAttribute( u"unique_strength"_s, field.constraints().constraintStrength( QgsFieldConstraints::ConstraintUnique ) );
      constraintElem.setAttribute( u"notnull_strength"_s, field.constraints().constraintStrength( QgsFieldConstraints::ConstraintNotNull ) );
      constraintElem.setAttribute( u"exp_strength"_s, field.constraints().constraintStrength( QgsFieldConstraints::ConstraintExpression ) );
 
      constraintsElem.appendChild( constraintElem );
    }
    node.appendChild( constraintsElem );
 
    // constraint expressions
    QDomElement constraintExpressionsElem = doc.createElement( u"constraintExpressions"_s );
    for ( const QgsField &field : std::as_const( mFields ) )
    {
      QDomElement constraintExpressionElem = doc.createElement( u"constraint"_s );
      constraintExpressionElem.setAttribute( u"field"_s, field.name() );
      constraintExpressionElem.setAttribute( u"exp"_s, field.constraints().constraintExpression() );
      constraintExpressionElem.setAttribute( u"desc"_s, field.constraints().constraintDescription() );
      constraintExpressionsElem.appendChild( constraintExpressionElem );
    }
    node.appendChild( constraintExpressionsElem );
 
    // save expression fields
    if ( !mExpressionFieldBuffer )
    {
      // can happen when saving style on a invalid layer
      QgsExpressionFieldBuffer dummy;
      dummy.writeXml( node, doc );
    }
    else
    {
      mExpressionFieldBuffer->writeXml( node, doc );
    }
  }
 
  // add attribute actions
  if ( categories.testFlag( Actions ) )
    mActions->writeXml( node );
 
  if ( categories.testFlag( AttributeTable ) )
  {
    mAttributeTableConfig.writeXml( node );
    mConditionalStyles->writeXml( node, doc, context );
    mStoredExpressionManager->writeXml( node );
  }
 
  if ( categories.testFlag( Forms ) )
    mEditFormConfig.writeXml( node, context );
 
  // save readonly state
  if ( categories.testFlag( LayerConfiguration ) )
    node.toElement().setAttribute( u"readOnly"_s, mReadOnly );
 
  // save preview expression
  if ( categories.testFlag( LayerConfiguration ) )
  {
    QDomElement prevExpElem = doc.createElement( u"previewExpression"_s );
    QDomText prevExpText = doc.createTextNode( mDisplayExpression );
    prevExpElem.appendChild( prevExpText );
    node.appendChild( prevExpElem );
  }
 
  // save map tip
  if ( categories.testFlag( MapTips ) )
  {
    QDomElement mapTipElem = doc.createElement( u"mapTip"_s );
    mapTipElem.setAttribute( u"enabled"_s, mapTipsEnabled() );
    QDomText mapTipText = doc.createTextNode( mMapTipTemplate );
    mapTipElem.appendChild( mapTipText );
    node.toElement().appendChild( mapTipElem );
  }
 
  return true;
}
 
bool QgsVectorLayer::writeStyle( QDomNode &node, QDomDocument &doc, QString &errorMessage, const QgsReadWriteContext &context, QgsMapLayer::StyleCategories categories ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QDomElement mapLayerNode = node.toElement();
 
  emit writeCustomSymbology( mapLayerNode, doc, errorMessage );
 
  // we must try to write the renderer if our geometry type is unknown
  // as this allows the renderer to be correctly restored even for layers
  // with broken sources
  if ( isSpatial() || mWkbType == Qgis::WkbType::Unknown )
  {
    if ( categories.testFlag( Symbology ) )
    {
      if ( mRenderer )
      {
        QDomElement rendererElement = mRenderer->save( doc, context );
        node.appendChild( rendererElement );
      }
      if ( mSelectionProperties )
      {
        mSelectionProperties->writeXml( mapLayerNode, doc, context );
      }
    }
 
    if ( categories.testFlag( Labeling ) )
    {
      if ( mLabeling )
      {
        QDomElement labelingElement = mLabeling->save( doc, context );
        node.appendChild( labelingElement );
      }
      mapLayerNode.setAttribute( u"labelsEnabled"_s, mLabelsEnabled ? u"1"_s : u"0"_s );
    }
 
    // save the simplification drawing settings
    if ( categories.testFlag( Rendering ) )
    {
      mapLayerNode.setAttribute( u"simplifyDrawingHints"_s, QString::number( static_cast< int >( mSimplifyMethod.simplifyHints() ) ) );
      mapLayerNode.setAttribute( u"simplifyAlgorithm"_s, QString::number( static_cast< int >( mSimplifyMethod.simplifyAlgorithm() ) ) );
      mapLayerNode.setAttribute( u"simplifyDrawingTol"_s, QString::number( mSimplifyMethod.threshold() ) );
      mapLayerNode.setAttribute( u"simplifyLocal"_s, mSimplifyMethod.forceLocalOptimization() ? 1 : 0 );
      mapLayerNode.setAttribute( u"simplifyMaxScale"_s, QString::number( mSimplifyMethod.maximumScale() ) );
    }
 
    //save customproperties
    if ( categories.testFlag( CustomProperties ) )
    {
      writeCustomProperties( node, doc );
    }
 
    if ( categories.testFlag( Symbology ) )
    {
      // add the blend mode field
      QDomElement blendModeElem = doc.createElement( u"blendMode"_s );
      QDomText blendModeText = doc.createTextNode( QString::number( static_cast< int >( QgsPainting::getBlendModeEnum( blendMode() ) ) ) );
      blendModeElem.appendChild( blendModeText );
      node.appendChild( blendModeElem );
 
      // add the feature blend mode field
      QDomElement featureBlendModeElem = doc.createElement( u"featureBlendMode"_s );
      QDomText featureBlendModeText = doc.createTextNode( QString::number( static_cast< int >( QgsPainting::getBlendModeEnum( featureBlendMode() ) ) ) );
      featureBlendModeElem.appendChild( featureBlendModeText );
      node.appendChild( featureBlendModeElem );
    }
 
    // add the layer opacity and scale visibility
    if ( categories.testFlag( Rendering ) )
    {
      QDomElement layerOpacityElem = doc.createElement( u"layerOpacity"_s );
      QDomText layerOpacityText = doc.createTextNode( QString::number( opacity() ) );
      layerOpacityElem.appendChild( layerOpacityText );
      node.appendChild( layerOpacityElem );
      mapLayerNode.setAttribute( u"hasScaleBasedVisibilityFlag"_s, hasScaleBasedVisibility() ? 1 : 0 );
      mapLayerNode.setAttribute( u"maxScale"_s, maximumScale() );
      mapLayerNode.setAttribute( u"minScale"_s, minimumScale() );
 
      mapLayerNode.setAttribute( u"symbologyReferenceScale"_s, mRenderer ? mRenderer->referenceScale() : -1 );
    }
 
    if ( categories.testFlag( Diagrams ) && mDiagramRenderer )
    {
      mDiagramRenderer->writeXml( mapLayerNode, doc, context );
      if ( mDiagramLayerSettings )
        mDiagramLayerSettings->writeXml( mapLayerNode, doc );
    }
  }
  return true;
}
 
bool QgsVectorLayer::readSld( const QDomNode &node, QString &errorMessage )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  // get the Name element
  QDomElement nameElem = node.firstChildElement( u"Name"_s );
  if ( nameElem.isNull() )
  {
    errorMessage = u"Warning: Name element not found within NamedLayer while it's required."_s;
  }
 
  if ( isSpatial() )
  {
    QgsFeatureRenderer *r = QgsFeatureRenderer::loadSld( node, geometryType(), errorMessage );
    if ( !r )
      return false;
 
    // defer style changed signal until we've set the renderer, labeling, everything.
    // we don't want multiple signals!
    ScopedIntIncrementor styleChangedSignalBlocker( &mBlockStyleChangedSignal );
 
    setRenderer( r );
 
    // labeling
    readSldLabeling( node );
 
    styleChangedSignalBlocker.release();
    emitStyleChanged();
  }
  return true;
}
 
bool QgsVectorLayer::writeSld( QDomNode &node, QDomDocument &doc, QString &, const QVariantMap &props ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
  QgsSldExportContext context;
  context.setExtraProperties( props );
  writeSld( node, doc, context );
  return true;
}
 
bool QgsVectorLayer::writeSld( QDomNode &node, QDomDocument &doc, QgsSldExportContext &context ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QVariantMap localProps = context.extraProperties();
  if ( hasScaleBasedVisibility() )
  {
    QgsSymbolLayerUtils::mergeScaleDependencies( maximumScale(), minimumScale(), localProps );
  }
  context.setExtraProperties( localProps );
 
  if ( isSpatial() )
  {
    // store the Name element
    QDomElement nameNode = doc.createElement( u"se:Name"_s );
    nameNode.appendChild( doc.createTextNode( name() ) );
    node.appendChild( nameNode );
 
    QDomElement userStyleElem = doc.createElement( u"UserStyle"_s );
    node.appendChild( userStyleElem );
 
    QDomElement nameElem = doc.createElement( u"se:Name"_s );
    nameElem.appendChild( doc.createTextNode( name() ) );
 
    userStyleElem.appendChild( nameElem );
 
    QDomElement featureTypeStyleElem = doc.createElement( u"se:FeatureTypeStyle"_s );
    userStyleElem.appendChild( featureTypeStyleElem );
 
    mRenderer->toSld( doc, featureTypeStyleElem, context );
    if ( labelsEnabled() )
    {
      mLabeling->toSld( featureTypeStyleElem, context );
    }
  }
  return true;
}
 
bool QgsVectorLayer::changeGeometry( QgsFeatureId fid, QgsGeometry &geom, bool skipDefaultValue )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !mEditBuffer || !mDataProvider )
  {
    return false;
  }
 
  if ( mGeometryOptions->isActive() )
    mGeometryOptions->apply( geom );
 
  updateExtents();
 
  bool result = mEditBuffer->changeGeometry( fid, geom );
 
  if ( result )
  {
    updateExtents();
    if ( !skipDefaultValue && !mDefaultValueOnUpdateFields.isEmpty() )
      updateDefaultValues( fid );
  }
  return result;
}
 
 
bool QgsVectorLayer::changeAttributeValue( QgsFeatureId fid, int field, const QVariant &newValue, const QVariant &oldValue, bool skipDefaultValues, QgsVectorLayerToolsContext *context )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  bool result = false;
 
  switch ( fields().fieldOrigin( field ) )
  {
    case Qgis::FieldOrigin::Join:
      result = mJoinBuffer->changeAttributeValue( fid, field, newValue, oldValue );
      if ( result )
        emit attributeValueChanged( fid, field, newValue );
      break;
 
    case Qgis::FieldOrigin::Provider:
    case Qgis::FieldOrigin::Edit:
    case Qgis::FieldOrigin::Expression:
    {
      if ( mEditBuffer && mDataProvider )
        result = mEditBuffer->changeAttributeValue( fid, field, newValue, oldValue );
      break;
    }
 
    case Qgis::FieldOrigin::Unknown:
      break;
  }
 
  if ( result && !skipDefaultValues && !mDefaultValueOnUpdateFields.isEmpty() )
    updateDefaultValues( fid, QgsFeature(), context ? context->expressionContext() : nullptr );
 
  return result;
}
 
bool QgsVectorLayer::changeAttributeValues( QgsFeatureId fid, const QgsAttributeMap &newValues, const QgsAttributeMap &oldValues, bool skipDefaultValues, QgsVectorLayerToolsContext *context )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  bool result = true;
 
  QgsAttributeMap newValuesJoin;
  QgsAttributeMap oldValuesJoin;
 
  QgsAttributeMap newValuesNotJoin;
  QgsAttributeMap oldValuesNotJoin;
 
  for ( auto it = newValues.constBegin(); it != newValues.constEnd(); ++it )
  {
    const int field = it.key();
    const QVariant newValue = it.value();
    QVariant oldValue;
 
    if ( oldValues.contains( field ) )
      oldValue = oldValues[field];
 
    switch ( fields().fieldOrigin( field ) )
    {
      case Qgis::FieldOrigin::Join:
        newValuesJoin[field] = newValue;
        oldValuesJoin[field] = oldValue;
        break;
 
      case Qgis::FieldOrigin::Provider:
      case Qgis::FieldOrigin::Edit:
      case Qgis::FieldOrigin::Expression:
      {
        newValuesNotJoin[field] = newValue;
        oldValuesNotJoin[field] = oldValue;
        break;
      }
 
      case Qgis::FieldOrigin::Unknown:
        break;
    }
  }
 
  if ( !newValuesJoin.isEmpty() && mJoinBuffer )
  {
    result = mJoinBuffer->changeAttributeValues( fid, newValuesJoin, oldValuesJoin );
  }
 
  if ( !newValuesNotJoin.isEmpty() )
  {
    if ( mEditBuffer && mDataProvider )
      result &= mEditBuffer->changeAttributeValues( fid, newValuesNotJoin, oldValues );
    else
      result = false;
  }
 
  if ( result && !skipDefaultValues && !mDefaultValueOnUpdateFields.isEmpty() )
  {
    updateDefaultValues( fid, QgsFeature(), context ? context->expressionContext() : nullptr );
  }
 
  return result;
}
 
bool QgsVectorLayer::addAttribute( const QgsField &field )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !mEditBuffer || !mDataProvider )
    return false;
 
  return mEditBuffer->addAttribute( field );
}
 
void QgsVectorLayer::removeFieldAlias( int attIndex )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( attIndex < 0 || attIndex >= fields().count() )
    return;
 
  QString name = fields().at( attIndex ).name();
  mFields[attIndex].setAlias( QString() );
  if ( mAttributeAliasMap.contains( name ) )
  {
    mAttributeAliasMap.remove( name );
    updateFields();
    mEditFormConfig.setFields( mFields );
    emit layerModified();
  }
}
 
bool QgsVectorLayer::renameAttribute( int index, const QString &newName )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( index < 0 || index >= fields().count() )
    return false;
 
  switch ( mFields.fieldOrigin( index ) )
  {
    case Qgis::FieldOrigin::Expression:
    {
      if ( mExpressionFieldBuffer )
      {
        int oi = mFields.fieldOriginIndex( index );
        mExpressionFieldBuffer->renameExpression( oi, newName );
        updateFields();
        return true;
      }
      else
      {
        return false;
      }
    }
 
    case Qgis::FieldOrigin::Provider:
    case Qgis::FieldOrigin::Edit:
 
      if ( !mEditBuffer || !mDataProvider )
        return false;
 
      return mEditBuffer->renameAttribute( index, newName );
 
    case Qgis::FieldOrigin::Join:
    case Qgis::FieldOrigin::Unknown:
      return false;
  }
 
  return false; // avoid warning
}
 
void QgsVectorLayer::setFieldAlias( int attIndex, const QString &aliasString )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( attIndex < 0 || attIndex >= fields().count() )
    return;
 
  QString name = fields().at( attIndex ).name();
 
  mAttributeAliasMap.insert( name, aliasString );
  mFields[attIndex].setAlias( aliasString );
  mEditFormConfig.setFields( mFields );
  emit layerModified(); // TODO[MD]: should have a different signal?
}
 
QString QgsVectorLayer::attributeAlias( int index ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( index < 0 || index >= fields().count() )
    return QString();
 
  return fields().at( index ).alias();
}
 
void QgsVectorLayer::setFieldCustomComment( int attIndex, const QString &customCommentString )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( attIndex < 0 || attIndex >= fields().count() )
    return;
 
  QString name = fields().at( attIndex ).name();
 
  mAttributeCustomCommentMap.insert( name, customCommentString );
  mFields[attIndex].setCustomComment( customCommentString );
  mEditFormConfig.setFields( mFields );
  emit layerModified();
}
 
void QgsVectorLayer::removeFieldCustomComment( int attIndex )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( attIndex < 0 || attIndex >= fields().count() )
    return;
 
  QString name = fields().at( attIndex ).name();
  mFields[attIndex].setCustomComment( QString() );
  if ( mAttributeCustomCommentMap.contains( name ) )
  {
    mAttributeCustomCommentMap.remove( name );
    updateFields();
    mEditFormConfig.setFields( mFields );
    emit layerModified();
  }
}
 
QString QgsVectorLayer::attributeCustomComment( int index ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( index < 0 || index >= fields().count() )
    return QString();
 
  return fields().at( index ).customComment();
}
 
QgsStringMap QgsVectorLayer::attributeCustomComments() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return mAttributeCustomCommentMap;
}
 
QString QgsVectorLayer::attributeDisplayName( int index ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( index >= 0 && index < mFields.count() )
    return mFields.at( index ).displayName();
  else
    return QString();
}
 
QgsStringMap QgsVectorLayer::attributeAliases() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return mAttributeAliasMap;
}
 
void QgsVectorLayer::setFieldSplitPolicy( int index, Qgis::FieldDomainSplitPolicy policy )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( index < 0 || index >= fields().count() )
    return;
 
  const QString name = fields().at( index ).name();
 
  mAttributeSplitPolicy.insert( name, policy );
  mFields[index].setSplitPolicy( policy );
  mEditFormConfig.setFields( mFields );
  emit layerModified(); // TODO[MD]: should have a different signal?
}
 
void QgsVectorLayer::setFieldDuplicatePolicy( int index, Qgis::FieldDuplicatePolicy policy )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( index < 0 || index >= fields().count() )
    return;
 
  const QString name = fields().at( index ).name();
 
  mAttributeDuplicatePolicy.insert( name, policy );
  mFields[index].setDuplicatePolicy( policy );
  mEditFormConfig.setFields( mFields );
  emit layerModified(); // TODO[MD]: should have a different signal?
}
 
void QgsVectorLayer::setFieldMergePolicy( int index, Qgis::FieldDomainMergePolicy policy )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( index < 0 || index >= fields().count() )
    return;
 
  const QString name = fields().at( index ).name();
 
  mAttributeMergePolicy.insert( name, policy );
  mFields[index].setMergePolicy( policy );
  mEditFormConfig.setFields( mFields );
  emit layerModified(); // TODO[MD]: should have a different signal?
}
 
QSet<QString> QgsVectorLayer::excludeAttributesWms() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QSet<QString> excludeList;
  QMap< QString, Qgis::FieldConfigurationFlags >::const_iterator flagsIt = mFieldConfigurationFlags.constBegin();
  for ( ; flagsIt != mFieldConfigurationFlags.constEnd(); ++flagsIt )
  {
    if ( flagsIt->testFlag( Qgis::FieldConfigurationFlag::HideFromWms ) )
    {
      excludeList << flagsIt.key();
    }
  }
  return excludeList;
}
 
void QgsVectorLayer::setExcludeAttributesWms( const QSet<QString> &att )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QMap< QString, Qgis::FieldConfigurationFlags >::iterator flagsIt = mFieldConfigurationFlags.begin();
  for ( ; flagsIt != mFieldConfigurationFlags.end(); ++flagsIt )
  {
    flagsIt->setFlag( Qgis::FieldConfigurationFlag::HideFromWms, att.contains( flagsIt.key() ) );
  }
  updateFields();
}
 
QSet<QString> QgsVectorLayer::excludeAttributesWfs() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QSet<QString> excludeList;
  QMap< QString, Qgis::FieldConfigurationFlags >::const_iterator flagsIt = mFieldConfigurationFlags.constBegin();
  for ( ; flagsIt != mFieldConfigurationFlags.constEnd(); ++flagsIt )
  {
    if ( flagsIt->testFlag( Qgis::FieldConfigurationFlag::HideFromWfs ) )
    {
      excludeList << flagsIt.key();
    }
  }
  return excludeList;
}
 
void QgsVectorLayer::setExcludeAttributesWfs( const QSet<QString> &att )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QMap< QString, Qgis::FieldConfigurationFlags >::iterator flagsIt = mFieldConfigurationFlags.begin();
  for ( ; flagsIt != mFieldConfigurationFlags.end(); ++flagsIt )
  {
    flagsIt->setFlag( Qgis::FieldConfigurationFlag::HideFromWfs, att.contains( flagsIt.key() ) );
  }
  updateFields();
}
 
bool QgsVectorLayer::deleteAttribute( int index )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( index < 0 || index >= fields().count() )
    return false;
 
  if ( mFields.fieldOrigin( index ) == Qgis::FieldOrigin::Expression )
  {
    removeExpressionField( index );
    return true;
  }
 
  if ( !mEditBuffer || !mDataProvider )
    return false;
 
  return mEditBuffer->deleteAttribute( index );
}
 
bool QgsVectorLayer::deleteAttributes( const QList<int> &attrs )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  bool deleted = false;
 
  // Remove multiple occurrences of same attribute
  QList<int> attrList = qgis::setToList( qgis::listToSet( attrs ) );
 
  std::sort( attrList.begin(), attrList.end(), std::greater<int>() );
 
  for ( int attr : std::as_const( attrList ) )
  {
    if ( deleteAttribute( attr ) )
    {
      deleted = true;
    }
  }
 
  return deleted;
}
 
bool QgsVectorLayer::deleteFeatureCascade( QgsFeatureId fid, QgsVectorLayer::DeleteContext *context )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !mEditBuffer )
    return false;
 
  if ( context && context->cascade )
  {
    const QList<QgsRelation> relations = context->project->relationManager()->referencedRelations( this );
    const bool hasRelationsOrJoins = !relations.empty() || mJoinBuffer->containsJoins();
    if ( hasRelationsOrJoins )
    {
      if ( context->mHandledFeatures.contains( this ) )
      {
        QgsFeatureIds &handledFeatureIds = context->mHandledFeatures[this];
        if ( handledFeatureIds.contains( fid ) )
        {
          // avoid endless recursion
          return false;
        }
        else
        {
          // add feature id
          handledFeatureIds << fid;
        }
      }
      else
      {
        // add layer and feature id
        context->mHandledFeatures.insert( this, QgsFeatureIds() << fid );
      }
 
      for ( const QgsRelation &relation : relations )
      {
        //check if composition (and not association)
        switch ( relation.strength() )
        {
          case Qgis::RelationshipStrength::Composition:
          {
            //get features connected over this relation
            QgsFeatureIterator relatedFeaturesIt = relation.getRelatedFeatures( getFeature( fid ) );
            QgsFeatureIds childFeatureIds;
            QgsFeature childFeature;
            while ( relatedFeaturesIt.nextFeature( childFeature ) )
            {
              childFeatureIds.insert( childFeature.id() );
            }
            if ( childFeatureIds.count() > 0 )
            {
              relation.referencingLayer()->startEditing();
              relation.referencingLayer()->deleteFeatures( childFeatureIds, context );
            }
            break;
          }
 
          case Qgis::RelationshipStrength::Association:
            break;
        }
      }
    }
  }
 
  if ( mJoinBuffer->containsJoins() )
    mJoinBuffer->deleteFeature( fid, context );
 
  bool res = mEditBuffer->deleteFeature( fid );
 
  return res;
}
 
bool QgsVectorLayer::deleteFeature( QgsFeatureId fid, QgsVectorLayer::DeleteContext *context )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !mEditBuffer )
    return false;
 
  return deleteFeatureCascade( fid, context );
}
 
bool QgsVectorLayer::deleteFeatures( const QgsFeatureIds &fids, QgsVectorLayer::DeleteContext *context )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  bool res = true;
 
  if ( ( context && context->cascade ) || mJoinBuffer->containsJoins() )
  {
    // should ideally be "deleteFeaturesCascade" for performance!
    for ( QgsFeatureId fid : fids )
      res = deleteFeatureCascade( fid, context ) && res;
  }
  else
  {
    res = mEditBuffer && mEditBuffer->deleteFeatures( fids );
  }
 
  if ( res )
  {
    mSelectedFeatureIds.subtract( fids ); // remove it from selection
    updateExtents();
  }
 
  return res;
}
 
QgsFields QgsVectorLayer::fields() const
{
  // non fatal for now -- the "rasterize" processing algorithm is not thread safe and calls this
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS_NON_FATAL
 
  return mFields;
}
 
QgsAttributeList QgsVectorLayer::primaryKeyAttributes() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QgsAttributeList pkAttributesList;
  if ( !mDataProvider )
    return pkAttributesList;
 
  QgsAttributeList providerIndexes = mDataProvider->pkAttributeIndexes();
  for ( int i = 0; i < mFields.count(); ++i )
  {
    if ( mFields.fieldOrigin( i ) == Qgis::FieldOrigin::Provider && providerIndexes.contains( mFields.fieldOriginIndex( i ) ) )
      pkAttributesList << i;
  }
 
  return pkAttributesList;
}
 
long long QgsVectorLayer::featureCount() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !mDataProvider )
    return static_cast< long long >( Qgis::FeatureCountState::UnknownCount );
  return mDataProvider->featureCount() + ( mEditBuffer && !mDataProvider->transaction() ? mEditBuffer->addedFeatures().size() - mEditBuffer->deletedFeatureIds().size() : 0 );
}
 
Qgis::FeatureAvailability QgsVectorLayer::hasFeatures() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  const QgsFeatureIds deletedFeatures( mEditBuffer && !mDataProvider->transaction() ? mEditBuffer->deletedFeatureIds() : QgsFeatureIds() );
  const QgsFeatureMap addedFeatures( mEditBuffer && !mDataProvider->transaction() ? mEditBuffer->addedFeatures() : QgsFeatureMap() );
 
  if ( mEditBuffer && !deletedFeatures.empty() )
  {
    if ( addedFeatures.size() > deletedFeatures.size() )
      return Qgis::FeatureAvailability::FeaturesAvailable;
    else
      return Qgis::FeatureAvailability::FeaturesMaybeAvailable;
  }
 
  if ( ( !mEditBuffer || addedFeatures.empty() ) && mDataProvider && mDataProvider->empty() )
    return Qgis::FeatureAvailability::NoFeaturesAvailable;
  else
    return Qgis::FeatureAvailability::FeaturesAvailable;
}
 
bool QgsVectorLayer::commitChanges( bool stopEditing )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( project() && project()->transactionMode() == Qgis::TransactionMode::BufferedGroups )
    return project()->commitChanges( mCommitErrors, stopEditing, this );
 
  mCommitErrors.clear();
 
  if ( !mDataProvider )
  {
    mCommitErrors << tr( "ERROR: no provider" );
    return false;
  }
 
  if ( !mEditBuffer )
  {
    mCommitErrors << tr( "ERROR: layer not editable" );
    return false;
  }
 
  emit beforeCommitChanges( stopEditing );
 
  if ( !mAllowCommit )
    return false;
 
  mCommitChangesActive = true;
 
  bool success = false;
  if ( mEditBuffer->editBufferGroup() )
    success = mEditBuffer->editBufferGroup()->commitChanges( mCommitErrors, stopEditing );
  else
    success = mEditBuffer->commitChanges( mCommitErrors );
 
  mCommitChangesActive = false;
 
  if ( !mDeletedFids.empty() )
  {
    emit featuresDeleted( mDeletedFids );
    mDeletedFids.clear();
  }
 
  if ( success )
  {
    if ( stopEditing )
    {
      clearEditBuffer();
    }
    undoStack()->clear();
    emit afterCommitChanges();
    if ( stopEditing )
      emit editingStopped();
  }
  else
  {
    QgsMessageLog::logMessage( tr( "Commit errors:\n  %1" ).arg( mCommitErrors.join( "\n  "_L1 ) ) );
  }
 
  updateFields();
 
  mDataProvider->updateExtents();
 
  if ( stopEditing )
  {
    mDataProvider->leaveUpdateMode();
  }
 
  // This second call is required because OGR provider with JSON
  // driver might have changed fields order after the call to
  // leaveUpdateMode
  if ( mFields.names() != mDataProvider->fields().names() )
  {
    updateFields();
  }
 
  triggerRepaint();
 
  return success;
}
 
QStringList QgsVectorLayer::commitErrors() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return mCommitErrors;
}
 
bool QgsVectorLayer::rollBack( bool deleteBuffer )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( project() && project()->transactionMode() == Qgis::TransactionMode::BufferedGroups )
    return project()->rollBack( mCommitErrors, deleteBuffer, this );
 
  if ( !mEditBuffer )
  {
    return false;
  }
 
  if ( !mDataProvider )
  {
    mCommitErrors << tr( "ERROR: no provider" );
    return false;
  }
 
  bool rollbackExtent = !mDataProvider->transaction() && ( !mEditBuffer->deletedFeatureIds().isEmpty() || !mEditBuffer->addedFeatures().isEmpty() || !mEditBuffer->changedGeometries().isEmpty() );
 
  emit beforeRollBack();
 
  mEditBuffer->rollBack();
 
  emit afterRollBack();
 
  if ( isModified() )
  {
    // new undo stack roll back method
    // old method of calling every undo could cause many canvas refreshes
    undoStack()->setIndex( 0 );
  }
 
  updateFields();
 
  if ( deleteBuffer )
  {
    delete mEditBuffer;
    mEditBuffer = nullptr;
    undoStack()->clear();
  }
  emit editingStopped();
 
  if ( rollbackExtent )
    updateExtents();
 
  mDataProvider->leaveUpdateMode();
 
  triggerRepaint();
  return true;
}
 
int QgsVectorLayer::selectedFeatureCount() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return mSelectedFeatureIds.size();
}
 
const QgsFeatureIds &QgsVectorLayer::selectedFeatureIds() const
{
  // non fatal for now -- the "rasterize" processing algorithm is not thread safe and calls this
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS_NON_FATAL
 
  return mSelectedFeatureIds;
}
 
QgsFeatureList QgsVectorLayer::selectedFeatures() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QgsFeatureList features;
  features.reserve( mSelectedFeatureIds.count() );
  QgsFeature f;
 
  QgsFeatureIterator it = getSelectedFeatures();
 
  while ( it.nextFeature( f ) )
  {
    features.push_back( f );
  }
 
  return features;
}
 
QgsFeatureIterator QgsVectorLayer::getSelectedFeatures( QgsFeatureRequest request ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( mSelectedFeatureIds.isEmpty() )
    return QgsFeatureIterator();
 
  if ( geometryType() == Qgis::GeometryType::Null )
    request.setFlags( Qgis::FeatureRequestFlag::NoGeometry );
 
  if ( mSelectedFeatureIds.count() == 1 )
    request.setFilterFid( *mSelectedFeatureIds.constBegin() );
  else
    request.setFilterFids( mSelectedFeatureIds );
 
  return getFeatures( request );
}
 
bool QgsVectorLayer::addFeatures( QgsFeatureList &features, Flags )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !mEditBuffer || !mDataProvider )
    return false;
 
  if ( mGeometryOptions->isActive() )
  {
    for ( auto feature = features.begin(); feature != features.end(); ++feature )
    {
      QgsGeometry geom = feature->geometry();
      mGeometryOptions->apply( geom );
      feature->setGeometry( geom );
    }
  }
 
  bool res = mEditBuffer->addFeatures( features );
  updateExtents();
 
  if ( res && mJoinBuffer->containsJoins() )
    res = mJoinBuffer->addFeatures( features );
 
  return res;
}
 
void QgsVectorLayer::setCoordinateSystem()
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  // if layer is not spatial, it has not CRS!
  setCrs( ( isSpatial() && mDataProvider ) ? mDataProvider->crs() : QgsCoordinateReferenceSystem() );
}
 
QString QgsVectorLayer::displayField() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QgsExpression exp( displayExpression() );
  if ( exp.isField() )
  {
    return static_cast<const QgsExpressionNodeColumnRef *>( exp.rootNode() )->name();
  }
 
  return QString();
}
 
void QgsVectorLayer::setDisplayExpression( const QString &displayExpression )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( mDisplayExpression == displayExpression )
    return;
 
  mDisplayExpression = displayExpression;
  emit displayExpressionChanged();
}
 
QString QgsVectorLayer::displayExpression() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !mDisplayExpression.isEmpty() || mFields.isEmpty() )
  {
    return mDisplayExpression;
  }
  else
  {
    const QString candidateName = QgsVectorLayerUtils::guessFriendlyIdentifierField( mFields );
    if ( !candidateName.isEmpty() )
    {
      return QgsExpression::quotedColumnRef( candidateName );
    }
    else
    {
      return QString();
    }
  }
}
 
bool QgsVectorLayer::hasMapTips() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  // display expressions are used as a fallback when no explicit map tip template is set
  return mapTipsEnabled() && ( !mapTipTemplate().isEmpty() || !displayExpression().isEmpty() );
}
 
bool QgsVectorLayer::isEditable() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return ( mEditBuffer && mDataProvider );
}
 
bool QgsVectorLayer::isSpatial() const
{
  // non fatal for now -- the "rasterize" processing algorithm is not thread safe and calls this
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS_NON_FATAL
 
  Qgis::GeometryType t = geometryType();
  return t != Qgis::GeometryType::Null && t != Qgis::GeometryType::Unknown;
}
 
bool QgsVectorLayer::isReadOnly() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return mDataSourceReadOnly || mReadOnly;
}
 
bool QgsVectorLayer::setReadOnly( bool readonly )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  // exit if the layer is in editing mode
  if ( readonly && mEditBuffer )
    return false;
 
  // exit if the data source is in read-only mode
  if ( !readonly && mDataSourceReadOnly )
    return false;
 
  mReadOnly = readonly;
  emit readOnlyChanged();
  return true;
}
 
bool QgsVectorLayer::supportsEditing() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !mDataProvider )
    return false;
 
  if ( mDataSourceReadOnly )
    return false;
 
  return mDataProvider->capabilities() & QgsVectorDataProvider::EditingCapabilities && !mReadOnly;
}
 
bool QgsVectorLayer::isModified() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  emit beforeModifiedCheck();
  return mEditBuffer && mEditBuffer->isModified();
}
 
bool QgsVectorLayer::isAuxiliaryField( int index, int &srcIndex ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  bool auxiliaryField = false;
  srcIndex = -1;
 
  if ( !auxiliaryLayer() )
    return auxiliaryField;
 
  if ( index >= 0 && fields().fieldOrigin( index ) == Qgis::FieldOrigin::Join )
  {
    const QgsVectorLayerJoinInfo *info = mJoinBuffer->joinForFieldIndex( index, fields(), srcIndex );
 
    if ( info && info->joinLayerId() == auxiliaryLayer()->id() )
      auxiliaryField = true;
  }
 
  return auxiliaryField;
}
 
void QgsVectorLayer::setRenderer( QgsFeatureRenderer *r )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  // we must allow setting a renderer if our geometry type is unknown
  // as this allows the renderer to be correctly set even for layers
  // with broken sources
  // (note that we allow REMOVING the renderer for non-spatial layers,
  // e.g. to permit removing the renderer when the layer changes from
  // a spatial layer to a non-spatial one)
  if ( r && !isSpatial() && mWkbType != Qgis::WkbType::Unknown )
    return;
 
  if ( r != mRenderer )
  {
    delete mRenderer;
    mRenderer = r;
    mSymbolFeatureCounted = false;
    mSymbolFeatureCountMap.clear();
    mSymbolFeatureIdMap.clear();
 
    if ( mRenderer )
    {
      const double refreshRate = QgsSymbolLayerUtils::rendererFrameRate( mRenderer );
      if ( refreshRate <= 0 )
      {
        mRefreshRendererTimer->stop();
        mRefreshRendererTimer->setInterval( 0 );
      }
      else
      {
        mRefreshRendererTimer->setInterval( 1000 / refreshRate );
        mRefreshRendererTimer->start();
      }
    }
 
    emit rendererChanged();
    emitStyleChanged();
  }
}
 
void QgsVectorLayer::addFeatureRendererGenerator( QgsFeatureRendererGenerator *generator )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( generator )
  {
    mRendererGenerators << generator;
  }
}
 
void QgsVectorLayer::removeFeatureRendererGenerator( const QString &id )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  for ( int i = mRendererGenerators.count() - 1; i >= 0; --i )
  {
    if ( mRendererGenerators.at( i )->id() == id )
    {
      delete mRendererGenerators.at( i );
      mRendererGenerators.removeAt( i );
    }
  }
}
 
QList<const QgsFeatureRendererGenerator *> QgsVectorLayer::featureRendererGenerators() const
{
  // non fatal for now -- the "rasterize" processing algorithm is not thread safe and calls this
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS_NON_FATAL
 
  QList< const QgsFeatureRendererGenerator * > res;
  for ( const QgsFeatureRendererGenerator *generator : mRendererGenerators )
    res << generator;
  return res;
}
 
void QgsVectorLayer::beginEditCommand( const QString &text )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !mDataProvider )
  {
    return;
  }
  if ( mDataProvider->transaction() )
  {
    QString ignoredError;
    mDataProvider->transaction()->createSavepoint( ignoredError );
  }
  undoStack()->beginMacro( text );
  mEditCommandActive = true;
  emit editCommandStarted( text );
}
 
void QgsVectorLayer::endEditCommand()
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !mDataProvider )
  {
    return;
  }
  undoStack()->endMacro();
  mEditCommandActive = false;
  if ( !mDeletedFids.isEmpty() )
  {
    if ( selectedFeatureCount() > 0 )
    {
      mSelectedFeatureIds.subtract( mDeletedFids );
    }
    emit featuresDeleted( mDeletedFids );
    mDeletedFids.clear();
  }
  emit editCommandEnded();
}
 
void QgsVectorLayer::destroyEditCommand()
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !mDataProvider )
  {
    return;
  }
  undoStack()->endMacro();
  undoStack()->undo();
 
  // it's not directly possible to pop the last command off the stack (the destroyed one)
  // and delete, so we add a dummy obsolete command to force this to occur.
  // Pushing the new command deletes the destroyed one, and since the new
  // command is obsolete it's automatically deleted by the undo stack.
  auto command = std::make_unique< QUndoCommand >();
  command->setObsolete( true );
  undoStack()->push( command.release() );
 
  mEditCommandActive = false;
  mDeletedFids.clear();
  emit editCommandDestroyed();
}
 
bool QgsVectorLayer::addJoin( const QgsVectorLayerJoinInfo &joinInfo )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return mJoinBuffer->addJoin( joinInfo );
}
 
bool QgsVectorLayer::removeJoin( const QString &joinLayerId )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return mJoinBuffer->removeJoin( joinLayerId );
}
 
const QList< QgsVectorLayerJoinInfo > QgsVectorLayer::vectorJoins() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return mJoinBuffer->vectorJoins();
}
 
int QgsVectorLayer::addExpressionField( const QString &exp, const QgsField &fld )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  emit beforeAddingExpressionField( fld.name() );
  mExpressionFieldBuffer->addExpression( exp, fld );
  updateFields();
  int idx = mFields.indexFromName( fld.name() );
  emit attributeAdded( idx );
  return idx;
}
 
void QgsVectorLayer::removeExpressionField( int index )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  emit beforeRemovingExpressionField( index );
  int oi = mFields.fieldOriginIndex( index );
  mExpressionFieldBuffer->removeExpression( oi );
  updateFields();
  emit attributeDeleted( index );
}
 
QString QgsVectorLayer::expressionField( int index ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( mFields.fieldOrigin( index ) != Qgis::FieldOrigin::Expression )
    return QString();
 
  int oi = mFields.fieldOriginIndex( index );
  if ( oi < 0 || oi >= mExpressionFieldBuffer->expressions().size() )
    return QString();
 
  return mExpressionFieldBuffer->expressions().at( oi ).cachedExpression.expression();
}
 
void QgsVectorLayer::updateExpressionField( int index, const QString &exp )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  int oi = mFields.fieldOriginIndex( index );
  mExpressionFieldBuffer->updateExpression( oi, exp );
}
 
void QgsVectorLayer::updateFields()
{
  // non fatal for now -- the QgsVirtualLayerTask class is not thread safe and calls this
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS_NON_FATAL
 
  if ( !mDataProvider )
    return;
 
  QgsFields oldFields = mFields;
 
  mFields = mDataProvider->fields();
 
  // added / removed fields
  if ( mEditBuffer )
    mEditBuffer->updateFields( mFields );
 
  // joined fields
  if ( mJoinBuffer->containsJoins() )
    mJoinBuffer->updateFields( mFields );
 
  if ( mExpressionFieldBuffer )
    mExpressionFieldBuffer->updateFields( mFields );
 
  // set aliases and default values
  for ( auto aliasIt = mAttributeAliasMap.constBegin(); aliasIt != mAttributeAliasMap.constEnd(); ++aliasIt )
  {
    int index = mFields.lookupField( aliasIt.key() );
    if ( index < 0 )
      continue;
 
    mFields[index].setAlias( aliasIt.value() );
  }
 
  // set custom comments
  for ( auto customCommentIt = mAttributeCustomCommentMap.constBegin(); customCommentIt != mAttributeCustomCommentMap.constEnd(); ++customCommentIt )
  {
    int index = mFields.lookupField( customCommentIt.key() );
    if ( index < 0 )
      continue;
 
    mFields[index].setCustomComment( customCommentIt.value() );
  }
 
  for ( auto splitPolicyIt = mAttributeSplitPolicy.constBegin(); splitPolicyIt != mAttributeSplitPolicy.constEnd(); ++splitPolicyIt )
  {
    int index = mFields.lookupField( splitPolicyIt.key() );
    if ( index < 0 )
      continue;
 
    mFields[index].setSplitPolicy( splitPolicyIt.value() );
  }
 
  for ( auto duplicatePolicyIt = mAttributeDuplicatePolicy.constBegin(); duplicatePolicyIt != mAttributeDuplicatePolicy.constEnd(); ++duplicatePolicyIt )
  {
    int index = mFields.lookupField( duplicatePolicyIt.key() );
    if ( index < 0 )
      continue;
 
    mFields[index].setDuplicatePolicy( duplicatePolicyIt.value() );
  }
 
  for ( auto mergePolicyIt = mAttributeMergePolicy.constBegin(); mergePolicyIt != mAttributeMergePolicy.constEnd(); ++mergePolicyIt )
  {
    int index = mFields.lookupField( mergePolicyIt.key() );
    if ( index < 0 )
      continue;
 
    mFields[index].setMergePolicy( mergePolicyIt.value() );
  }
 
  // Update configuration flags
  QMap< QString, Qgis::FieldConfigurationFlags >::const_iterator flagsIt = mFieldConfigurationFlags.constBegin();
  for ( ; flagsIt != mFieldConfigurationFlags.constEnd(); ++flagsIt )
  {
    int index = mFields.lookupField( flagsIt.key() );
    if ( index < 0 )
      continue;
 
    mFields[index].setConfigurationFlags( flagsIt.value() );
  }
 
  // Update default values
  mDefaultValueOnUpdateFields.clear();
  QMap< QString, QgsDefaultValue >::const_iterator defaultIt = mDefaultExpressionMap.constBegin();
  for ( ; defaultIt != mDefaultExpressionMap.constEnd(); ++defaultIt )
  {
    int index = mFields.lookupField( defaultIt.key() );
    if ( index < 0 )
      continue;
 
    mFields[index].setDefaultValueDefinition( defaultIt.value() );
    if ( defaultIt.value().applyOnUpdate() )
      mDefaultValueOnUpdateFields.insert( index );
  }
 
  QMap< QString, QgsFieldConstraints::Constraints >::const_iterator constraintIt = mFieldConstraints.constBegin();
  for ( ; constraintIt != mFieldConstraints.constEnd(); ++constraintIt )
  {
    int index = mFields.lookupField( constraintIt.key() );
    if ( index < 0 )
      continue;
 
    QgsFieldConstraints constraints = mFields.at( index ).constraints();
 
    // always keep provider constraints intact
    if ( !( constraints.constraints() & QgsFieldConstraints::ConstraintNotNull ) && ( constraintIt.value() & QgsFieldConstraints::ConstraintNotNull ) )
      constraints.setConstraint( QgsFieldConstraints::ConstraintNotNull, QgsFieldConstraints::ConstraintOriginLayer );
    if ( !( constraints.constraints() & QgsFieldConstraints::ConstraintUnique ) && ( constraintIt.value() & QgsFieldConstraints::ConstraintUnique ) )
      constraints.setConstraint( QgsFieldConstraints::ConstraintUnique, QgsFieldConstraints::ConstraintOriginLayer );
    if ( !( constraints.constraints() & QgsFieldConstraints::ConstraintExpression ) && ( constraintIt.value() & QgsFieldConstraints::ConstraintExpression ) )
      constraints.setConstraint( QgsFieldConstraints::ConstraintExpression, QgsFieldConstraints::ConstraintOriginLayer );
    mFields[index].setConstraints( constraints );
  }
 
  QMap< QString, QPair< QString, QString > >::const_iterator constraintExpIt = mFieldConstraintExpressions.constBegin();
  for ( ; constraintExpIt != mFieldConstraintExpressions.constEnd(); ++constraintExpIt )
  {
    int index = mFields.lookupField( constraintExpIt.key() );
    if ( index < 0 )
      continue;
 
    QgsFieldConstraints constraints = mFields.at( index ).constraints();
 
    // always keep provider constraints intact
    if ( constraints.constraintOrigin( QgsFieldConstraints::ConstraintExpression ) == QgsFieldConstraints::ConstraintOriginProvider )
      continue;
 
    constraints.setConstraintExpression( constraintExpIt.value().first, constraintExpIt.value().second );
    mFields[index].setConstraints( constraints );
  }
 
  QMap< QPair< QString, QgsFieldConstraints::Constraint >, QgsFieldConstraints::ConstraintStrength >::const_iterator constraintStrengthIt = mFieldConstraintStrength.constBegin();
  for ( ; constraintStrengthIt != mFieldConstraintStrength.constEnd(); ++constraintStrengthIt )
  {
    int index = mFields.lookupField( constraintStrengthIt.key().first );
    if ( index < 0 )
      continue;
 
    QgsFieldConstraints constraints = mFields.at( index ).constraints();
 
    // always keep provider constraints intact
    if ( constraints.constraintOrigin( QgsFieldConstraints::ConstraintExpression ) == QgsFieldConstraints::ConstraintOriginProvider )
      continue;
 
    constraints.setConstraintStrength( constraintStrengthIt.key().second, constraintStrengthIt.value() );
    mFields[index].setConstraints( constraints );
  }
 
  auto fieldWidgetIterator = mFieldWidgetSetups.constBegin();
  for ( ; fieldWidgetIterator != mFieldWidgetSetups.constEnd(); ++fieldWidgetIterator )
  {
    int index = mFields.indexOf( fieldWidgetIterator.key() );
    if ( index < 0 )
      continue;
 
    mFields[index].setEditorWidgetSetup( fieldWidgetIterator.value() );
  }
 
  if ( oldFields != mFields )
  {
    emit updatedFields();
    mEditFormConfig.setFields( mFields );
  }
}
 
QVariant QgsVectorLayer::defaultValue( int index, const QgsFeature &feature, QgsExpressionContext *context ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( index < 0 || index >= mFields.count() || !mDataProvider )
    return QVariant();
 
  QString expression = mFields.at( index ).defaultValueDefinition().expression();
  if ( expression.isEmpty() )
    return mDataProvider->defaultValue( index );
 
  QgsExpressionContext *evalContext = context;
  std::unique_ptr< QgsExpressionContext > tempContext;
  if ( !evalContext )
  {
    // no context passed, so we create a default one
    tempContext = std::make_unique<QgsExpressionContext>( QgsExpressionContextUtils::globalProjectLayerScopes( this ) );
    evalContext = tempContext.get();
  }
 
  if ( feature.isValid() )
  {
    QgsExpressionContextScope *featScope = new QgsExpressionContextScope();
    featScope->setFeature( feature );
    featScope->setFields( feature.fields() );
    evalContext->appendScope( featScope );
  }
 
  QVariant val;
  QgsExpression exp( expression );
  exp.prepare( evalContext );
  if ( exp.hasEvalError() )
  {
    QgsLogger::warning( "Error evaluating default value: " + exp.evalErrorString() );
  }
  else
  {
    val = exp.evaluate( evalContext );
  }
 
  if ( feature.isValid() )
  {
    delete evalContext->popScope();
  }
 
  return val;
}
 
void QgsVectorLayer::setDefaultValueDefinition( int index, const QgsDefaultValue &definition )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( index < 0 || index >= mFields.count() )
    return;
 
  if ( definition.isValid() )
  {
    mDefaultExpressionMap.insert( mFields.at( index ).name(), definition );
  }
  else
  {
    mDefaultExpressionMap.remove( mFields.at( index ).name() );
  }
  updateFields();
}
 
QgsDefaultValue QgsVectorLayer::defaultValueDefinition( int index ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( index < 0 || index >= mFields.count() )
    return QgsDefaultValue();
  else
    return mFields.at( index ).defaultValueDefinition();
}
 
QSet<QVariant> QgsVectorLayer::uniqueValues( int index, int limit ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QSet<QVariant> uniqueValues;
  if ( !mDataProvider )
  {
    return uniqueValues;
  }
 
  Qgis::FieldOrigin origin = mFields.fieldOrigin( index );
  switch ( origin )
  {
    case Qgis::FieldOrigin::Unknown:
      return uniqueValues;
 
    case Qgis::FieldOrigin::Provider: //a provider field
    {
      uniqueValues = mDataProvider->uniqueValues( index, limit );
 
      if ( mEditBuffer && !mDataProvider->transaction() )
      {
        QSet<QString> vals;
        const auto constUniqueValues = uniqueValues;
        for ( const QVariant &v : constUniqueValues )
        {
          vals << v.toString();
        }
 
        QgsFeatureMap added = mEditBuffer->addedFeatures();
        QMapIterator< QgsFeatureId, QgsFeature > addedIt( added );
        while ( addedIt.hasNext() && ( limit < 0 || uniqueValues.count() < limit ) )
        {
          addedIt.next();
          QVariant v = addedIt.value().attribute( index );
          if ( v.isValid() )
          {
            QString vs = v.toString();
            if ( !vals.contains( vs ) )
            {
              vals << vs;
              uniqueValues << v;
            }
          }
        }
 
        QMapIterator< QgsFeatureId, QgsAttributeMap > it( mEditBuffer->changedAttributeValues() );
        while ( it.hasNext() && ( limit < 0 || uniqueValues.count() < limit ) )
        {
          it.next();
          QVariant v = it.value().value( index );
          if ( v.isValid() )
          {
            QString vs = v.toString();
            if ( !vals.contains( vs ) )
            {
              vals << vs;
              uniqueValues << v;
            }
          }
        }
      }
 
      return uniqueValues;
    }
 
    case Qgis::FieldOrigin::Edit:
      // the layer is editable, but in certain cases it can still be avoided going through all features
      if ( mDataProvider->transaction()
           || ( mEditBuffer->deletedFeatureIds().isEmpty() && mEditBuffer->addedFeatures().isEmpty() && !mEditBuffer->deletedAttributeIds().contains( index ) && mEditBuffer->changedAttributeValues().isEmpty() ) )
      {
        uniqueValues = mDataProvider->uniqueValues( index, limit );
        return uniqueValues;
      }
      [[fallthrough]];
    //we need to go through each feature
    case Qgis::FieldOrigin::Join:
    case Qgis::FieldOrigin::Expression:
    {
      QgsAttributeList attList;
      attList << index;
 
      QgsFeatureIterator fit = getFeatures( QgsFeatureRequest().setFlags( Qgis::FeatureRequestFlag::NoGeometry ).setSubsetOfAttributes( attList ) );
 
      QgsFeature f;
      QVariant currentValue;
      QHash<QString, QVariant> val;
      while ( fit.nextFeature( f ) )
      {
        currentValue = f.attribute( index );
        val.insert( currentValue.toString(), currentValue );
        if ( limit >= 0 && val.size() >= limit )
        {
          break;
        }
      }
 
      return qgis::listToSet( val.values() );
    }
  }
 
  Q_ASSERT_X( false, "QgsVectorLayer::uniqueValues()", "Unknown source of the field!" );
  return uniqueValues;
}
 
QStringList QgsVectorLayer::uniqueStringsMatching( int index, const QString &substring, int limit, QgsFeedback *feedback ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QStringList results;
  if ( !mDataProvider )
  {
    return results;
  }
 
  Qgis::FieldOrigin origin = mFields.fieldOrigin( index );
  switch ( origin )
  {
    case Qgis::FieldOrigin::Unknown:
      return results;
 
    case Qgis::FieldOrigin::Provider: //a provider field
    {
      results = mDataProvider->uniqueStringsMatching( index, substring, limit, feedback );
 
      if ( mEditBuffer && !mDataProvider->transaction() )
      {
        QgsFeatureMap added = mEditBuffer->addedFeatures();
        QMapIterator< QgsFeatureId, QgsFeature > addedIt( added );
        while ( addedIt.hasNext() && ( limit < 0 || results.count() < limit ) && ( !feedback || !feedback->isCanceled() ) )
        {
          addedIt.next();
          QVariant v = addedIt.value().attribute( index );
          if ( v.isValid() )
          {
            QString vs = v.toString();
            if ( vs.contains( substring, Qt::CaseInsensitive ) && !results.contains( vs ) )
            {
              results << vs;
            }
          }
        }
 
        QMapIterator< QgsFeatureId, QgsAttributeMap > it( mEditBuffer->changedAttributeValues() );
        while ( it.hasNext() && ( limit < 0 || results.count() < limit ) && ( !feedback || !feedback->isCanceled() ) )
        {
          it.next();
          QVariant v = it.value().value( index );
          if ( v.isValid() )
          {
            QString vs = v.toString();
            if ( vs.contains( substring, Qt::CaseInsensitive ) && !results.contains( vs ) )
            {
              results << vs;
            }
          }
        }
      }
 
      return results;
    }
 
    case Qgis::FieldOrigin::Edit:
      // the layer is editable, but in certain cases it can still be avoided going through all features
      if ( mDataProvider->transaction()
           || ( mEditBuffer->deletedFeatureIds().isEmpty() && mEditBuffer->addedFeatures().isEmpty() && !mEditBuffer->deletedAttributeIds().contains( index ) && mEditBuffer->changedAttributeValues().isEmpty() ) )
      {
        return mDataProvider->uniqueStringsMatching( index, substring, limit, feedback );
      }
      [[fallthrough]];
    //we need to go through each feature
    case Qgis::FieldOrigin::Join:
    case Qgis::FieldOrigin::Expression:
    {
      QgsAttributeList attList;
      attList << index;
 
      QgsFeatureRequest request;
      request.setSubsetOfAttributes( attList );
      request.setFlags( Qgis::FeatureRequestFlag::NoGeometry );
      QString fieldName = mFields.at( index ).name();
      request.setFilterExpression( u"\"%1\" ILIKE '%%2%'"_s.arg( fieldName, substring ) );
      QgsFeatureIterator fit = getFeatures( request );
 
      QgsFeature f;
      QString currentValue;
      while ( fit.nextFeature( f ) )
      {
        currentValue = f.attribute( index ).toString();
        if ( !results.contains( currentValue ) )
          results << currentValue;
 
        if ( ( limit >= 0 && results.size() >= limit ) || ( feedback && feedback->isCanceled() ) )
        {
          break;
        }
      }
 
      return results;
    }
  }
 
  Q_ASSERT_X( false, "QgsVectorLayer::uniqueStringsMatching()", "Unknown source of the field!" );
  return results;
}
 
QVariant QgsVectorLayer::minimumValue( int index ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QVariant minimum;
  minimumOrMaximumValue( index, &minimum, nullptr );
  return minimum;
}
 
QVariant QgsVectorLayer::maximumValue( int index ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QVariant maximum;
  minimumOrMaximumValue( index, nullptr, &maximum );
  return maximum;
}
 
void QgsVectorLayer::minimumAndMaximumValue( int index, QVariant &minimum, QVariant &maximum ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  minimumOrMaximumValue( index, &minimum, &maximum );
}
 
void QgsVectorLayer::minimumOrMaximumValue( int index, QVariant *minimum, QVariant *maximum ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( minimum )
    *minimum = QVariant();
  if ( maximum )
    *maximum = QVariant();
 
  if ( !mDataProvider )
  {
    return;
  }
 
  Qgis::FieldOrigin origin = mFields.fieldOrigin( index );
 
  switch ( origin )
  {
    case Qgis::FieldOrigin::Unknown:
    {
      return;
    }
 
    case Qgis::FieldOrigin::Provider: //a provider field
    {
      if ( minimum )
        *minimum = mDataProvider->minimumValue( index );
      if ( maximum )
        *maximum = mDataProvider->maximumValue( index );
      if ( mEditBuffer && !mDataProvider->transaction() )
      {
        const QgsFeatureMap added = mEditBuffer->addedFeatures();
        QMapIterator< QgsFeatureId, QgsFeature > addedIt( added );
        while ( addedIt.hasNext() )
        {
          addedIt.next();
          const QVariant v = addedIt.value().attribute( index );
          if ( minimum && v.isValid() && qgsVariantLessThan( v, *minimum ) )
            *minimum = v;
          if ( maximum && v.isValid() && qgsVariantGreaterThan( v, *maximum ) )
            *maximum = v;
        }
 
        QMapIterator< QgsFeatureId, QgsAttributeMap > it( mEditBuffer->changedAttributeValues() );
        while ( it.hasNext() )
        {
          it.next();
          const QVariant v = it.value().value( index );
          if ( minimum && v.isValid() && qgsVariantLessThan( v, *minimum ) )
            *minimum = v;
          if ( maximum && v.isValid() && qgsVariantGreaterThan( v, *maximum ) )
            *maximum = v;
        }
      }
      return;
    }
 
    case Qgis::FieldOrigin::Edit:
    {
      // the layer is editable, but in certain cases it can still be avoided going through all features
      if ( mDataProvider->transaction()
           || ( mEditBuffer->deletedFeatureIds().isEmpty() && mEditBuffer->addedFeatures().isEmpty() && !mEditBuffer->deletedAttributeIds().contains( index ) && mEditBuffer->changedAttributeValues().isEmpty() ) )
      {
        if ( minimum )
          *minimum = mDataProvider->minimumValue( index );
        if ( maximum )
          *maximum = mDataProvider->maximumValue( index );
        return;
      }
    }
      [[fallthrough]];
    // no choice but to go through all features
    case Qgis::FieldOrigin::Expression:
    case Qgis::FieldOrigin::Join:
    {
      // we need to go through each feature
      QgsAttributeList attList;
      attList << index;
 
      QgsFeatureIterator fit = getFeatures( QgsFeatureRequest().setFlags( Qgis::FeatureRequestFlag::NoGeometry ).setSubsetOfAttributes( attList ) );
 
      QgsFeature f;
      bool firstValue = true;
      while ( fit.nextFeature( f ) )
      {
        const QVariant currentValue = f.attribute( index );
        if ( QgsVariantUtils::isNull( currentValue ) )
          continue;
 
        if ( firstValue )
        {
          if ( minimum )
            *minimum = currentValue;
          if ( maximum )
            *maximum = currentValue;
          firstValue = false;
        }
        else
        {
          if ( minimum && currentValue.isValid() && qgsVariantLessThan( currentValue, *minimum ) )
            *minimum = currentValue;
          if ( maximum && currentValue.isValid() && qgsVariantGreaterThan( currentValue, *maximum ) )
            *maximum = currentValue;
        }
      }
      return;
    }
  }
 
  Q_ASSERT_X( false, "QgsVectorLayer::minimumOrMaximumValue()", "Unknown source of the field!" );
}
 
void QgsVectorLayer::createEditBuffer()
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( mEditBuffer )
    clearEditBuffer();
 
  if ( mDataProvider->transaction() )
  {
    mEditBuffer = new QgsVectorLayerEditPassthrough( this );
 
    connect( mDataProvider->transaction(), &QgsTransaction::dirtied, this, &QgsVectorLayer::onDirtyTransaction, Qt::UniqueConnection );
  }
  else
  {
    mEditBuffer = new QgsVectorLayerEditBuffer( this );
  }
  // forward signals
  connect( mEditBuffer, &QgsVectorLayerEditBuffer::layerModified, this, &QgsVectorLayer::invalidateSymbolCountedFlag );
  connect( mEditBuffer, &QgsVectorLayerEditBuffer::layerModified, this, &QgsVectorLayer::layerModified ); // TODO[MD]: necessary?
  //connect( mEditBuffer, &QgsVectorLayerEditBuffer::layerModified, this, &QgsVectorLayer::triggerRepaint ); // TODO[MD]: works well?
  connect( mEditBuffer, &QgsVectorLayerEditBuffer::featureAdded, this, &QgsVectorLayer::onFeatureAdded );
  connect( mEditBuffer, &QgsVectorLayerEditBuffer::featureDeleted, this, &QgsVectorLayer::onFeatureDeleted );
  connect( mEditBuffer, &QgsVectorLayerEditBuffer::geometryChanged, this, &QgsVectorLayer::geometryChanged );
  connect( mEditBuffer, &QgsVectorLayerEditBuffer::attributeValueChanged, this, &QgsVectorLayer::attributeValueChanged );
  connect( mEditBuffer, &QgsVectorLayerEditBuffer::attributeAdded, this, &QgsVectorLayer::attributeAdded );
  connect( mEditBuffer, &QgsVectorLayerEditBuffer::attributeDeleted, this, &QgsVectorLayer::attributeDeleted );
  connect( mEditBuffer, &QgsVectorLayerEditBuffer::committedAttributesDeleted, this, &QgsVectorLayer::committedAttributesDeleted );
  connect( mEditBuffer, &QgsVectorLayerEditBuffer::committedAttributesAdded, this, &QgsVectorLayer::committedAttributesAdded );
  connect( mEditBuffer, &QgsVectorLayerEditBuffer::committedFeaturesAdded, this, &QgsVectorLayer::committedFeaturesAdded );
  connect( mEditBuffer, &QgsVectorLayerEditBuffer::committedFeaturesRemoved, this, &QgsVectorLayer::committedFeaturesRemoved );
  connect( mEditBuffer, &QgsVectorLayerEditBuffer::committedAttributeValuesChanges, this, &QgsVectorLayer::committedAttributeValuesChanges );
  connect( mEditBuffer, &QgsVectorLayerEditBuffer::committedGeometriesChanges, this, &QgsVectorLayer::committedGeometriesChanges );
}
 
void QgsVectorLayer::clearEditBuffer()
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  delete mEditBuffer;
  mEditBuffer = nullptr;
}
 
QVariant QgsVectorLayer::aggregate(
  Qgis::Aggregate aggregate,
  const QString &fieldOrExpression,
  const QgsAggregateCalculator::AggregateParameters &parameters,
  QgsExpressionContext *context,
  bool *ok,
  QgsFeatureIds *fids,
  QgsFeedback *feedback,
  QString *error
) const
{
  // non fatal for now -- the aggregate expression functions are not thread safe and call this
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS_NON_FATAL
 
  if ( ok )
    *ok = false;
  if ( error )
    error->clear();
 
  if ( !mDataProvider )
  {
    if ( error )
      *error = tr( "Layer is invalid" );
    return QVariant();
  }
 
  // test if we are calculating based on a field
  const int attrIndex = QgsExpression::expressionToLayerFieldIndex( fieldOrExpression, this );
  if ( attrIndex >= 0 )
  {
    // aggregate is based on a field - if it's a provider field, we could possibly hand over the calculation
    // to the provider itself
    Qgis::FieldOrigin origin = mFields.fieldOrigin( attrIndex );
    if ( origin == Qgis::FieldOrigin::Provider )
    {
      bool providerOk = false;
      QVariant val = mDataProvider->aggregate( aggregate, attrIndex, parameters, context, providerOk, fids );
      if ( providerOk )
      {
        // provider handled calculation
        if ( ok )
          *ok = true;
        return val;
      }
    }
  }
 
  // fallback to using aggregate calculator to determine aggregate
  QgsAggregateCalculator c( this );
  if ( fids )
    c.setFidsFilter( *fids );
  c.setParameters( parameters );
  bool aggregateOk = false;
  const QVariant result = c.calculate( aggregate, fieldOrExpression, context, &aggregateOk, feedback );
  if ( ok )
    *ok = aggregateOk;
  if ( !aggregateOk && error )
    *error = c.lastError();
 
  return result;
}
 
void QgsVectorLayer::setFeatureBlendMode( QPainter::CompositionMode featureBlendMode )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( mFeatureBlendMode == featureBlendMode )
    return;
 
  mFeatureBlendMode = featureBlendMode;
  emit featureBlendModeChanged( featureBlendMode );
  emitStyleChanged();
}
 
QPainter::CompositionMode QgsVectorLayer::featureBlendMode() const
{
  // non fatal for now -- the "rasterize" processing algorithm is not thread safe and calls this
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS_NON_FATAL
 
  return mFeatureBlendMode;
}
 
void QgsVectorLayer::readSldLabeling( const QDomNode &node )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  setLabeling( nullptr ); // start with no labeling
  setLabelsEnabled( false );
 
  QDomElement element = node.toElement();
  if ( element.isNull() )
    return;
 
  QDomElement userStyleElem = element.firstChildElement( u"UserStyle"_s );
  if ( userStyleElem.isNull() )
  {
    QgsDebugMsgLevel( u"Info: UserStyle element not found."_s, 4 );
    return;
  }
 
  QDomElement featTypeStyleElem = userStyleElem.firstChildElement( u"FeatureTypeStyle"_s );
  if ( featTypeStyleElem.isNull() )
  {
    QgsDebugMsgLevel( u"Info: FeatureTypeStyle element not found."_s, 4 );
    return;
  }
 
  // create empty FeatureTypeStyle element to merge TextSymbolizer's Rule's from all FeatureTypeStyle's
  QDomElement mergedFeatTypeStyle = featTypeStyleElem.cloneNode( false ).toElement();
 
  // use the RuleRenderer when more rules are present or the rule
  // has filters or min/max scale denominators set,
  // otherwise use the Simple labeling
  bool needRuleBasedLabeling = false;
  int ruleCount = 0;
 
  while ( !featTypeStyleElem.isNull() )
  {
    QDomElement ruleElem = featTypeStyleElem.firstChildElement( u"Rule"_s );
    while ( !ruleElem.isNull() )
    {
      // test rule children element to check if we need to create RuleRenderer
      // and if the rule has a symbolizer
      bool hasTextSymbolizer = false;
      bool hasRuleBased = false;
      QDomElement ruleChildElem = ruleElem.firstChildElement();
      while ( !ruleChildElem.isNull() )
      {
        // rule has filter or min/max scale denominator, use the RuleRenderer
        if ( ruleChildElem.localName() == "Filter"_L1 || ruleChildElem.localName() == "MinScaleDenominator"_L1 || ruleChildElem.localName() == "MaxScaleDenominator"_L1 )
        {
          hasRuleBased = true;
        }
        // rule has a renderer symbolizer, not a text symbolizer
        else if ( ruleChildElem.localName() == "TextSymbolizer"_L1 )
        {
          QgsDebugMsgLevel( u"Info: TextSymbolizer element found"_s, 4 );
          hasTextSymbolizer = true;
        }
 
        ruleChildElem = ruleChildElem.nextSiblingElement();
      }
 
      if ( hasTextSymbolizer )
      {
        ruleCount++;
 
        // append a clone of all Rules to the merged FeatureTypeStyle element
        mergedFeatTypeStyle.appendChild( ruleElem.cloneNode().toElement() );
 
        if ( hasRuleBased )
        {
          QgsDebugMsgLevel( u"Info: Filter or Min/MaxScaleDenominator element found: need a RuleBasedLabeling"_s, 4 );
          needRuleBasedLabeling = true;
        }
      }
 
      // more rules present, use the RuleRenderer
      if ( ruleCount > 1 )
      {
        QgsDebugMsgLevel( u"Info: More Rule elements found: need a RuleBasedLabeling"_s, 4 );
        needRuleBasedLabeling = true;
      }
 
      // not use the rule based labeling if no rules with textSymbolizer
      if ( ruleCount == 0 )
      {
        needRuleBasedLabeling = false;
      }
 
      ruleElem = ruleElem.nextSiblingElement( u"Rule"_s );
    }
    featTypeStyleElem = featTypeStyleElem.nextSiblingElement( u"FeatureTypeStyle"_s );
  }
 
  if ( ruleCount == 0 )
  {
    QgsDebugMsgLevel( u"Info: No TextSymbolizer element."_s, 4 );
    return;
  }
 
  QDomElement ruleElem = mergedFeatTypeStyle.firstChildElement( u"Rule"_s );
 
  if ( needRuleBasedLabeling )
  {
    QgsDebugMsgLevel( u"Info: rule based labeling"_s, 4 );
    QgsRuleBasedLabeling::Rule *rootRule = new QgsRuleBasedLabeling::Rule( nullptr );
    while ( !ruleElem.isNull() )
    {
      QString label, description, filterExp;
      int scaleMinDenom = 0, scaleMaxDenom = 0;
      QgsPalLayerSettings settings;
 
      // retrieve the Rule element child nodes
      QDomElement childElem = ruleElem.firstChildElement();
      while ( !childElem.isNull() )
      {
        if ( childElem.localName() == "Name"_L1 )
        {
          // <se:Name> tag contains the rule identifier,
          // so prefer title tag for the label property value
          if ( label.isEmpty() )
            label = childElem.firstChild().nodeValue();
        }
        else if ( childElem.localName() == "Description"_L1 )
        {
          // <se:Description> can contains a title and an abstract
          QDomElement titleElem = childElem.firstChildElement( u"Title"_s );
          if ( !titleElem.isNull() )
          {
            label = titleElem.firstChild().nodeValue();
          }
 
          QDomElement abstractElem = childElem.firstChildElement( u"Abstract"_s );
          if ( !abstractElem.isNull() )
          {
            description = abstractElem.firstChild().nodeValue();
          }
        }
        else if ( childElem.localName() == "Abstract"_L1 )
        {
          // <sld:Abstract> (v1.0)
          description = childElem.firstChild().nodeValue();
        }
        else if ( childElem.localName() == "Title"_L1 )
        {
          // <sld:Title> (v1.0)
          label = childElem.firstChild().nodeValue();
        }
        else if ( childElem.localName() == "Filter"_L1 )
        {
          QgsExpression *filter = QgsOgcUtils::expressionFromOgcFilter( childElem );
          if ( filter )
          {
            if ( filter->hasParserError() )
            {
              QgsDebugMsgLevel( u"SLD Filter parsing error: %1"_s.arg( filter->parserErrorString() ), 3 );
            }
            else
            {
              filterExp = filter->expression();
            }
            delete filter;
          }
        }
        else if ( childElem.localName() == "MinScaleDenominator"_L1 )
        {
          bool ok;
          int v = childElem.firstChild().nodeValue().toInt( &ok );
          if ( ok )
            scaleMinDenom = v;
        }
        else if ( childElem.localName() == "MaxScaleDenominator"_L1 )
        {
          bool ok;
          int v = childElem.firstChild().nodeValue().toInt( &ok );
          if ( ok )
            scaleMaxDenom = v;
        }
        else if ( childElem.localName() == "TextSymbolizer"_L1 )
        {
          readSldTextSymbolizer( childElem, settings );
        }
 
        childElem = childElem.nextSiblingElement();
      }
 
      QgsRuleBasedLabeling::Rule *ruleLabeling = new QgsRuleBasedLabeling::Rule( new QgsPalLayerSettings( settings ), scaleMinDenom, scaleMaxDenom, filterExp, label );
      rootRule->appendChild( ruleLabeling );
 
      ruleElem = ruleElem.nextSiblingElement();
    }
 
    setLabeling( new QgsRuleBasedLabeling( rootRule ) );
    setLabelsEnabled( true );
  }
  else
  {
    QgsDebugMsgLevel( u"Info: simple labeling"_s, 4 );
    // retrieve the TextSymbolizer element child node
    QDomElement textSymbolizerElem = ruleElem.firstChildElement( u"TextSymbolizer"_s );
    QgsPalLayerSettings s;
    if ( readSldTextSymbolizer( textSymbolizerElem, s ) )
    {
      setLabeling( new QgsVectorLayerSimpleLabeling( s ) );
      setLabelsEnabled( true );
    }
  }
}
 
bool QgsVectorLayer::readSldTextSymbolizer( const QDomNode &node, QgsPalLayerSettings &settings ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( node.localName() != "TextSymbolizer"_L1 )
  {
    QgsDebugMsgLevel( u"Not a TextSymbolizer element: %1"_s.arg( node.localName() ), 3 );
    return false;
  }
  QDomElement textSymbolizerElem = node.toElement();
  // Label
  QDomElement labelElem = textSymbolizerElem.firstChildElement( u"Label"_s );
  if ( !labelElem.isNull() )
  {
    QDomElement propertyNameElem = labelElem.firstChildElement( u"PropertyName"_s );
    if ( !propertyNameElem.isNull() )
    {
      // set labeling defaults
 
      // label attribute
      QString labelAttribute = propertyNameElem.text();
      settings.fieldName = labelAttribute;
      settings.isExpression = false;
 
      int fieldIndex = mFields.lookupField( labelAttribute );
      if ( fieldIndex == -1 )
      {
        // label attribute is not in columns, check if it is an expression
        QgsExpression exp( labelAttribute );
        if ( !exp.hasEvalError() )
        {
          settings.isExpression = true;
        }
        else
        {
          QgsDebugMsgLevel( u"SLD label attribute error: %1"_s.arg( exp.evalErrorString() ), 3 );
        }
      }
    }
    else
    {
      QgsDebugMsgLevel( u"Info: PropertyName element not found."_s, 4 );
      return false;
    }
  }
  else
  {
    QgsDebugMsgLevel( u"Info: Label element not found."_s, 4 );
    return false;
  }
 
  Qgis::RenderUnit sldUnitSize = Qgis::RenderUnit::Pixels;
  if ( textSymbolizerElem.hasAttribute( u"uom"_s ) )
  {
    sldUnitSize = QgsSymbolLayerUtils::decodeSldUom( textSymbolizerElem.attribute( u"uom"_s ) );
  }
 
  QString fontFamily = u"Sans-Serif"_s;
  double fontPointSize = 10;
  Qgis::RenderUnit fontUnitSize = Qgis::RenderUnit::Points;
  int fontWeight = -1;
  bool fontItalic = false;
  bool fontUnderline = false;
 
  // Font
  QDomElement fontElem = textSymbolizerElem.firstChildElement( u"Font"_s );
  if ( !fontElem.isNull() )
  {
    QgsStringMap fontSvgParams = QgsSymbolLayerUtils::getSvgParameterList( fontElem );
    for ( QgsStringMap::iterator it = fontSvgParams.begin(); it != fontSvgParams.end(); ++it )
    {
      QgsDebugMsgLevel( u"found fontSvgParams %1: %2"_s.arg( it.key(), it.value() ), 4 );
 
      if ( it.key() == "font-family"_L1 )
      {
        fontFamily = it.value();
      }
      else if ( it.key() == "font-style"_L1 )
      {
        fontItalic = ( it.value() == "italic"_L1 ) || ( it.value() == "Italic"_L1 );
      }
      else if ( it.key() == "font-size"_L1 )
      {
        bool ok;
        double fontSize = it.value().toDouble( &ok );
        if ( ok )
        {
          fontPointSize = fontSize;
          fontUnitSize = sldUnitSize;
        }
      }
      else if ( it.key() == "font-weight"_L1 )
      {
        if ( ( it.value() == "bold"_L1 ) || ( it.value() == "Bold"_L1 ) )
          fontWeight = QFont::Bold;
      }
      else if ( it.key() == "font-underline"_L1 )
      {
        fontUnderline = ( it.value() == "underline"_L1 ) || ( it.value() == "Underline"_L1 );
      }
    }
  }
 
  QgsTextFormat format;
  QFont font( fontFamily, 1, fontWeight, fontItalic );
  font.setUnderline( fontUnderline );
  format.setFont( font );
  format.setSize( fontPointSize );
  format.setSizeUnit( fontUnitSize );
 
  // Fill
  QDomElement fillElem = textSymbolizerElem.firstChildElement( u"Fill"_s );
  QColor textColor;
  Qt::BrushStyle textBrush = Qt::SolidPattern;
  QgsSymbolLayerUtils::fillFromSld( fillElem, textBrush, textColor );
  if ( textColor.isValid() )
  {
    QgsDebugMsgLevel( u"Info: textColor %1."_s.arg( QVariant( textColor ).toString() ), 4 );
    format.setColor( textColor );
  }
 
  QgsTextBufferSettings bufferSettings;
 
  // Halo
  QDomElement haloElem = textSymbolizerElem.firstChildElement( u"Halo"_s );
  if ( !haloElem.isNull() )
  {
    bufferSettings.setEnabled( true );
    bufferSettings.setSize( 1 );
 
    QDomElement radiusElem = haloElem.firstChildElement( u"Radius"_s );
    if ( !radiusElem.isNull() )
    {
      bool ok;
      double bufferSize = radiusElem.text().toDouble( &ok );
      if ( ok )
      {
        bufferSettings.setSize( bufferSize );
        bufferSettings.setSizeUnit( sldUnitSize );
      }
    }
 
    QDomElement haloFillElem = haloElem.firstChildElement( u"Fill"_s );
    QColor bufferColor;
    Qt::BrushStyle bufferBrush = Qt::SolidPattern;
    QgsSymbolLayerUtils::fillFromSld( haloFillElem, bufferBrush, bufferColor );
    if ( bufferColor.isValid() )
    {
      QgsDebugMsgLevel( u"Info: bufferColor %1."_s.arg( QVariant( bufferColor ).toString() ), 4 );
      bufferSettings.setColor( bufferColor );
    }
  }
 
  // LabelPlacement
  QDomElement labelPlacementElem = textSymbolizerElem.firstChildElement( u"LabelPlacement"_s );
  if ( !labelPlacementElem.isNull() )
  {
    // PointPlacement
    QDomElement pointPlacementElem = labelPlacementElem.firstChildElement( u"PointPlacement"_s );
    if ( !pointPlacementElem.isNull() )
    {
      settings.placement = Qgis::LabelPlacement::OverPoint;
      if ( geometryType() == Qgis::GeometryType::Line )
      {
        settings.placement = Qgis::LabelPlacement::Horizontal;
      }
 
      QDomElement displacementElem = pointPlacementElem.firstChildElement( u"Displacement"_s );
      if ( !displacementElem.isNull() )
      {
        QDomElement displacementXElem = displacementElem.firstChildElement( u"DisplacementX"_s );
        if ( !displacementXElem.isNull() )
        {
          bool ok;
          double xOffset = displacementXElem.text().toDouble( &ok );
          if ( ok )
          {
            settings.xOffset = xOffset;
            settings.offsetUnits = sldUnitSize;
          }
        }
        QDomElement displacementYElem = displacementElem.firstChildElement( u"DisplacementY"_s );
        if ( !displacementYElem.isNull() )
        {
          bool ok;
          double yOffset = displacementYElem.text().toDouble( &ok );
          if ( ok )
          {
            settings.yOffset = yOffset;
            settings.offsetUnits = sldUnitSize;
          }
        }
      }
      QDomElement anchorPointElem = pointPlacementElem.firstChildElement( u"AnchorPoint"_s );
      if ( !anchorPointElem.isNull() )
      {
        QDomElement anchorPointXElem = anchorPointElem.firstChildElement( u"AnchorPointX"_s );
        if ( !anchorPointXElem.isNull() )
        {
          bool ok;
          double xOffset = anchorPointXElem.text().toDouble( &ok );
          if ( ok )
          {
            settings.xOffset = xOffset;
            settings.offsetUnits = sldUnitSize;
          }
        }
        QDomElement anchorPointYElem = anchorPointElem.firstChildElement( u"AnchorPointY"_s );
        if ( !anchorPointYElem.isNull() )
        {
          bool ok;
          double yOffset = anchorPointYElem.text().toDouble( &ok );
          if ( ok )
          {
            settings.yOffset = yOffset;
            settings.offsetUnits = sldUnitSize;
          }
        }
      }
 
      QDomElement rotationElem = pointPlacementElem.firstChildElement( u"Rotation"_s );
      if ( !rotationElem.isNull() )
      {
        bool ok;
        double rotation = rotationElem.text().toDouble( &ok );
        if ( ok )
        {
          settings.angleOffset = 360 - rotation;
        }
      }
    }
    else
    {
      // PointPlacement
      QDomElement linePlacementElem = labelPlacementElem.firstChildElement( u"LinePlacement"_s );
      if ( !linePlacementElem.isNull() )
      {
        settings.placement = Qgis::LabelPlacement::Line;
      }
    }
  }
 
  // read vendor options
  QgsStringMap vendorOptions;
  QDomElement vendorOptionElem = textSymbolizerElem.firstChildElement( u"VendorOption"_s );
  while ( !vendorOptionElem.isNull() && vendorOptionElem.localName() == "VendorOption"_L1 )
  {
    QString optionName = vendorOptionElem.attribute( u"name"_s );
    QString optionValue;
    if ( vendorOptionElem.firstChild().nodeType() == QDomNode::TextNode )
    {
      optionValue = vendorOptionElem.firstChild().nodeValue();
    }
    else
    {
      if ( vendorOptionElem.firstChild().nodeType() == QDomNode::ElementNode && vendorOptionElem.firstChild().localName() == "Literal"_L1 )
      {
        QgsDebugMsgLevel( vendorOptionElem.firstChild().localName(), 2 );
        optionValue = vendorOptionElem.firstChild().firstChild().nodeValue();
      }
      else
      {
        QgsDebugError( u"unexpected child of %1 named %2"_s.arg( vendorOptionElem.localName(), optionName ) );
      }
    }
 
    if ( !optionName.isEmpty() && !optionValue.isEmpty() )
    {
      vendorOptions[optionName] = optionValue;
    }
 
    vendorOptionElem = vendorOptionElem.nextSiblingElement();
  }
  if ( !vendorOptions.isEmpty() )
  {
    for ( QgsStringMap::iterator it = vendorOptions.begin(); it != vendorOptions.end(); ++it )
    {
      if ( it.key() == "underlineText"_L1 && it.value() == "true"_L1 )
      {
        font.setUnderline( true );
        format.setFont( font );
      }
      else if ( it.key() == "strikethroughText"_L1 && it.value() == "true"_L1 )
      {
        font.setStrikeOut( true );
        format.setFont( font );
      }
      else if ( it.key() == "maxDisplacement"_L1 )
      {
        settings.placement = Qgis::LabelPlacement::AroundPoint;
      }
      else if ( it.key() == "followLine"_L1 && it.value() == "true"_L1 )
      {
        if ( geometryType() == Qgis::GeometryType::Polygon )
        {
          settings.placement = Qgis::LabelPlacement::PerimeterCurved;
        }
        else
        {
          settings.placement = Qgis::LabelPlacement::Curved;
        }
      }
      else if ( it.key() == "maxAngleDelta"_L1 )
      {
        bool ok;
        double angle = it.value().toDouble( &ok );
        if ( ok )
        {
          settings.maxCurvedCharAngleIn = angle;
          settings.maxCurvedCharAngleOut = angle;
        }
      }
      // miscellaneous options
      else if ( it.key() == "conflictResolution"_L1 && it.value() == "false"_L1 )
      {
        settings.placementSettings().setOverlapHandling( Qgis::LabelOverlapHandling::AllowOverlapIfRequired );
      }
      else if ( it.key() == "forceLeftToRight"_L1 && it.value() == "false"_L1 )
      {
        settings.upsidedownLabels = Qgis::UpsideDownLabelHandling::AlwaysAllowUpsideDown;
      }
      else if ( it.key() == "group"_L1 && it.value() == "yes"_L1 )
      {
        settings.lineSettings().setMergeLines( true );
      }
      else if ( it.key() == "labelAllGroup"_L1 && it.value() == "true"_L1 )
      {
        settings.lineSettings().setMergeLines( true );
      }
    }
  }
 
  format.setBuffer( bufferSettings );
  settings.setFormat( format );
  return true;
}
 
QgsEditFormConfig QgsVectorLayer::editFormConfig() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return mEditFormConfig;
}
 
void QgsVectorLayer::setEditFormConfig( const QgsEditFormConfig &editFormConfig )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( mEditFormConfig == editFormConfig )
    return;
 
  mEditFormConfig = editFormConfig;
  mEditFormConfig.onRelationsLoaded();
  emit editFormConfigChanged();
}
 
QgsAttributeTableConfig QgsVectorLayer::attributeTableConfig() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QgsAttributeTableConfig config = mAttributeTableConfig;
 
  if ( config.isEmpty() )
    config.update( fields() );
 
  return config;
}
 
void QgsVectorLayer::setAttributeTableConfig( const QgsAttributeTableConfig &attributeTableConfig )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( mAttributeTableConfig != attributeTableConfig )
  {
    mAttributeTableConfig = attributeTableConfig;
    emit configChanged();
  }
}
 
QgsExpressionContext QgsVectorLayer::createExpressionContext() const
{
  // called in a non-thread-safe way in some cases when calculating aggregates in a different thread
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS_NON_FATAL
 
  return QgsExpressionContext( QgsExpressionContextUtils::globalProjectLayerScopes( this ) );
}
 
QgsExpressionContextScope *QgsVectorLayer::createExpressionContextScope() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return QgsExpressionContextUtils::layerScope( this );
}
 
void QgsVectorLayer::setDiagramLayerSettings( const QgsDiagramLayerSettings &s )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( !mDiagramLayerSettings )
    mDiagramLayerSettings = new QgsDiagramLayerSettings();
  *mDiagramLayerSettings = s;
}
 
QString QgsVectorLayer::htmlMetadata() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QgsLayerMetadataFormatter htmlFormatter( metadata() );
  QString myMetadata = u"<html><head></head>\n<body>\n"_s;
 
  myMetadata += generalHtmlMetadata();
 
  // Begin Provider section
  myMetadata += u"<h1>"_s + tr( "Information from provider" ) + u"</h1>\n<hr>\n"_s;
  myMetadata += "<table class=\"list-view\">\n"_L1;
 
  // storage type
  if ( !storageType().isEmpty() )
  {
    myMetadata += u"<tr><td class=\"highlight\">"_s + tr( "Storage" ) + u"</td><td>"_s + storageType() + u"</td></tr>\n"_s;
  }
 
  // comment
  if ( !dataComment().isEmpty() )
  {
    myMetadata += u"<tr><td class=\"highlight\">"_s + tr( "Comment" ) + u"</td><td>"_s + dataComment() + u"</td></tr>\n"_s;
  }
 
  // encoding
  if ( const QgsVectorDataProvider *provider = dataProvider() )
  {
    myMetadata += u"<tr><td class=\"highlight\">"_s + tr( "Encoding" ) + u"</td><td>"_s + provider->encoding() + u"</td></tr>\n"_s;
    myMetadata += provider->htmlMetadata();
  }
 
  if ( isSpatial() )
  {
    // geom type
    Qgis::GeometryType type = geometryType();
    if ( static_cast<int>( type ) < 0 || static_cast< int >( type ) > static_cast< int >( Qgis::GeometryType::Null ) )
    {
      QgsDebugMsgLevel( u"Invalid vector type"_s, 2 );
    }
    else
    {
      QString typeString( u"%1 (%2)"_s.arg( QgsWkbTypes::geometryDisplayString( geometryType() ), QgsWkbTypes::displayString( wkbType() ) ) );
      myMetadata += u"<tr><td class=\"highlight\">"_s + tr( "Geometry type" ) + u"</td><td>"_s + typeString + u"</td></tr>\n"_s;
    }
 
    // geom column name
    if ( const QgsVectorDataProvider *provider = dataProvider(); provider && !provider->geometryColumnName().isEmpty() )
    {
      myMetadata += u"<tr><td class=\"highlight\">"_s + tr( "Geometry column" ) + u"</td><td>"_s + provider->geometryColumnName() + u"</td></tr>\n"_s;
    }
 
    // Extent
    // Try to display extent 3D by default. If empty (probably because the data is 2D), fallback to the 2D version
    const QgsBox3D extentBox3D = extent3D();
    const QString extentAsStr = !extentBox3D.isEmpty() ? extentBox3D.toString() : extent().toString();
    myMetadata += u"<tr><td class=\"highlight\">"_s + tr( "Extent" ) + u"</td><td>"_s + extentAsStr + u"</td></tr>\n"_s;
  }
 
  // feature count
  QLocale locale = QLocale();
  locale.setNumberOptions( locale.numberOptions() &= ~QLocale::NumberOption::OmitGroupSeparator );
  myMetadata += u"<tr><td class=\"highlight\">"_s
                + tr( "Feature count" )
                + u"</td><td>"_s
                + ( featureCount() == -1 ? tr( "unknown" ) : locale.toString( static_cast<qlonglong>( featureCount() ) ) )
                + u"</td></tr>\n"_s;
 
  // End Provider section
  myMetadata += "</table>\n<br><br>"_L1;
 
  if ( isSpatial() )
  {
    // CRS
    myMetadata += crsHtmlMetadata();
  }
 
  // identification section
  myMetadata += u"<h1>"_s + tr( "Identification" ) + u"</h1>\n<hr>\n"_s;
  myMetadata += htmlFormatter.identificationSectionHtml();
  myMetadata += "<br><br>\n"_L1;
 
  // extent section
  myMetadata += u"<h1>"_s + tr( "Extent" ) + u"</h1>\n<hr>\n"_s;
  myMetadata += htmlFormatter.extentSectionHtml( isSpatial() );
  myMetadata += "<br><br>\n"_L1;
 
  // Start the Access section
  myMetadata += u"<h1>"_s + tr( "Access" ) + u"</h1>\n<hr>\n"_s;
  myMetadata += htmlFormatter.accessSectionHtml();
  myMetadata += "<br><br>\n"_L1;
 
  // Fields section
  myMetadata += u"<h1>"_s + tr( "Fields" ) + u"</h1>\n<hr>\n<table class=\"list-view\">\n"_s;
 
  // primary key
  QgsAttributeList pkAttrList = primaryKeyAttributes();
  if ( !pkAttrList.isEmpty() )
  {
    myMetadata += u"<tr><td class=\"highlight\">"_s + tr( "Primary key attributes" ) + u"</td><td>"_s;
    const auto constPkAttrList = pkAttrList;
    for ( int idx : constPkAttrList )
    {
      myMetadata += fields().at( idx ).name() + ' ';
    }
    myMetadata += "</td></tr>\n"_L1;
  }
 
  const QgsFields myFields = fields();
 
  // count fields
  myMetadata += u"<tr><td class=\"highlight\">"_s + tr( "Count" ) + u"</td><td>"_s + QString::number( myFields.size() ) + u"</td></tr>\n"_s;
 
  myMetadata += "</table>\n<br><table width=\"100%\" class=\"tabular-view\">\n"_L1;
  myMetadata += "<tr><th>"_L1 + tr( "Field" ) + "</th><th>"_L1 + tr( "Type" ) + "</th><th>"_L1 + tr( "Length" ) + "</th><th>"_L1 + tr( "Precision" ) + "</th><th>"_L1 + tr( "Comment" ) + "</th></tr>\n"_L1;
 
  for ( int i = 0; i < myFields.size(); ++i )
  {
    QgsField myField = myFields.at( i );
    QString rowClass;
    if ( i % 2 )
      rowClass = u"class=\"odd-row\""_s;
    myMetadata += "<tr "_L1
                  + rowClass
                  + "><td>"_L1
                  + myField.displayNameWithAlias()
                  + "</td><td>"_L1
                  + myField.typeName()
                  + "</td><td>"_L1
                  + QString::number( myField.length() )
                  + "</td><td>"_L1
                  + QString::number( myField.precision() )
                  + "</td><td>"_L1
                  + myField.comment()
                  + "</td></tr>\n"_L1;
  }
 
  //close field list
  myMetadata += "</table>\n<br><br>"_L1;
 
  // Start the contacts section
  myMetadata += u"<h1>"_s + tr( "Contacts" ) + u"</h1>\n<hr>\n"_s;
  myMetadata += htmlFormatter.contactsSectionHtml();
  myMetadata += "<br><br>\n"_L1;
 
  // Start the links section
  myMetadata += u"<h1>"_s + tr( "Links" ) + u"</h1>\n<hr>\n"_s;
  myMetadata += htmlFormatter.linksSectionHtml();
  myMetadata += "<br><br>\n"_L1;
 
  // Start the history section
  myMetadata += u"<h1>"_s + tr( "History" ) + u"</h1>\n<hr>\n"_s;
  myMetadata += htmlFormatter.historySectionHtml();
  myMetadata += "<br><br>\n"_L1;
 
  myMetadata += customPropertyHtmlMetadata();
 
  myMetadata += "\n</body>\n</html>\n"_L1;
  return myMetadata;
}
 
void QgsVectorLayer::invalidateSymbolCountedFlag()
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  mSymbolFeatureCounted = false;
}
 
void QgsVectorLayer::onFeatureCounterCompleted()
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  onSymbolsCounted();
  mFeatureCounter = nullptr;
}
 
void QgsVectorLayer::onFeatureCounterTerminated()
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  mFeatureCounter = nullptr;
}
 
void QgsVectorLayer::onJoinedFieldsChanged()
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  // some of the fields of joined layers have changed -> we need to update this layer's fields too
  updateFields();
}
 
void QgsVectorLayer::onFeatureAdded( QgsFeatureId fid )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  updateExtents();
 
  emit featureAdded( fid );
}
 
void QgsVectorLayer::onFeatureDeleted( QgsFeatureId fid )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  updateExtents();
 
  if ( mEditCommandActive || mCommitChangesActive )
  {
    mDeletedFids << fid;
  }
  else
  {
    mSelectedFeatureIds.remove( fid );
    emit featuresDeleted( QgsFeatureIds() << fid );
  }
 
  emit featureDeleted( fid );
}
 
void QgsVectorLayer::onRelationsLoaded()
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  mEditFormConfig.onRelationsLoaded();
}
 
void QgsVectorLayer::onSymbolsCounted()
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( mFeatureCounter )
  {
    mSymbolFeatureCounted = true;
    mSymbolFeatureCountMap = mFeatureCounter->symbolFeatureCountMap();
    mSymbolFeatureIdMap = mFeatureCounter->symbolFeatureIdMap();
    emit symbolFeatureCountMapChanged();
  }
}
 
QList<QgsRelation> QgsVectorLayer::referencingRelations( int idx ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( QgsProject *p = project() )
    return p->relationManager()->referencingRelations( this, idx );
  else
    return {};
}
 
QList<QgsWeakRelation> QgsVectorLayer::weakRelations() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return mWeakRelations;
}
 
void QgsVectorLayer::setWeakRelations( const QList<QgsWeakRelation> &relations )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  mWeakRelations = relations;
}
 
bool QgsVectorLayer::loadAuxiliaryLayer( const QgsAuxiliaryStorage &storage, const QString &key )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  bool rc = false;
 
  QString joinKey = mAuxiliaryLayerKey;
  if ( !key.isEmpty() )
    joinKey = key;
 
  if ( storage.isValid() && !joinKey.isEmpty() )
  {
    QgsAuxiliaryLayer *alayer = nullptr;
 
    int idx = fields().lookupField( joinKey );
 
    if ( idx >= 0 )
    {
      alayer = storage.createAuxiliaryLayer( fields().field( idx ), this );
 
      if ( alayer )
      {
        setAuxiliaryLayer( alayer );
        rc = true;
      }
    }
  }
 
  return rc;
}
 
void QgsVectorLayer::setAuxiliaryLayer( QgsAuxiliaryLayer *alayer )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  mAuxiliaryLayerKey.clear();
 
  if ( mAuxiliaryLayer )
    removeJoin( mAuxiliaryLayer->id() );
 
  if ( alayer )
  {
    addJoin( alayer->joinInfo() );
 
    if ( !alayer->isEditable() )
      alayer->startEditing();
 
    mAuxiliaryLayerKey = alayer->joinInfo().targetFieldName();
  }
 
  mAuxiliaryLayer.reset( alayer );
  if ( mAuxiliaryLayer )
    mAuxiliaryLayer->setParent( this );
  updateFields();
}
 
const QgsAuxiliaryLayer *QgsVectorLayer::auxiliaryLayer() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return mAuxiliaryLayer.get();
}
 
QgsAuxiliaryLayer *QgsVectorLayer::auxiliaryLayer()
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return mAuxiliaryLayer.get();
}
 
QSet<QgsMapLayerDependency> QgsVectorLayer::dependencies() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( mDataProvider )
    return mDataProvider->dependencies() + mDependencies;
  return mDependencies;
}
 
void QgsVectorLayer::emitDataChanged()
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( mDataChangedFired )
    return;
 
  // If we are asked to fire dataChanged from a layer we depend on,
  // be sure that this layer is not in the process of committing its changes, because
  // we will be asked to fire dataChanged at the end of his commit, and we don't
  // want to fire this signal more than necessary.
  if ( QgsVectorLayer *layerWeDependUpon = qobject_cast<QgsVectorLayer *>( sender() ); layerWeDependUpon && layerWeDependUpon->mCommitChangesActive )
    return;
 
  updateExtents(); // reset cached extent to reflect data changes
 
  mDataChangedFired = true;
  emit dataChanged();
  mDataChangedFired = false;
}
 
void QgsVectorLayer::onDependencyAfterCommitChanges()
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( mDataProvider && mDataProvider->capabilities().testFlag( Qgis::VectorProviderCapability::CacheData ) )
    mDataProvider->reloadData();
  else
    emitDataChanged();
}
 
bool QgsVectorLayer::setDependencies( const QSet<QgsMapLayerDependency> &oDeps )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QSet<QgsMapLayerDependency> deps;
  const auto constODeps = oDeps;
  for ( const QgsMapLayerDependency &dep : constODeps )
  {
    if ( dep.origin() == QgsMapLayerDependency::FromUser )
      deps << dep;
  }
 
  QSet<QgsMapLayerDependency> toAdd = deps - dependencies();
 
  // disconnect layers that are not present in the list of dependencies anymore
  if ( QgsProject *p = project() )
  {
    for ( const QgsMapLayerDependency &dep : std::as_const( mDependencies ) )
    {
      QgsVectorLayer *lyr = static_cast<QgsVectorLayer *>( p->mapLayer( dep.layerId() ) );
      if ( !lyr )
        continue;
      disconnect( lyr, &QgsVectorLayer::featureAdded, this, &QgsVectorLayer::emitDataChanged );
      disconnect( lyr, &QgsVectorLayer::featureDeleted, this, &QgsVectorLayer::emitDataChanged );
      disconnect( lyr, &QgsVectorLayer::geometryChanged, this, &QgsVectorLayer::emitDataChanged );
      disconnect( lyr, &QgsVectorLayer::dataChanged, this, &QgsVectorLayer::emitDataChanged );
      disconnect( lyr, &QgsVectorLayer::repaintRequested, this, &QgsVectorLayer::triggerRepaint );
      disconnect( lyr, &QgsVectorLayer::afterCommitChanges, this, &QgsVectorLayer::onDependencyAfterCommitChanges );
    }
  }
 
  // assign new dependencies
  if ( mDataProvider )
    mDependencies = mDataProvider->dependencies() + deps;
  else
    mDependencies = deps;
  emit dependenciesChanged();
 
  // connect to new layers
  if ( QgsProject *p = project() )
  {
    for ( const QgsMapLayerDependency &dep : std::as_const( mDependencies ) )
    {
      QgsVectorLayer *lyr = static_cast<QgsVectorLayer *>( p->mapLayer( dep.layerId() ) );
      if ( !lyr )
        continue;
      connect( lyr, &QgsVectorLayer::featureAdded, this, &QgsVectorLayer::emitDataChanged );
      connect( lyr, &QgsVectorLayer::featureDeleted, this, &QgsVectorLayer::emitDataChanged );
      connect( lyr, &QgsVectorLayer::geometryChanged, this, &QgsVectorLayer::emitDataChanged );
      connect( lyr, &QgsVectorLayer::dataChanged, this, &QgsVectorLayer::emitDataChanged );
      connect( lyr, &QgsVectorLayer::repaintRequested, this, &QgsVectorLayer::triggerRepaint );
      connect( lyr, &QgsVectorLayer::afterCommitChanges, this, &QgsVectorLayer::onDependencyAfterCommitChanges );
    }
  }
 
  // if new layers are present, emit a data change
  if ( !toAdd.isEmpty() )
    emitDataChanged();
 
  return true;
}
 
QgsFieldConstraints::Constraints QgsVectorLayer::fieldConstraints( int fieldIndex ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( fieldIndex < 0 || fieldIndex >= mFields.count() || !mDataProvider )
    return QgsFieldConstraints::Constraints();
 
  QgsFieldConstraints::Constraints constraints = mFields.at( fieldIndex ).constraints().constraints();
 
  // make sure provider constraints are always present!
  if ( mFields.fieldOrigin( fieldIndex ) == Qgis::FieldOrigin::Provider )
  {
    constraints |= mDataProvider->fieldConstraints( mFields.fieldOriginIndex( fieldIndex ) );
  }
 
  return constraints;
}
 
QMap< QgsFieldConstraints::Constraint, QgsFieldConstraints::ConstraintStrength> QgsVectorLayer::fieldConstraintsAndStrength( int fieldIndex ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QMap< QgsFieldConstraints::Constraint, QgsFieldConstraints::ConstraintStrength > m;
 
  if ( fieldIndex < 0 || fieldIndex >= mFields.count() )
    return m;
 
  QString name = mFields.at( fieldIndex ).name();
 
  QMap< QPair< QString, QgsFieldConstraints::Constraint >, QgsFieldConstraints::ConstraintStrength >::const_iterator conIt = mFieldConstraintStrength.constBegin();
  for ( ; conIt != mFieldConstraintStrength.constEnd(); ++conIt )
  {
    if ( conIt.key().first == name )
    {
      m[conIt.key().second] = mFieldConstraintStrength.value( conIt.key() );
    }
  }
 
  return m;
}
 
void QgsVectorLayer::setFieldConstraint( int index, QgsFieldConstraints::Constraint constraint, QgsFieldConstraints::ConstraintStrength strength )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( index < 0 || index >= mFields.count() )
    return;
 
  QString name = mFields.at( index ).name();
 
  // add constraint to existing constraints
  QgsFieldConstraints::Constraints constraints = mFieldConstraints.value( name, QgsFieldConstraints::Constraints() );
  constraints |= constraint;
  mFieldConstraints.insert( name, constraints );
 
  mFieldConstraintStrength.insert( qMakePair( name, constraint ), strength );
 
  updateFields();
}
 
void QgsVectorLayer::removeFieldConstraint( int index, QgsFieldConstraints::Constraint constraint )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( index < 0 || index >= mFields.count() )
    return;
 
  QString name = mFields.at( index ).name();
 
  // remove constraint from existing constraints
  QgsFieldConstraints::Constraints constraints = mFieldConstraints.value( name, QgsFieldConstraints::Constraints() );
  constraints &= ~constraint;
  mFieldConstraints.insert( name, constraints );
 
  mFieldConstraintStrength.remove( qMakePair( name, constraint ) );
 
  updateFields();
}
 
QString QgsVectorLayer::constraintExpression( int index ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( index < 0 || index >= mFields.count() )
    return QString();
 
  return mFields.at( index ).constraints().constraintExpression();
}
 
QString QgsVectorLayer::constraintDescription( int index ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( index < 0 || index >= mFields.count() )
    return QString();
 
  return mFields.at( index ).constraints().constraintDescription();
}
 
void QgsVectorLayer::setConstraintExpression( int index, const QString &expression, const QString &description )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( index < 0 || index >= mFields.count() )
    return;
 
  if ( expression.isEmpty() )
  {
    mFieldConstraintExpressions.remove( mFields.at( index ).name() );
  }
  else
  {
    mFieldConstraintExpressions.insert( mFields.at( index ).name(), qMakePair( expression, description ) );
  }
  updateFields();
}
 
void QgsVectorLayer::setFieldConfigurationFlags( int index, Qgis::FieldConfigurationFlags flags )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( index < 0 || index >= mFields.count() )
    return;
 
  mFieldConfigurationFlags.insert( mFields.at( index ).name(), flags );
  updateFields();
}
 
void QgsVectorLayer::setFieldConfigurationFlag( int index, Qgis::FieldConfigurationFlag flag, bool active )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( index < 0 || index >= mFields.count() )
    return;
  Qgis::FieldConfigurationFlags flags = mFields.at( index ).configurationFlags();
  flags.setFlag( flag, active );
  setFieldConfigurationFlags( index, flags );
}
 
Qgis::FieldConfigurationFlags QgsVectorLayer::fieldConfigurationFlags( int index ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( index < 0 || index >= mFields.count() )
    return Qgis::FieldConfigurationFlag::NoFlag;
 
  return mFields.at( index ).configurationFlags();
}
 
void QgsVectorLayer::setEditorWidgetSetup( int index, const QgsEditorWidgetSetup &setup )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( index < 0 || index >= mFields.count() )
    return;
 
  if ( setup.isNull() )
    mFieldWidgetSetups.remove( mFields.at( index ).name() );
  else
    mFieldWidgetSetups.insert( mFields.at( index ).name(), setup );
  updateFields();
}
 
QgsEditorWidgetSetup QgsVectorLayer::editorWidgetSetup( int index ) const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( index < 0 || index >= mFields.count() )
    return QgsEditorWidgetSetup();
 
  return mFields.at( index ).editorWidgetSetup();
}
 
QgsAbstractVectorLayerLabeling *QgsVectorLayer::readLabelingFromCustomProperties()
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QgsAbstractVectorLayerLabeling *labeling = nullptr;
  if ( customProperty( u"labeling"_s ).toString() == "pal"_L1 )
  {
    if ( customProperty( u"labeling/enabled"_s, QVariant( false ) ).toBool() )
    {
      // try to load from custom properties
      QgsPalLayerSettings settings;
      settings.readFromLayerCustomProperties( this );
      labeling = new QgsVectorLayerSimpleLabeling( settings );
    }
 
    // also clear old-style labeling config
    removeCustomProperty( u"labeling"_s );
    const auto constCustomPropertyKeys = customPropertyKeys();
    for ( const QString &key : constCustomPropertyKeys )
    {
      if ( key.startsWith( "labeling/"_L1 ) )
        removeCustomProperty( key );
    }
  }
 
  return labeling;
}
 
bool QgsVectorLayer::allowCommit() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return mAllowCommit;
}
 
void QgsVectorLayer::setAllowCommit( bool allowCommit )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  if ( mAllowCommit == allowCommit )
    return;
 
  mAllowCommit = allowCommit;
  emit allowCommitChanged();
}
 
QgsGeometryOptions *QgsVectorLayer::geometryOptions() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return mGeometryOptions.get();
}
 
void QgsVectorLayer::setReadExtentFromXml( bool readExtentFromXml )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  mReadExtentFromXml = readExtentFromXml;
}
 
bool QgsVectorLayer::readExtentFromXml() const
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  return mReadExtentFromXml;
}
 
void QgsVectorLayer::onDirtyTransaction( const QString &sql, const QString &name )
{
  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
 
  QgsTransaction *tr = dataProvider()->transaction();
  if ( tr && mEditBuffer )
  {
    qobject_cast<QgsVectorLayerEditPassthrough *>( mEditBuffer )->update( tr, sql, name );
  }
}
 
QList<QgsVectorLayer *> QgsVectorLayer::DeleteContext::handledLayers( bool includeAuxiliaryLayers ) const
{
  QList<QgsVectorLayer *> layers;
  QMap<QgsVectorLayer *, QgsFeatureIds>::const_iterator i;
  for ( i = mHandledFeatures.begin(); i != mHandledFeatures.end(); ++i )
  {
    if ( includeAuxiliaryLayers || !qobject_cast< QgsAuxiliaryLayer * >( i.key() ) )
      layers.append( i.key() );
  }
  return layers;
}
 
QgsFeatureIds QgsVectorLayer::DeleteContext::handledFeatures( QgsVectorLayer *layer ) const
{
  return mHandledFeatures[layer];
}