QGIS API Documentation  2.99.0-Master (19b062c)
Classes | Public Member Functions | Protected Member Functions | Protected Attributes | List of all members
QgsVectorLayerFeatureIterator Class Reference

#include <qgsvectorlayerfeatureiterator.h>

Inheritance diagram for QgsVectorLayerFeatureIterator:
Inheritance graph
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Classes

struct  FetchJoinInfo
 Join information prepared for fast attribute id mapping in QgsVectorLayerJoinBuffer::updateFeatureAttributes(). More...
 

Public Member Functions

 QgsVectorLayerFeatureIterator (QgsVectorLayerFeatureSource *source, bool ownSource, const QgsFeatureRequest &request)
 
 ~QgsVectorLayerFeatureIterator ()
 
virtual bool close () override
 end of iterating: free the resources / lock More...
 
virtual bool isValid () const override
 Returns if this iterator is valid. More...
 
virtual bool rewind () override
 reset the iterator to the starting position More...
 
virtual void setInterruptionChecker (QgsInterruptionChecker *interruptionChecker) override
 Attach an object that can be queried regularly by the iterator to check if it must stopped. More...
 
- Public Member Functions inherited from QgsAbstractFeatureIteratorFromSource< QgsVectorLayerFeatureSource >
 QgsAbstractFeatureIteratorFromSource (QgsVectorLayerFeatureSource *source, bool ownSource, const QgsFeatureRequest &request)
 
 ~QgsAbstractFeatureIteratorFromSource ()
 
- Public Member Functions inherited from QgsAbstractFeatureIterator
 QgsAbstractFeatureIterator (const QgsFeatureRequest &request)
 base class constructor - stores the iteration parameters More...
 
virtual ~QgsAbstractFeatureIterator ()=default
 destructor makes sure that the iterator is closed properly More...
 
CompileStatus compileStatus () const
 Returns the status of expression compilation for filter expression requests. More...
 
virtual bool nextFeature (QgsFeature &f)
 fetch next feature, return true on success More...
 

Protected Member Functions

void addExpressionAttribute (QgsFeature &f, int attrIndex)
 Adds an expression based attribute to a feature. More...
 
void addJoinedAttributes (QgsFeature &f)
 
void addVirtualAttributes (QgsFeature &f)
 Adds attributes that don't source from the provider but are added inside QGIS Includes. More...
 
virtual bool fetchFeature (QgsFeature &feature) override
 fetch next feature, return true on success More...
 
bool fetchNextAddedFeature (QgsFeature &f)
 
bool fetchNextChangedAttributeFeature (QgsFeature &f)
 
bool fetchNextChangedGeomFeature (QgsFeature &f)
 
bool nextFeatureFid (QgsFeature &f)
 
virtual bool nextFeatureFilterExpression (QgsFeature &f) override
 Overrides default method as we only need to filter features in the edit buffer while for others filtering is left to the provider implementation. More...
 
void prepareExpression (int fieldIdx)
 
void prepareField (int fieldIdx)
 
void prepareFields ()
 
void prepareJoin (int fieldIdx)
 
virtual bool prepareSimplification (const QgsSimplifyMethod &simplifyMethod) override
 Setup the simplification of geometries to fetch using the specified simplify method. More...
 
void rewindEditBuffer ()
 
void updateChangedAttributes (QgsFeature &f)
 Update feature with uncommitted attribute updates. More...
 
void updateFeatureGeometry (QgsFeature &f)
 Update feature with uncommitted geometry updates. More...
 
void useAddedFeature (const QgsFeature &src, QgsFeature &f)
 
void useChangedAttributeFeature (QgsFeatureId fid, const QgsGeometry &geom, QgsFeature &f)
 
- Protected Member Functions inherited from QgsAbstractFeatureIteratorFromSource< QgsVectorLayerFeatureSource >
void iteratorClosed ()
 to be called by from subclass in close() More...
 
- Protected Member Functions inherited from QgsAbstractFeatureIterator
void deref ()
 Remove reference, delete if refs == 0. More...
 
QgsRectangle filterRectToSourceCrs (const QgsCoordinateTransform &transform) const
 Returns a rectangle representing the original request's QgsFeatureRequest::filterRect(). More...
 
void geometryToDestinationCrs (QgsFeature &feature, const QgsCoordinateTransform &transform) const
 Transforms feature's geometry according to the specified coordinate transform. More...
 
virtual bool nextFeatureFilterFids (QgsFeature &f)
 By default, the iterator will fetch all features and check if the id is in the request. More...
 
void ref ()
 Add reference. More...
 

Protected Attributes

QgsFeatureIterator mChangedFeaturesIterator
 
QgsFeatureRequest mChangedFeaturesRequest
 
QMap< int, QgsExpression * > mExpressionFieldInfo
 
QgsFeatureMap::ConstIterator mFetchAddedFeaturesIt
 
QgsGeometryMap::ConstIterator mFetchChangedGeomIt
 
QSet< QgsFeatureIdmFetchConsidered
 
bool mFetchedFid
 
QMap< const QgsVectorLayerJoinInfo *, QgsVectorLayerFeatureIterator::FetchJoinInfomFetchJoinInfo
 Information about joins used in the current select() statement. More...
 
QgsRectangle mFilterRect
 
bool mHasVirtualAttributes
 
QgsFeatureIterator mProviderIterator
 
QgsFeatureRequest mProviderRequest
 
QgsCoordinateTransform mTransform
 
- Protected Attributes inherited from QgsAbstractFeatureIteratorFromSource< QgsVectorLayerFeatureSource >
bool mOwnSource
 
QgsVectorLayerFeatureSourcemSource
 
- Protected Attributes inherited from QgsAbstractFeatureIterator
bool mClosed = false
 Set to true, as soon as the iterator is closed. More...
 
CompileStatus mCompileStatus = NoCompilation
 Status of compilation of filter expression. More...
 
long mFetchedCount = 0
 Number of features already fetched by iterator. More...
 
QgsFeatureRequest mRequest
 A copy of the feature request. More...
 
bool mValid = true
 An invalid state of a feature iterator indicates that there was a problem with even getting it up and running. More...
 
bool mZombie = false
 A feature iterator may be closed already but still be serving features from the cache. More...
 
int refs = 0
 reference counting (to allow seamless copying of QgsFeatureIterator instances) TODO QGIS3: make this private More...
 

Additional Inherited Members

- Public Types inherited from QgsAbstractFeatureIterator
enum  CompileStatus { NoCompilation, PartiallyCompiled, Compiled }
 Status of expression compilation for filter expression requests. More...
 

Detailed Description

Definition at line 109 of file qgsvectorlayerfeatureiterator.h.

Constructor & Destructor Documentation

◆ QgsVectorLayerFeatureIterator()

QgsVectorLayerFeatureIterator::QgsVectorLayerFeatureIterator ( QgsVectorLayerFeatureSource source,
bool  ownSource,
const QgsFeatureRequest request 
)

Definition at line 111 of file qgsvectorlayerfeatureiterator.cpp.

◆ ~QgsVectorLayerFeatureIterator()

QgsVectorLayerFeatureIterator::~QgsVectorLayerFeatureIterator ( )

Definition at line 266 of file qgsvectorlayerfeatureiterator.cpp.

Member Function Documentation

◆ addExpressionAttribute()

void QgsVectorLayerFeatureIterator::addExpressionAttribute ( QgsFeature f,
int  attrIndex 
)
protected

Adds an expression based attribute to a feature.

Parameters
ffeature
attrIndexattribute index
Since
QGIS 2.14
Note
not available in Python bindings

Definition at line 870 of file qgsvectorlayerfeatureiterator.cpp.

◆ addJoinedAttributes()

void QgsVectorLayerFeatureIterator::addJoinedAttributes ( QgsFeature f)
protected
Note
not available in Python bindings

Definition at line 813 of file qgsvectorlayerfeatureiterator.cpp.

◆ addVirtualAttributes()

void QgsVectorLayerFeatureIterator::addVirtualAttributes ( QgsFeature f)
protected

Adds attributes that don't source from the provider but are added inside QGIS Includes.

  • Joined fields
  • Expression fields
Parameters
fThe feature will be modified
Note
not available in Python bindings

Definition at line 830 of file qgsvectorlayerfeatureiterator.cpp.

◆ close()

bool QgsVectorLayerFeatureIterator::close ( )
overridevirtual

end of iterating: free the resources / lock

Implements QgsAbstractFeatureIterator.

Definition at line 392 of file qgsvectorlayerfeatureiterator.cpp.

◆ fetchFeature()

bool QgsVectorLayerFeatureIterator::fetchFeature ( QgsFeature feature)
overrideprotectedvirtual

fetch next feature, return true on success

Implements QgsAbstractFeatureIterator.

Definition at line 275 of file qgsvectorlayerfeatureiterator.cpp.

◆ fetchNextAddedFeature()

bool QgsVectorLayerFeatureIterator::fetchNextAddedFeature ( QgsFeature f)
protected
Note
not available in Python bindings

Definition at line 416 of file qgsvectorlayerfeatureiterator.cpp.

◆ fetchNextChangedAttributeFeature()

bool QgsVectorLayerFeatureIterator::fetchNextChangedAttributeFeature ( QgsFeature f)
protected
Note
not available in Python bindings

Definition at line 499 of file qgsvectorlayerfeatureiterator.cpp.

◆ fetchNextChangedGeomFeature()

bool QgsVectorLayerFeatureIterator::fetchNextChangedGeomFeature ( QgsFeature f)
protected
Note
not available in Python bindings

Definition at line 460 of file qgsvectorlayerfeatureiterator.cpp.

◆ isValid()

bool QgsVectorLayerFeatureIterator::isValid ( ) const
overridevirtual

Returns if this iterator is valid.

An invalid feature iterator is not able to provide a reliable source for data. If an iterator is invalid, either give up or try to send the request again (preferably after a timeout to give the system some time to stay responsive).

If you want to check if the iterator successfully completed, better use QgsFeatureIterator::isClosed().

Since
QGIS 3.0

Reimplemented from QgsAbstractFeatureIterator.

Definition at line 411 of file qgsvectorlayerfeatureiterator.cpp.

◆ nextFeatureFid()

bool QgsVectorLayerFeatureIterator::nextFeatureFid ( QgsFeature f)
protected
Note
not available in Python bindings

Definition at line 998 of file qgsvectorlayerfeatureiterator.cpp.

◆ nextFeatureFilterExpression()

virtual bool QgsVectorLayerFeatureIterator::nextFeatureFilterExpression ( QgsFeature f)
inlineoverrideprotectedvirtual

Overrides default method as we only need to filter features in the edit buffer while for others filtering is left to the provider implementation.

Reimplemented from QgsAbstractFeatureIterator.

Definition at line 152 of file qgsvectorlayerfeatureiterator.h.

◆ prepareExpression()

void QgsVectorLayerFeatureIterator::prepareExpression ( int  fieldIdx)
protected
Note
not available in Python bindings

Definition at line 610 of file qgsvectorlayerfeatureiterator.cpp.

◆ prepareField()

void QgsVectorLayerFeatureIterator::prepareField ( int  fieldIdx)
protected
Note
not available in Python bindings

Definition at line 791 of file qgsvectorlayerfeatureiterator.cpp.

◆ prepareFields()

void QgsVectorLayerFeatureIterator::prepareFields ( )
protected
Note
not available in Python bindings

Definition at line 654 of file qgsvectorlayerfeatureiterator.cpp.

◆ prepareJoin()

void QgsVectorLayerFeatureIterator::prepareJoin ( int  fieldIdx)
protected
Note
not available in Python bindings

Definition at line 571 of file qgsvectorlayerfeatureiterator.cpp.

◆ prepareSimplification()

bool QgsVectorLayerFeatureIterator::prepareSimplification ( const QgsSimplifyMethod simplifyMethod)
overrideprotectedvirtual

Setup the simplification of geometries to fetch using the specified simplify method.

Reimplemented from QgsAbstractFeatureIterator.

Definition at line 886 of file qgsvectorlayerfeatureiterator.cpp.

◆ rewind()

bool QgsVectorLayerFeatureIterator::rewind ( )
overridevirtual

reset the iterator to the starting position

Implements QgsAbstractFeatureIterator.

Definition at line 374 of file qgsvectorlayerfeatureiterator.cpp.

◆ rewindEditBuffer()

void QgsVectorLayerFeatureIterator::rewindEditBuffer ( )
protected
Note
not available in Python bindings

Definition at line 563 of file qgsvectorlayerfeatureiterator.cpp.

◆ setInterruptionChecker()

void QgsVectorLayerFeatureIterator::setInterruptionChecker ( QgsInterruptionChecker interruptionChecker)
overridevirtual

Attach an object that can be queried regularly by the iterator to check if it must stopped.

This is mostly useful for iterators where a single nextFeature()/fetchFeature() iteration might be very long. A typical use case is the WFS provider. When nextFeature()/fetchFeature() is reasonably fast, it is not necessary to implement this method. The default implementation does nothing.

Since
QGIS 2.16
Note
not available in Python bindings

Reimplemented from QgsAbstractFeatureIterator.

Definition at line 405 of file qgsvectorlayerfeatureiterator.cpp.

◆ updateChangedAttributes()

void QgsVectorLayerFeatureIterator::updateChangedAttributes ( QgsFeature f)
protected

Update feature with uncommitted attribute updates.

Note
not available in Python bindings

Definition at line 1041 of file qgsvectorlayerfeatureiterator.cpp.

◆ updateFeatureGeometry()

void QgsVectorLayerFeatureIterator::updateFeatureGeometry ( QgsFeature f)
protected

Update feature with uncommitted geometry updates.

Note
not available in Python bindings

Definition at line 1064 of file qgsvectorlayerfeatureiterator.cpp.

◆ useAddedFeature()

void QgsVectorLayerFeatureIterator::useAddedFeature ( const QgsFeature src,
QgsFeature f 
)
protected
Note
not available in Python bindings

Definition at line 445 of file qgsvectorlayerfeatureiterator.cpp.

◆ useChangedAttributeFeature()

void QgsVectorLayerFeatureIterator::useChangedAttributeFeature ( QgsFeatureId  fid,
const QgsGeometry geom,
QgsFeature f 
)
protected
Note
not available in Python bindings

Definition at line 525 of file qgsvectorlayerfeatureiterator.cpp.

Member Data Documentation

◆ mChangedFeaturesIterator

QgsFeatureIterator QgsVectorLayerFeatureIterator::mChangedFeaturesIterator
protected

Definition at line 222 of file qgsvectorlayerfeatureiterator.h.

◆ mChangedFeaturesRequest

QgsFeatureRequest QgsVectorLayerFeatureIterator::mChangedFeaturesRequest
protected

Definition at line 221 of file qgsvectorlayerfeatureiterator.h.

◆ mExpressionFieldInfo

QMap<int, QgsExpression *> QgsVectorLayerFeatureIterator::mExpressionFieldInfo
protected

Definition at line 239 of file qgsvectorlayerfeatureiterator.h.

◆ mFetchAddedFeaturesIt

QgsFeatureMap::ConstIterator QgsVectorLayerFeatureIterator::mFetchAddedFeaturesIt
protected

Definition at line 230 of file qgsvectorlayerfeatureiterator.h.

◆ mFetchChangedGeomIt

QgsGeometryMap::ConstIterator QgsVectorLayerFeatureIterator::mFetchChangedGeomIt
protected

Definition at line 229 of file qgsvectorlayerfeatureiterator.h.

◆ mFetchConsidered

QSet<QgsFeatureId> QgsVectorLayerFeatureIterator::mFetchConsidered
protected

Definition at line 228 of file qgsvectorlayerfeatureiterator.h.

◆ mFetchedFid

bool QgsVectorLayerFeatureIterator::mFetchedFid
protected

Definition at line 232 of file qgsvectorlayerfeatureiterator.h.

◆ mFetchJoinInfo

QMap<const QgsVectorLayerJoinInfo *, QgsVectorLayerFeatureIterator::FetchJoinInfo> QgsVectorLayerFeatureIterator::mFetchJoinInfo
protected

Information about joins used in the current select() statement.

Allows faster mapping of attribute ids compared to mVectorJoins

Definition at line 237 of file qgsvectorlayerfeatureiterator.h.

◆ mFilterRect

QgsRectangle QgsVectorLayerFeatureIterator::mFilterRect
protected

Definition at line 224 of file qgsvectorlayerfeatureiterator.h.

◆ mHasVirtualAttributes

bool QgsVectorLayerFeatureIterator::mHasVirtualAttributes
protected

Definition at line 241 of file qgsvectorlayerfeatureiterator.h.

◆ mProviderIterator

QgsFeatureIterator QgsVectorLayerFeatureIterator::mProviderIterator
protected

Definition at line 220 of file qgsvectorlayerfeatureiterator.h.

◆ mProviderRequest

QgsFeatureRequest QgsVectorLayerFeatureIterator::mProviderRequest
protected

Definition at line 219 of file qgsvectorlayerfeatureiterator.h.

◆ mTransform

QgsCoordinateTransform QgsVectorLayerFeatureIterator::mTransform
protected

Definition at line 225 of file qgsvectorlayerfeatureiterator.h.


The documentation for this class was generated from the following files: