Encapsulates a QGIS project, including sets of map layers and their styles, layouts, annotations, canvases, etc. More...

#include <qgsproject.h>

Inheritance diagram for QgsProject:

[legend]

Public Types
enum	ReadFlag { FlagDontResolveLayers = 1 << 0, FlagDontLoadLayouts = 1 << 1 }
	Flags which control project read behavior. More...

Public Slots
void	registerTranslatableContainers (QgsTranslationContext translationContext, QgsAttributeEditorContainer parent, const QString &layerId)
	Registers the containers that require translation into the translationContext. More...

void	registerTranslatableObjects (QgsTranslationContext *translationContext)
	Registers the objects that require translation into the translationContext. More...

void	setDirty (bool b=true)
	Flag the project as dirty (modified). More...

void	setPresetHomePath (const QString &path)
	Sets the project's home path. More...

void	setSnappingConfig (const QgsSnappingConfig &snappingConfig)
	The snapping configuration for this project. More...

Signals
void	avoidIntersectionsLayersChanged ()
	Emitted whenever avoidIntersectionsLayers has changed. More...

void	backgroundColorChanged ()
	Emitted whenever the project's canvas background color has been changed. More...

void	cleared ()
	Emitted when the project is cleared (and additionally when an open project is cleared just before a new project is read). More...

void	collectAttachedFiles (QgsStringMap &files)
	Emitted whenever the project is saved to a qgz file. More...

void	crsChanged ()
	Emitted when the CRS of the project has changed. More...

void	customVariablesChanged ()
	Emitted whenever the expression variables stored in the project have been changed. More...

void	ellipsoidChanged (const QString &ellipsoid)
	Emitted when the project ellipsoid is changed. More...

void	fileNameChanged ()
	Emitted when the file name of the project changes. More...

void	homePathChanged ()
	Emitted when the home path of the project changes. More...

void	isDirtyChanged (bool dirty)
	Emitted when the project dirty status changes. More...

void	labelingEngineSettingsChanged ()
	Emitted when global configuration of the labeling engine changes. More...

void	layerLoaded (int i, int n)
	Emitted when a layer from a projects was read. More...

void	layerRemoved (const QString &layerId)
	Emitted after a layer was removed from the registry. More...

void	layersAdded (const QList< QgsMapLayer *> &layers)
	Emitted when one or more layers were added to the registry. More...

void	layersRemoved (const QStringList &layerIds)
	Emitted after one or more layers were removed from the registry. More...

void	layersWillBeRemoved (const QStringList &layerIds)
	Emitted when one or more layers are about to be removed from the registry. More...

void	layersWillBeRemoved (const QList< QgsMapLayer *> &layers)
	Emitted when one or more layers are about to be removed from the registry. More...

void	layerWasAdded (QgsMapLayer *layer)
	Emitted when a layer was added to the registry. More...

void	layerWillBeRemoved (const QString &layerId)
	Emitted when a layer is about to be removed from the registry. More...

void	layerWillBeRemoved (QgsMapLayer *layer)
	Emitted when a layer is about to be removed from the registry. More...

void	legendLayersAdded (const QList< QgsMapLayer *> &layers)
	Emitted, when a layer was added to the registry and the legend. More...

void	loadingLayer (const QString &layerName)
	Emitted when a layer is loaded. More...

void	loadingLayerMessageReceived (const QString &layerName, const QList< QgsReadWriteContext::ReadWriteMessage > &messages)
	Emitted when loading layers has produced some messages. More...

void	mapScalesChanged ()
	Emitted when the list of custom project map scales changes. More...

void	mapThemeCollectionChanged ()
	Emitted when the map theme collection changes. More...

void	metadataChanged ()
	Emitted when the project's metadata is changed. More...

void	missingDatumTransforms (const QStringList &missingTransforms)
	Emitted when datum transforms stored in the project are not available locally. More...

Q_DECL_DEPRECATED void	nonIdentifiableLayersChanged (QStringList nonIdentifiableLayers)
	Emitted when the list of layer which are excluded from map identification changes. More...

void	oldProjectVersionWarning (const QString &)
	Emitted when an old project file is read. More...

void	projectColorsChanged ()
	Emitted whenever the project's color scheme has been changed. More...

void	projectSaved ()
	Emitted when the project file has been written and closed. More...

void	readMapLayer (QgsMapLayer *mapLayer, const QDomElement &layerNode)
	Emitted after the basic initialization of a layer from the project file is done. More...

void	readProject (const QDomDocument &)
	Emitted when a project is being read. More...

void	readProjectWithContext (const QDomDocument &, QgsReadWriteContext &context)
	Emitted when a project is being read. More...

void	removeAll ()
	Emitted when all layers are removed, before layersWillBeRemoved() and layerWillBeRemoved() signals are emitted. More...

void	selectionColorChanged ()
	Emitted whenever the project's selection color has been changed. More...

void	snappingConfigChanged (const QgsSnappingConfig &config)
	Emitted whenever the configuration for snapping has changed. More...

void	topologicalEditingChanged ()
	Emitted when the topological editing flag has changed. More...

void	transactionGroupsChanged ()
	Emitted whenever a new transaction group has been created or a transaction group has been removed. More...

void	transformContextChanged ()
	Emitted when the project transformContext() is changed. More...

void	writeMapLayer (QgsMapLayer *mapLayer, QDomElement &layerElem, QDomDocument &doc)
	Emitted when a layer is being saved. More...

void	writeProject (QDomDocument &)
	Emitted when the project is being written. More...

Public Member Functions
	QgsProject (QObject *parent=nullptr)
	Create a new QgsProject. More...

	~QgsProject () override

QString	absoluteFilePath () const
	Returns full absolute path to the project file if the project is stored in a file system - derived from fileName(). More...

QString	absolutePath () const
	Returns full absolute path to the project folder if the project is stored in a file system - derived from fileName(). More...

bool	accept (QgsStyleEntityVisitorInterface *visitor) const
	Accepts the specified style entity visitor, causing it to visit all style entities associated with the project. More...

QgsMapLayer *	addMapLayer (QgsMapLayer *mapLayer, bool addToLegend=true, bool takeOwnership=true)
	Add a layer to the map of loaded layers. More...

QList< QgsMapLayer * >	addMapLayers (const QList< QgsMapLayer *> &mapLayers, bool addToLegend=true, bool takeOwnership=true)
	Add a list of layers to the map of loaded layers. More...

QgsAnnotationManager *	annotationManager ()
	Returns pointer to the project's annotation manager. More...

const QgsAnnotationManager *	annotationManager () const
	Returns a const pointer to the project's annotation manager. More...

QgsUnitTypes::AreaUnit	areaUnits () const
	Convenience function to query default area measurement units for project. More...

QString	attachedFile (const QString &fileName) const
	Returns the path to an attached file known by fileName. More...

QgsStringMap	attachedFiles () const
	Returns a map of all attached files with relative paths and real paths. More...

bool	autoTransaction () const
	Transactional editing means that on supported datasources (postgres databases) the edit state of all tables that originate from the same database are synchronized and executed in a server side transaction. More...

const QgsAuxiliaryStorage *	auxiliaryStorage () const
	Returns the current const auxiliary storage. More...

QgsAuxiliaryStorage *	auxiliaryStorage ()
	Returns the current auxiliary storage. More...

QList< QgsVectorLayer * >	avoidIntersectionsLayers () const
	A list of layers with which intersections should be avoided. More...

QColor	backgroundColor () const
	Returns the default background color used by default map canvases. More...

QString	baseName () const
	Returns the base name of the project file without the path and without extension - derived from fileName(). More...

const QgsBookmarkManager *	bookmarkManager () const
	Returns the project's bookmark manager, which manages bookmarks within the project. More...

QgsBookmarkManager *	bookmarkManager ()
	Returns the project's bookmark manager, which manages bookmarks within the project. More...

void	clear ()
	Clears the project, removing all settings and resetting it back to an empty, default state. More...

int	count () const
	Returns the number of registered layers. More...

QgsLayerTreeGroup *	createEmbeddedGroup (const QString &groupName, const QString &projectFilePath, const QStringList &invisibleLayers, QgsProject::ReadFlags flags=nullptr)
	Create layer group instance defined in an arbitrary project file. More...

bool	createEmbeddedLayer (const QString &layerId, const QString &projectFilePath, QList< QDomNode > &brokenNodes, bool saveFlag=true, QgsProject::ReadFlags flags=nullptr)
	Creates a maplayer instance defined in an arbitrary project file. More...

QgsExpressionContext	createExpressionContext () const override
	This method needs to be reimplemented in all classes which implement this interface and return an expression context. More...

QgsExpressionContextScope *	createExpressionContextScope () const override
	This method needs to be reimplemented in all classes which implement this interface and return an expression context scope. More...

QgsCoordinateReferenceSystem	crs () const
	Returns the project's native coordinate reference system. More...

QVariantMap	customVariables () const
	A map of custom project variables. More...

QgsCoordinateReferenceSystem	defaultCrsForNewLayers () const
	Returns the default CRS for new layers based on the settings and the current project CRS. More...

QgsUnitTypes::DistanceUnit	distanceUnits () const
	Convenience function to query default distance measurement units for project. More...

void	dumpProperties () const
	Dump out current project properties to stderr. More...

QString	ellipsoid () const
	Returns a proj string representing the project's ellipsoid setting, e.g., "WGS84". More...

QStringList	entryList (const QString &scope, const QString &key) const
	Returns keys with values – do not return keys that contain other keys. More...

QString	error () const
	Returns error message from previous read/write. More...

bool	evaluateDefaultValues () const
	Should default values be evaluated on provider side when requested and not when committed. More...

Q_DECL_DEPRECATED QFileInfo	fileInfo () const
	Returns QFileInfo object for the project's associated file. More...

QString	fileName () const
	Returns the project's file name. More...

void	generateTsFile (const QString &locale)
	Triggers the collection strings of .qgs to be included in ts file and calls writeTsFile() More...

QString	homePath () const
	Returns the project's home path. More...

bool	isDirty () const
	Returns `true` if the project has been modified since the last write() More...

bool	isZipped () const
	Returns `true` if the project comes from a zip archive, `false` otherwise. More...

const QgsLabelingEngineSettings &	labelingEngineSettings () const
	Returns project's global labeling engine settings. More...

QDateTime	lastModified () const
	Returns last modified time of the project file as returned by the file system (or other project storage). More...

QString	layerIsEmbedded (const QString &id) const
	Returns project file path if layer is embedded from other project file. Returns empty string if layer is not embedded. More...

template<typename T >
QVector< T >	layers () const
	Returns a list of registered map layers with a specified layer type. More...

QgsMapLayerStore *	layerStore ()
	Returns a pointer to the project's internal layer store. More...

const QgsMapLayerStore *	layerStore () const
	Returns a pointer to the project's internal layer store. More...

QgsLayerTreeRegistryBridge *	layerTreeRegistryBridge () const
	Returns pointer to the helper class that synchronizes map layer registry with layer tree. More...

QgsLayerTree *	layerTreeRoot () const
	Returns pointer to the root (invisible) node of the project's layer tree. More...

const QgsLayoutManager *	layoutManager () const
	Returns the project's layout manager, which manages compositions within the project. More...

QgsLayoutManager *	layoutManager ()
	Returns the project's layout manager, which manages compositions within the project. More...

Q_INVOKABLE QgsMapLayer *	mapLayer (const QString &layerId) const
	Retrieve a pointer to a registered layer by layer ID. More...

template<class T >
T	mapLayer (const QString &layerId) const
	Retrieve a pointer to a registered layer by `layerId` converted to type T. More...

QMap< QString, QgsMapLayer * >	mapLayers (const bool validOnly=false) const
	Returns a map of all registered layers by layer ID. More...

QList< QgsMapLayer * >	mapLayersByName (const QString &layerName) const
	Retrieve a list of matching registered layers by layer name. More...

QList< QgsMapLayer * >	mapLayersByShortName (const QString &shortName) const
	Retrieves a list of matching registered layers by layer shortName. More...

template<typename T >
QVector< T >	mapLayersByShortName (const QString &shortName) const
	Retrieves a list of matching registered layers by layer shortName with a specified layer type, if layer's short name is empty a match with layer's name is attempted. More...

QVector< double >	mapScales () const
	Returns the list of custom project map scales. More...

QgsMapThemeCollection *	mapThemeCollection ()
	Returns pointer to the project's map theme collection. More...

const QgsProjectMetadata &	metadata () const
	Returns a reference to the project's metadata store. More...

Q_DECL_DEPRECATED QStringList	nonIdentifiableLayers () const
	Gets the list of layers which currently should not be taken into account on map identification. More...

QgsPathResolver	pathResolver () const
	Returns path resolver object with considering whether the project uses absolute or relative paths and using current project's path. More...

QString	presetHomePath () const
	Returns any manual project home path setting, or an empty string if not set. More...

QgsProjectStorage *	projectStorage () const
	Returns pointer to project storage implementation that handles read/write of the project file. More...

bool	read (const QString &filename, QgsProject::ReadFlags flags=nullptr)
	Reads given project file from the given file. More...

bool	read (QgsProject::ReadFlags flags=nullptr)
	Reads the project from its currently associated file (see fileName() ). More...

bool	readBoolEntry (const QString &scope, const QString &key, bool def=false, bool *ok=nullptr) const

double	readDoubleEntry (const QString &scope, const QString &key, double def=0, bool *ok=nullptr) const

QString	readEntry (const QString &scope, const QString &key, const QString &def=QString(), bool *ok=nullptr) const

bool	readLayer (const QDomNode &layerNode)
	Reads the layer described in the associated DOM node. More...

QStringList	readListEntry (const QString &scope, const QString &key, const QStringList &def=QStringList(), bool *ok=nullptr) const
	Key value accessors. More...

int	readNumEntry (const QString &scope, const QString &key, int def=0, bool *ok=nullptr) const

QString	readPath (const QString &filename) const
	Turn filename read from the project file to an absolute path. More...

QgsRelationManager *	relationManager () const

void	reloadAllLayers ()
	Reload all registered layer's provider data caches, synchronising the layer with any changes in the datasource. More...

void	removeAllMapLayers ()
	Removes all registered layers. More...

bool	removeEntry (const QString &scope, const QString &key)
	Remove the given key. More...

void	removeMapLayer (const QString &layerId)
	Remove a layer from the registry by layer ID. More...

void	removeMapLayer (QgsMapLayer *layer)
	Remove a layer from the registry. More...

void	removeMapLayers (const QStringList &layerIds)
	Remove a set of layers from the registry by layer ID. More...

void	removeMapLayers (const QList< QgsMapLayer *> &layers)
	Remove a set of layers from the registry. More...

Q_DECL_DEPRECATED QSet< QgsMapLayer * >	requiredLayers () const
	Returns a set of map layers that are required in the project and therefore they should not get removed from the project. More...

QColor	selectionColor () const
	Returns the color used to highlight selected features. More...

void	setAreaUnits (QgsUnitTypes::AreaUnit unit)
	Sets the default area measurement units for the project. More...

void	setAutoTransaction (bool autoTransaction)
	Transactional editing means that on supported datasources (postgres databases) the edit state of all tables that originate from the same database are synchronized and executed in a server side transaction. More...

void	setAvoidIntersectionsLayers (const QList< QgsVectorLayer *> &layers)
	A list of layers with which intersections should be avoided. More...

void	setBackgroundColor (const QColor &color)
	Sets the default background color used by default map canvases. More...

void	setBadLayerHandler (QgsProjectBadLayerHandler *handler)
	Change handler for missing layers. More...

void	setCrs (const QgsCoordinateReferenceSystem &crs, bool adjustEllipsoid=false)
	Sets the project's native coordinate reference system. More...

void	setCustomVariables (const QVariantMap &customVariables)
	A map of custom project variables. More...

void	setDistanceUnits (QgsUnitTypes::DistanceUnit unit)
	Sets the default distance measurement units for the project. More...

void	setEllipsoid (const QString &ellipsoid)
	Sets the project's ellipsoid from a proj string representation, e.g., "WGS84". More...

void	setEvaluateDefaultValues (bool evaluateDefaultValues)
	Defines if default values should be evaluated on provider side when requested and not when committed. More...

void	setFileName (const QString &name)
	Sets the file name associated with the project. More...

void	setLabelingEngineSettings (const QgsLabelingEngineSettings &settings)
	Sets project's global labeling engine settings. More...

void	setMapScales (const QVector< double > &scales)
	Sets the list of custom project map scales. More...

void	setMetadata (const QgsProjectMetadata &metadata)
	Sets the project's metadata store. More...

Q_DECL_DEPRECATED void	setNonIdentifiableLayers (const QList< QgsMapLayer *> &layers)
	Set a list of layers which should not be taken into account on map identification. More...

Q_DECL_DEPRECATED void	setNonIdentifiableLayers (const QStringList &layerIds)
	Set a list of layers which should not be taken into account on map identification. More...

void	setProjectColors (const QgsNamedColorList &colors)
	Sets the colors for the project's color scheme (see QgsProjectColorScheme). More...

Q_DECL_DEPRECATED void	setRequiredLayers (const QSet< QgsMapLayer *> &layers)
	Configures a set of map layers that are required in the project and therefore they should not get removed from the project. More...

void	setSelectionColor (const QColor &color)
	Sets the color used to highlight selected features. More...

void	setTitle (const QString &title)
	Sets the project's title. More...

void	setTopologicalEditing (bool enabled)
	Convenience function to set topological editing. More...

void	setTransformContext (const QgsCoordinateTransformContext &context)
	Sets the project's coordinate transform context, which stores various information regarding which datum transforms should be used when transforming points from a source to destination coordinate reference system. More...

void	setTrustLayerMetadata (bool trust)
	Sets the trust option allowing to indicate if the extent has to be read from the XML document when data source has no metadata or if the data provider has to determine it. More...

void	setUseProjectScales (bool enabled)
	Sets whether project mapScales() are enabled. More...

QgsSnappingConfig	snappingConfig () const
	The snapping configuration for this project. More...

QStringList	subkeyList (const QString &scope, const QString &key) const
	Returns keys with keys – do not return keys that contain only values. More...

QgsMapLayer *	takeMapLayer (QgsMapLayer *layer)
	Takes a layer from the registry. More...

QString	title () const
	Returns the project's title. More...

bool	topologicalEditing () const
	Convenience function to query topological editing status. More...

QgsTransactionGroup *	transactionGroup (const QString &providerKey, const QString &connString)
	Returns the matching transaction group from a provider key and connection string. More...

QMap< QPair< QString, QString >, QgsTransactionGroup * >	transactionGroups ()
	Map of transaction groups. More...

QgsCoordinateTransformContext	transformContext () const
	Returns a copy of the project's coordinate transform context, which stores various information regarding which datum transforms should be used when transforming points from a source to destination coordinate reference system. More...

QString	translate (const QString &context, const QString &sourceText, const char *disambiguation=nullptr, int n=-1) const override
	Translates the project with QTranslator and qm file. More...

bool	trustLayerMetadata () const
	Returns `true` if the trust option is activated, `false` otherwise. More...

bool	useProjectScales () const
	Returns `true` if project mapScales() are enabled. More...

int	validCount () const
	Returns the number of registered valid layers. More...

bool	write (const QString &filename)
	Writes the project to a file. More...

bool	write ()
	Writes the project to its current associated file (see fileName() ). More...

bool	writeEntry (const QString &scope, const QString &key, bool value)
	Write a boolean entry to the project file. More...

bool	writeEntry (const QString &scope, const QString &key, double value)
	Write a double entry to the project file. More...

bool	writeEntry (const QString &scope, const QString &key, int value)
	Write an integer entry to the project file. More...

bool	writeEntry (const QString &scope, const QString &key, const QString &value)
	Write a string entry to the project file. More...

bool	writeEntry (const QString &scope, const QString &key, const QStringList &value)
	Write a string list entry to the project file. More...

QString	writePath (const QString &filename) const
	Prepare a filename to save it to the project file. More...

Public Member Functions inherited from QgsExpressionContextGenerator
virtual	~QgsExpressionContextGenerator ()=default

Public Member Functions inherited from QgsExpressionContextScopeGenerator
virtual	~QgsExpressionContextScopeGenerator ()=default

Public Member Functions inherited from QgsProjectTranslator
virtual	~QgsProjectTranslator ()=default

Static Public Member Functions
static QgsProject *	instance ()
	Returns the QgsProject singleton instance. More...

Properties
QList< QgsVectorLayer * >	avoidIntersectionsLayers

QColor	backgroundColor

QgsCoordinateReferenceSystem	crs

QString	ellipsoid

QString	fileName

QString	homePath

QgsMapThemeCollection	mapThemeCollection

QgsProjectMetadata	metadata

QStringList	nonIdentifiableLayers

QgsRelationManager	relationManager

QColor	selectionColor

QgsSnappingConfig	snappingConfig

QgsCoordinateTransformContext	transformContext

Friends
class	QgsConfigCache

class	QgsProjectDirtyBlocker

class	QgsProviderRegistry

Detailed Description

Encapsulates a QGIS project, including sets of map layers and their styles, layouts, annotations, canvases, etc.

QgsProject is available both as a singleton (QgsProject::instance()) and for use as standalone objects. The QGIS project singleton always gives access to the canonical project reference open within the main QGIS application.

Note: QgsProject has two general kinds of state to make persistent. (I.e., to read and write.) First, QGIS proprietary information. Second plugin information.

Definition at line 89 of file qgsproject.h.

Member Enumeration Documentation

◆ ReadFlag

enum QgsProject::ReadFlag

Flags which control project read behavior.

Since: QGIS 3.10

Enumerator
FlagDontResolveLayers	Don't resolve layer paths (i.e. don't load any layer content). Dramatically improves project read time if the actual data from the layers is not required.
FlagDontLoadLayouts	Don't load print layouts. Improves project read time if layouts are not required, and allows projects to be safely read in background threads (since print layouts are not thread safe).

Definition at line 274 of file qgsproject.h.

Constructor & Destructor Documentation

◆ QgsProject()

QgsProject::QgsProject ( QObject * parent = nullptr )

explicit

Create a new QgsProject.

Most of the time you want to use QgsProject::instance() instead as many components of QGIS work with the singleton.

Definition at line 355 of file qgsproject.cpp.

◆ ~QgsProject()

QgsProject::~QgsProject ( )

override

Definition at line 421 of file qgsproject.cpp.

Member Function Documentation

◆ absoluteFilePath()

QString QgsProject::absoluteFilePath ( ) const

Returns full absolute path to the project file if the project is stored in a file system - derived from fileName().

Returns empty string when the project is stored in a project storage (there is no concept of paths for custom project storages).

Since: QGIS 3.2

Definition at line 630 of file qgsproject.cpp.

◆ absolutePath()

QString QgsProject::absolutePath ( ) const

Returns full absolute path to the project folder if the project is stored in a file system - derived from fileName().

Returns empty string when the project is stored in a project storage (there is no concept of paths for custom project storages).

Since: QGIS 3.2

Definition at line 619 of file qgsproject.cpp.

◆ accept()

bool QgsProject::accept ( QgsStyleEntityVisitorInterface * visitor ) const

Accepts the specified style entity visitor, causing it to visit all style entities associated with the project.

Returns true if the visitor should continue visiting other objects, or false if visiting should be canceled.

Since: QGIS 3.10

Definition at line 3332 of file qgsproject.cpp.

◆ addMapLayer()

QgsMapLayer * QgsProject::addMapLayer	(	QgsMapLayer *	mapLayer,
		bool	addToLegend = `true`,
		bool	takeOwnership = `true`
	)

Add a layer to the map of loaded layers.

The layersAdded() and layerWasAdded() signals will always be emitted. The legendLayersAdded() signal is emitted only if addToLegend is true. If you are adding multiple layers at once, you should use addMapLayers() instead.

Parameters

mapLayer	A layer to add to the registry
addToLegend	If `true` (by default), the layer will be added to the legend and to the main canvas. If you have a private layer you can set this parameter to `false` to hide it.
takeOwnership	Ownership will be transferred to the layer registry. If you specify `false` here you have take care of deleting the layer yourself. Not available in Python.

Returns: nullptr if unable to add layer, otherwise pointer to newly added layer

See also: addMapLayers

Note: As a side-effect QgsProject is made dirty.; Use addMapLayers if adding more than one layer at a time; takeOwnership is not available in the Python bindings - the registry will always take ownership

See also: addMapLayers()

Definition at line 3019 of file qgsproject.cpp.

◆ addMapLayers()

QList< QgsMapLayer * > QgsProject::addMapLayers	(	const QList< QgsMapLayer *> &	mapLayers,
		bool	addToLegend = `true`,
		bool	takeOwnership = `true`
	)

Add a list of layers to the map of loaded layers.

The layersAdded() and layerWasAdded() signals will always be emitted. The legendLayersAdded() signal is emitted only if addToLegend is true.

Parameters

mapLayers	A list of layer which should be added to the registry
addToLegend	If `true` (by default), the layers will be added to the legend and to the main canvas. If you have a private layer you can set this parameter to `false` to hide it.
takeOwnership	Ownership will be transferred to the layer registry. If you specify `false` here you have take care of deleting the layers yourself. Not available in Python.

Returns: a list of the map layers that were added successfully. If a layer or already exists in the registry, it will not be part of the returned QList.

Note: As a side-effect QgsProject is made dirty.; takeOwnership is not available in the Python bindings - the registry will always take ownership

See also: addMapLayer()

Since: QGIS 1.8

Definition at line 2981 of file qgsproject.cpp.

◆ annotationManager() [1/2]

QgsAnnotationManager * QgsProject::annotationManager ( )

Returns pointer to the project's annotation manager.

Since: QGIS 3.0

Definition at line 2755 of file qgsproject.cpp.

◆ annotationManager() [2/2]

const QgsAnnotationManager * QgsProject::annotationManager ( ) const

Returns a const pointer to the project's annotation manager.

Since: QGIS 3.0

Definition at line 2760 of file qgsproject.cpp.

◆ areaUnits()

QgsUnitTypes::AreaUnit QgsProject::areaUnits ( ) const

Convenience function to query default area measurement units for project.

See also: distanceUnits()

Since: QGIS 2.14

Definition at line 2663 of file qgsproject.cpp.

◆ attachedFile()

QString QgsProject::attachedFile ( const QString & fileName ) const

Returns the path to an attached file known by fileName.

Note: Not available in Python bindings; Attached files are only supported by QGZ file based projects

See also: collectAttachedFiles()

Since: QGIS 3.8

◆ attachedFiles()

QgsStringMap QgsProject::attachedFiles ( ) const

Returns a map of all attached files with relative paths and real paths.

Note: Not available in Python bindings; Attached files are only supported by QGZ file based projects

See also: collectAttachedFiles(); attachedFile()

Since: QGIS 3.8

◆ autoTransaction()

bool QgsProject::autoTransaction ( ) const

Transactional editing means that on supported datasources (postgres databases) the edit state of all tables that originate from the same database are synchronized and executed in a server side transaction.

Since: QGIS 2.16

Definition at line 2814 of file qgsproject.cpp.

◆ auxiliaryStorage() [1/2]

const QgsAuxiliaryStorage * QgsProject::auxiliaryStorage ( ) const

Returns the current const auxiliary storage.

Since: QGIS 3.0

Definition at line 3147 of file qgsproject.cpp.

◆ auxiliaryStorage() [2/2]

QgsAuxiliaryStorage * QgsProject::auxiliaryStorage ( )

Returns the current auxiliary storage.

Since: QGIS 3.0

Definition at line 3152 of file qgsproject.cpp.

◆ avoidIntersectionsLayers()

QList<QgsVectorLayer *> QgsProject::avoidIntersectionsLayers ( ) const

A list of layers with which intersections should be avoided.

Since: QGIS 3.0

◆ avoidIntersectionsLayersChanged

void QgsProject::avoidIntersectionsLayersChanged ( )

signal

Emitted whenever avoidIntersectionsLayers has changed.

Since: QGIS 3.0

◆ backgroundColor()

QColor QgsProject::backgroundColor ( ) const

Returns the default background color used by default map canvases.

See also: setBackgroundColor()

Since: QGIS 3.10

◆ backgroundColorChanged

void QgsProject::backgroundColorChanged ( )

signal

Emitted whenever the project's canvas background color has been changed.

See also: setBackgroundColor()

Since: QGIS 3.10

◆ baseName()

QString QgsProject::baseName ( ) const

Returns the base name of the project file without the path and without extension - derived from fileName().

Since: QGIS 3.2

Definition at line 641 of file qgsproject.cpp.

◆ bookmarkManager() [1/2]

const QgsBookmarkManager * QgsProject::bookmarkManager ( ) const

Returns the project's bookmark manager, which manages bookmarks within the project.

Note: not available in Python bindings

Since: QGIS 3.10

Definition at line 2735 of file qgsproject.cpp.

◆ bookmarkManager() [2/2]

QgsBookmarkManager * QgsProject::bookmarkManager ( )

Returns the project's bookmark manager, which manages bookmarks within the project.

Since: QGIS 3.10

Definition at line 2740 of file qgsproject.cpp.

◆ clear()

void QgsProject::clear ( )

Clears the project, removing all settings and resetting it back to an empty, default state.

See also: cleared()

Since: QGIS 2.4

Definition at line 713 of file qgsproject.cpp.

◆ cleared

void QgsProject::cleared ( )

signal

Emitted when the project is cleared (and additionally when an open project is cleared just before a new project is read).

See also: clear()

Since: QGIS 3.2

◆ collectAttachedFiles

void QgsProject::collectAttachedFiles ( QgsStringMap & files )

signal

Emitted whenever the project is saved to a qgz file.

This can be used to package additional files into the qgz file by modifying the files map.

Map keys represent relative paths inside the qgz file, map values represent the path to the source file.

Note: Not available in Python bindings; Only will be emitted with QGZ project files

See also: attachedFiles(); attachedFile()

Since: QGIS 3.8

◆ count()

int QgsProject::count ( ) const

Returns the number of registered layers.

Definition at line 2843 of file qgsproject.cpp.

◆ createEmbeddedGroup()

QgsLayerTreeGroup * QgsProject::createEmbeddedGroup	(	const QString &	groupName,
		const QString &	projectFilePath,
		const QStringList &	invisibleLayers,
		QgsProject::ReadFlags	flags = `nullptr`
	)

Create layer group instance defined in an arbitrary project file.

The optional flags argument can be used to control layer reading behavior.

Since: QGIS 2.4

Definition at line 2521 of file qgsproject.cpp.

◆ createEmbeddedLayer()

bool QgsProject::createEmbeddedLayer	(	const QString &	layerId,
		const QString &	projectFilePath,
		QList< QDomNode > &	brokenNodes,
		bool	saveFlag = `true`,
		QgsProject::ReadFlags	flags = `nullptr`
	)

Creates a maplayer instance defined in an arbitrary project file.

Caller takes ownership.

The optional flags argument can be used to specify flags which control layer reading.

Returns: the layer or 0 in case of error

Note: not available in Python bindings

Definition at line 2434 of file qgsproject.cpp.

◆ createExpressionContext()

QgsExpressionContext QgsProject::createExpressionContext ( ) const

overridevirtual

This method needs to be reimplemented in all classes which implement this interface and return an expression context.

Since: QGIS 3.0

Implements QgsExpressionContextGenerator.

Definition at line 1625 of file qgsproject.cpp.

◆ createExpressionContextScope()

QgsExpressionContextScope * QgsProject::createExpressionContextScope ( ) const

overridevirtual

This method needs to be reimplemented in all classes which implement this interface and return an expression context scope.

Since: QGIS 3.0

Implements QgsExpressionContextScopeGenerator.

Definition at line 1635 of file qgsproject.cpp.

◆ crs()

QgsCoordinateReferenceSystem QgsProject::crs ( ) const

Returns the project's native coordinate reference system.

See also: setCrs(); ellipsoid()

Since: QGIS 3.0

◆ crsChanged

void QgsProject::crsChanged ( )

signal

Emitted when the CRS of the project has changed.

Since: QGIS 3.0

◆ customVariables()

QVariantMap QgsProject::customVariables ( ) const

A map of custom project variables.

To get all available variables including generated ones use QgsExpressionContextUtils::projectScope() instead.

Definition at line 1551 of file qgsproject.cpp.

◆ customVariablesChanged

void QgsProject::customVariablesChanged ( )

signal

Emitted whenever the expression variables stored in the project have been changed.

Since: QGIS 3.0

◆ defaultCrsForNewLayers()

QgsCoordinateReferenceSystem QgsProject::defaultCrsForNewLayers ( ) const

Returns the default CRS for new layers based on the settings and the current project CRS.

Definition at line 3078 of file qgsproject.cpp.

◆ distanceUnits()

QgsUnitTypes::DistanceUnit QgsProject::distanceUnits ( ) const

Convenience function to query default distance measurement units for project.

See also: setDistanceUnits(); areaUnits()

Since: QGIS 2.14

Definition at line 2645 of file qgsproject.cpp.

◆ dumpProperties()

void QgsProject::dumpProperties ( ) const

Dump out current project properties to stderr.

Definition at line 2367 of file qgsproject.cpp.

◆ ellipsoid()

QString QgsProject::ellipsoid ( ) const

Returns a proj string representing the project's ellipsoid setting, e.g., "WGS84".

See also: setEllipsoid(); crs()

Since: QGIS 3.0

◆ ellipsoidChanged

void QgsProject::ellipsoidChanged ( const QString & ellipsoid )

signal

Emitted when the project ellipsoid is changed.

See also: setEllipsoid(); ellipsoid()

Since: QGIS 3.0

◆ entryList()

QStringList QgsProject::entryList	(	const QString &	scope,
		const QString &	key
	)		const

Returns keys with values – do not return keys that contain other keys.

Note: equivalent to QgsSettings entryList()

Definition at line 2333 of file qgsproject.cpp.

◆ error()

QString QgsProject::error ( ) const

Returns error message from previous read/write.

Definition at line 2408 of file qgsproject.cpp.

◆ evaluateDefaultValues()

bool QgsProject::evaluateDefaultValues ( ) const

Should default values be evaluated on provider side when requested and not when committed.

Since: QGIS 2.16

Definition at line 2610 of file qgsproject.cpp.

◆ fileInfo()

QFileInfo QgsProject::fileInfo ( ) const

Returns QFileInfo object for the project's associated file.

Note: The use of this method is discouraged since QGIS 3.2 as it only works with project files stored in the file system. It is recommended to use absoluteFilePath(), baseName(), lastModifiedTime() as replacements that are aware of the fact that projects may be saved in other project storages.

See also: fileName()

Deprecated:: since QGIS 3.2 use absoluteFilePath(), baseName() or lastModifiedTime() instead

Definition at line 595 of file qgsproject.cpp.

◆ fileName()

QString QgsProject::fileName ( ) const

Returns the project's file name.

This is the file or the storage URI which contains the project's XML representation.

See also: setFileName(); fileInfo()

◆ fileNameChanged

void QgsProject::fileNameChanged ( )

signal

Emitted when the file name of the project changes.

◆ generateTsFile()

void QgsProject::generateTsFile ( const QString & locale )

Triggers the collection strings of .qgs to be included in ts file and calls writeTsFile()

Since: QGIS 3.4

Definition at line 3305 of file qgsproject.cpp.

◆ homePath()

QString QgsProject::homePath ( ) const

Returns the project's home path.

This will either be a manually set home path (see presetHomePath()) or the path containing the project file itself.

This method always returns the absolute path to the project's home. See presetHomePath() to retrieve any manual project home path override (e.g. relative home paths).

See also: setPresetHomePath(); presetHomePath(); homePathChanged()

◆ homePathChanged

void QgsProject::homePathChanged ( )

signal

Emitted when the home path of the project changes.

See also: setPresetHomePath(); homePath(); presetHomePath()

◆ instance()

QgsProject * QgsProject::instance ( )

static

Returns the QgsProject singleton instance.

Definition at line 442 of file qgsproject.cpp.

◆ isDirty()

bool QgsProject::isDirty ( ) const

Returns true if the project has been modified since the last write()

Definition at line 468 of file qgsproject.cpp.

◆ isDirtyChanged

void QgsProject::isDirtyChanged ( bool dirty )

signal

Emitted when the project dirty status changes.

Parameters

dirty true if the project is in a dirty state and has pending unsaved changes.

Since: QGIS 3.2

◆ isZipped()

bool QgsProject::isZipped ( ) const

Returns true if the project comes from a zip archive, false otherwise.

Definition at line 2976 of file qgsproject.cpp.

◆ labelingEngineSettings()

const QgsLabelingEngineSettings & QgsProject::labelingEngineSettings ( ) const

Returns project's global labeling engine settings.

Since: QGIS 3.0

Definition at line 1587 of file qgsproject.cpp.

◆ labelingEngineSettingsChanged

void QgsProject::labelingEngineSettingsChanged ( )

signal

Emitted when global configuration of the labeling engine changes.

Since: QGIS 3.0

◆ lastModified()

QDateTime QgsProject::lastModified ( ) const

Returns last modified time of the project file as returned by the file system (or other project storage).

Since: QGIS 3.2

Definition at line 605 of file qgsproject.cpp.

◆ layerIsEmbedded()

QString QgsProject::layerIsEmbedded ( const QString & id ) const

Returns project file path if layer is embedded from other project file. Returns empty string if layer is not embedded.

Definition at line 2424 of file qgsproject.cpp.

◆ layerLoaded

void QgsProject::layerLoaded	(	int	i,
		int	n
	)

signal

Emitted when a layer from a projects was read.

Parameters

i	current layer
n	number of layers

◆ layerRemoved

void QgsProject::layerRemoved ( const QString & layerId )

signal

Emitted after a layer was removed from the registry.

Parameters

layerId The ID of the layer removed.

Note: Consider using layersRemoved() instead

See also: layerWillBeRemoved()

◆ layers()

template<typename T >

QVector<T> QgsProject::layers ( ) const

inline

Returns a list of registered map layers with a specified layer type.

Example:

QVector<QgsVectorLayer*> vectorLayers = QgsProject::instance()->layers<QgsVectorLayer*>();

Note: not available in Python bindings

See also: mapLayers()

Since: QGIS 2.16

Definition at line 821 of file qgsproject.h.

◆ layersAdded

void QgsProject::layersAdded ( const QList< QgsMapLayer *> & layers )

signal

Emitted when one or more layers were added to the registry.

This signal is also emitted for layers added to the registry, but not to the legend.

Parameters

layers List of layers which have been added.

See also: legendLayersAdded(); layerWasAdded()

◆ layersRemoved

void QgsProject::layersRemoved ( const QStringList & layerIds )

signal

Emitted after one or more layers were removed from the registry.

Parameters

layerIds A list of IDs of the layers which were removed.

See also: layersWillBeRemoved()

◆ layerStore() [1/2]

QgsMapLayerStore * QgsProject::layerStore ( )

Returns a pointer to the project's internal layer store.

/since QGIS 3.0

Definition at line 1592 of file qgsproject.cpp.

◆ layerStore() [2/2]

const QgsMapLayerStore * QgsProject::layerStore ( ) const

Returns a pointer to the project's internal layer store.

/since QGIS 3.0

Definition at line 1597 of file qgsproject.cpp.

◆ layersWillBeRemoved [1/2]

void QgsProject::layersWillBeRemoved ( const QStringList & layerIds )

signal

Emitted when one or more layers are about to be removed from the registry.

Parameters

layerIds A list of IDs for the layers which are to be removed.

See also: layerWillBeRemoved(); layersRemoved()

◆ layersWillBeRemoved [2/2]

void QgsProject::layersWillBeRemoved ( const QList< QgsMapLayer *> & layers )

signal

Emitted when one or more layers are about to be removed from the registry.

Parameters

layers A list of layers which are to be removed.

See also: layerWillBeRemoved(); layersRemoved()

◆ layerTreeRegistryBridge()

QgsLayerTreeRegistryBridge* QgsProject::layerTreeRegistryBridge ( ) const

inline

Returns pointer to the helper class that synchronizes map layer registry with layer tree.

Since: QGIS 2.4

Definition at line 575 of file qgsproject.h.

◆ layerTreeRoot()

QgsLayerTree * QgsProject::layerTreeRoot ( ) const

Returns pointer to the root (invisible) node of the project's layer tree.

Since: QGIS 2.4

Definition at line 2745 of file qgsproject.cpp.

◆ layerWasAdded

void QgsProject::layerWasAdded ( QgsMapLayer * layer )

signal

Emitted when a layer was added to the registry.

Note: Consider using layersAdded() instead

See also: layersAdded()

◆ layerWillBeRemoved [1/2]

void QgsProject::layerWillBeRemoved ( const QString & layerId )

signal

Emitted when a layer is about to be removed from the registry.

Parameters

layerId The ID of the layer to be removed.

Note: Consider using layersWillBeRemoved() instead

See also: layersWillBeRemoved(); layerRemoved()

◆ layerWillBeRemoved [2/2]

void QgsProject::layerWillBeRemoved ( QgsMapLayer * layer )

signal

Emitted when a layer is about to be removed from the registry.

Parameters

layer The layer to be removed.

Note: Consider using layersWillBeRemoved() instead

See also: layersWillBeRemoved(); layerRemoved()

◆ layoutManager() [1/2]

const QgsLayoutManager * QgsProject::layoutManager ( ) const

Returns the project's layout manager, which manages compositions within the project.

Note: not available in Python bindings

Since: QGIS 3.0

Definition at line 2725 of file qgsproject.cpp.

◆ layoutManager() [2/2]

QgsLayoutManager * QgsProject::layoutManager ( )

Returns the project's layout manager, which manages compositions within the project.

Since: QGIS 3.0

Definition at line 2730 of file qgsproject.cpp.

◆ legendLayersAdded

void QgsProject::legendLayersAdded ( const QList< QgsMapLayer *> & layers )

signal

Emitted, when a layer was added to the registry and the legend.

Layers can also be private layers, which are signalled by layersAdded() and layerWasAdded() but will not be advertised by this signal.

Parameters

layers List of QgsMapLayer which were added to the legend.

◆ loadingLayer

void QgsProject::loadingLayer ( const QString & layerName )

signal

Emitted when a layer is loaded.

◆ loadingLayerMessageReceived

void QgsProject::loadingLayerMessageReceived	(	const QString &	layerName,
		const QList< QgsReadWriteContext::ReadWriteMessage > &	messages
	)

signal

Emitted when loading layers has produced some messages.

Parameters

layerName	the layer name
messages	a list of pairs of Qgis::MessageLevel and messages

Since: 3.2

◆ mapLayer() [1/2]

QgsMapLayer * QgsProject::mapLayer ( const QString & layerId ) const

Retrieve a pointer to a registered layer by layer ID.

Parameters

layerId ID of layer to retrieve

Returns: matching layer, or nullptr if no matching layer found

See also: mapLayersByName(); mapLayers()

Definition at line 2853 of file qgsproject.cpp.

◆ mapLayer() [2/2]

template<class T >

T QgsProject::mapLayer ( const QString & layerId ) const

inline

Retrieve a pointer to a registered layer by layerId converted to type T.

This is a convenience template. A nullptr will be returned if the layer is not found or if it cannot be cast to type T.

QgsVectorLayer *layer = project->mapLayer<QgsVectorLayer*>( layerId );

See also: mapLayer(); mapLayers()

Since: QGIS 3.6

Definition at line 765 of file qgsproject.h.

◆ mapLayers()

QMap< QString, QgsMapLayer * > QgsProject::mapLayers ( const bool validOnly = false ) const

Returns a map of all registered layers by layer ID.

Parameters

validOnly if set only valid layers will be returned

See also: mapLayer(); mapLayersByName(); layers()

Definition at line 3068 of file qgsproject.cpp.

◆ mapLayersByName()

QList< QgsMapLayer * > QgsProject::mapLayersByName ( const QString & layerName ) const

Retrieve a list of matching registered layers by layer name.

Parameters

layerName name of layers to match

Returns: list of matching layers

See also: mapLayer(); mapLayers()

Definition at line 2858 of file qgsproject.cpp.

◆ mapLayersByShortName() [1/2]

QList< QgsMapLayer * > QgsProject::mapLayersByShortName ( const QString & shortName ) const

Retrieves a list of matching registered layers by layer shortName.

If layer's short name is empty a match with layer's name is attempted.

Returns: list of matching layers

See also: mapLayer(); mapLayers()

Since: QGIS 3.10

Definition at line 2863 of file qgsproject.cpp.

◆ mapLayersByShortName() [2/2]

template<typename T >

QVector<T> QgsProject::mapLayersByShortName ( const QString & shortName ) const

inline

Retrieves a list of matching registered layers by layer shortName with a specified layer type, if layer's short name is empty a match with layer's name is attempted.

Parameters

shortName short name of layers to match

Returns: list of matching layers

See also: mapLayer(); mapLayers()

Note: not available in Python bindings

Since: QGIS 3.10

Definition at line 838 of file qgsproject.h.

◆ mapScales()

QVector< double > QgsProject::mapScales ( ) const

Returns the list of custom project map scales.

The scales list consists of a list of scale denominator values, e.g. 1000 for a 1:1000 scale.

See also: setMapScales(); mapScalesChanged()

Since: QGIS 3.10

Definition at line 3271 of file qgsproject.cpp.

◆ mapScalesChanged

void QgsProject::mapScalesChanged ( )

signal

Emitted when the list of custom project map scales changes.

See also: mapScales(); setMapScales()

Since: QGIS 3.10

◆ mapThemeCollection()

QgsMapThemeCollection* QgsProject::mapThemeCollection ( )

Returns pointer to the project's map theme collection.

Note: renamed in QGIS 3.0, formerly QgsVisibilityPresetCollection

Since: QGIS 2.12

◆ mapThemeCollectionChanged

void QgsProject::mapThemeCollectionChanged ( )

signal

Emitted when the map theme collection changes.

This only happens when the map theme collection is reset. Any pointer previously received from mapThemeCollection() must no longer be used after this signal is emitted. You must still connect to signals from the map theme collection if you want to be notified about new map themes being added and map themes being removed.

Since: QGIS 3.0

◆ metadata()

const QgsProjectMetadata& QgsProject::metadata ( ) const

Returns a reference to the project's metadata store.

See also: setMetadata(); metadataChanged()

Since: QGIS 3.2

◆ metadataChanged

void QgsProject::metadataChanged ( )

signal

Emitted when the project's metadata is changed.

See also: setMetadata(); metadata()

Since: QGIS 3.2

◆ missingDatumTransforms

void QgsProject::missingDatumTransforms ( const QStringList & missingTransforms )

signal

Emitted when datum transforms stored in the project are not available locally.

Since: QGIS 3.0

◆ nonIdentifiableLayers()

Q_DECL_DEPRECATED QStringList QgsProject::nonIdentifiableLayers ( ) const

Gets the list of layers which currently should not be taken into account on map identification.

Deprecated:: since QGIS 3.4 use QgsMapLayer::setFlags() instead

◆ nonIdentifiableLayersChanged

Q_DECL_DEPRECATED void QgsProject::nonIdentifiableLayersChanged ( QStringList nonIdentifiableLayers )

signal

Emitted when the list of layer which are excluded from map identification changes.

Deprecated:: since QGIS 3.4

◆ oldProjectVersionWarning

void QgsProject::oldProjectVersionWarning ( const QString & )

signal

Emitted when an old project file is read.

◆ pathResolver()

QgsPathResolver QgsProject::pathResolver ( ) const

Returns path resolver object with considering whether the project uses absolute or relative paths and using current project's path.

Since: QGIS 3.0

Definition at line 2372 of file qgsproject.cpp.

◆ presetHomePath()

QString QgsProject::presetHomePath ( ) const

Returns any manual project home path setting, or an empty string if not set.

This path may be a relative path. See homePath() to retrieve a path which is always an absolute path.

See also: homePath(); setPresetHomePath(); homePathChanged()

Since: QGIS 3.2

Definition at line 2715 of file qgsproject.cpp.

◆ projectColorsChanged

void QgsProject::projectColorsChanged ( )

signal

Emitted whenever the project's color scheme has been changed.

See also: setProjectColors()

Since: QGIS 3.6

◆ projectSaved

void QgsProject::projectSaved ( )

signal

Emitted when the project file has been written and closed.

◆ projectStorage()

QgsProjectStorage * QgsProject::projectStorage ( ) const

Returns pointer to project storage implementation that handles read/write of the project file.

If the project file is stored in the local file system, returns nullptr. The project storage object is inferred from fileName() of the project.

Since: QGIS 3.2

Definition at line 600 of file qgsproject.cpp.

◆ read() [1/2]

bool QgsProject::read	(	const QString &	filename,
		QgsProject::ReadFlags	flags = `nullptr`
	)

Reads given project file from the given file.

Parameters

filename	name of project file to read
flags	optional flags which control the read behavior of projects

Returns: true if project file has been read successfully

Definition at line 1068 of file qgsproject.cpp.

◆ read() [2/2]

bool QgsProject::read ( QgsProject::ReadFlags flags = nullptr )

Reads the project from its currently associated file (see fileName() ).

The flags argument can be used to specify optional flags which control the read behavior of projects.

Returns: true if project file has been read successfully

Definition at line 1077 of file qgsproject.cpp.

◆ readBoolEntry()

bool QgsProject::readBoolEntry	(	const QString &	scope,
		const QString &	key,
		bool	def = `false`,
		bool *	ok = `nullptr`
	)		const

Definition at line 2300 of file qgsproject.cpp.

◆ readDoubleEntry()

double QgsProject::readDoubleEntry	(	const QString &	scope,
		const QString &	key,
		double	def = `0`,
		bool *	ok = `nullptr`
	)		const

Definition at line 2280 of file qgsproject.cpp.

◆ readEntry()

QString QgsProject::readEntry	(	const QString &	scope,
		const QString &	key,
		const QString &	def = `QString()`,
		bool *	ok = `nullptr`
	)		const

Definition at line 2229 of file qgsproject.cpp.

◆ readLayer()

bool QgsProject::readLayer ( const QDomNode & layerNode )

Reads the layer described in the associated DOM node.

Note: This method is mainly for use by QgsProjectBadLayerHandler subclasses that may fix definition of bad layers with the user's help in GUI. Calling this method with corrected DOM node adds the layer back to the project.

Parameters

layerNode represents a QgsProject DOM node that encodes a specific layer.

Definition at line 1779 of file qgsproject.cpp.

◆ readListEntry()

QStringList QgsProject::readListEntry	(	const QString &	scope,
		const QString &	key,
		const QStringList &	def = `QStringList()`,
		bool *	ok = `nullptr`
	)		const

Key value accessors.

keys would be the familiar QgsSettings-like '/' delimited entries, implying a hierarchy of keys and corresponding values

Definition at line 2202 of file qgsproject.cpp.

◆ readMapLayer

void QgsProject::readMapLayer	(	QgsMapLayer *	mapLayer,
		const QDomElement &	layerNode
	)

signal

Emitted after the basic initialization of a layer from the project file is done.

You can use this signal to read additional information from the project file.

Parameters

mapLayer	The map layer which is being initialized
layerNode	The layer node from the project file

◆ readNumEntry()

int QgsProject::readNumEntry	(	const QString &	scope,
		const QString &	key,
		int	def = `0`,
		bool *	ok = `nullptr`
	)		const

Definition at line 2253 of file qgsproject.cpp.

◆ readPath()

QString QgsProject::readPath ( const QString & filename ) const

Turn filename read from the project file to an absolute path.

Definition at line 2393 of file qgsproject.cpp.

◆ readProject

void QgsProject::readProject ( const QDomDocument & )

signal

Emitted when a project is being read.

◆ readProjectWithContext

void QgsProject::readProjectWithContext	(	const QDomDocument &	,
		QgsReadWriteContext &	context
	)

signal

Emitted when a project is being read.

And passing the /a context

◆ registerTranslatableContainers

void QgsProject::registerTranslatableContainers	(	QgsTranslationContext *	translationContext,
		QgsAttributeEditorContainer *	parent,
		const QString &	layerId
	)

slot

Registers the containers that require translation into the translationContext.

This is a recursive function to get all the child containers.

Parameters

translationContext	where the objects will be registered
parent	parent-container containing list of children
layerId	to store under the correct context

Since: QGIS 3.4

Definition at line 499 of file qgsproject.cpp.

◆ registerTranslatableObjects

void QgsProject::registerTranslatableObjects ( QgsTranslationContext * translationContext )

slot

Registers the objects that require translation into the translationContext.

So there can be created a ts file with these values.

Since: QGIS 3.4

Definition at line 517 of file qgsproject.cpp.

◆ relationManager()

QgsRelationManager* QgsProject::relationManager ( ) const

◆ reloadAllLayers()

void QgsProject::reloadAllLayers ( )

Reload all registered layer's provider data caches, synchronising the layer with any changes in the datasource.

See also: QgsMapLayer::reload()

Definition at line 3058 of file qgsproject.cpp.

◆ removeAll

void QgsProject::removeAll ( )

signal

Emitted when all layers are removed, before layersWillBeRemoved() and layerWillBeRemoved() signals are emitted.

The layersWillBeRemoved() and layerWillBeRemoved() signals will still be emitted following this signal. You can use this signal to do easy (and fast) cleanup.

◆ removeAllMapLayers()

void QgsProject::removeAllMapLayers ( )

Removes all registered layers.

If the registry has ownership of any layers these layers will also be deleted.

Note: As a side-effect the QgsProject instance is marked dirty.; Calling this method will cause the removeAll() signal to be emitted.

See also: removeMapLayer(); removeMapLayers()

Definition at line 3053 of file qgsproject.cpp.

◆ removeEntry()

bool QgsProject::removeEntry	(	const QString &	scope,
		const QString &	key
	)

Remove the given key.

Definition at line 2321 of file qgsproject.cpp.

◆ removeMapLayer() [1/2]

void QgsProject::removeMapLayer ( const QString & layerId )

Remove a layer from the registry by layer ID.

The specified layer will be removed from the registry. If the registry has ownership of the layer then it will also be deleted.

Parameters

layerId ID of the layer to remove

Note: As a side-effect the QgsProject instance is marked dirty.

See also: removeMapLayers(); removeAllMapLayers()

Definition at line 3038 of file qgsproject.cpp.

◆ removeMapLayer() [2/2]

void QgsProject::removeMapLayer ( QgsMapLayer * layer )

Remove a layer from the registry.

The specified layer will be removed from the registry. If the registry has ownership of the layer then it will also be deleted.

Parameters

layer The layer to remove. nullptr values are ignored.

Note: As a side-effect the QgsProject instance is marked dirty.

See also: removeMapLayers(); removeAllMapLayers()

Definition at line 3043 of file qgsproject.cpp.

◆ removeMapLayers() [1/2]

void QgsProject::removeMapLayers ( const QStringList & layerIds )

Remove a set of layers from the registry by layer ID.

The specified layers will be removed from the registry. If the registry has ownership of any layers these layers will also be deleted.

Parameters

layerIds list of IDs of the layers to remove

Note: As a side-effect the QgsProject instance is marked dirty.

See also: removeMapLayer(); removeAllMapLayers()

Since: QGIS 1.8

Definition at line 3028 of file qgsproject.cpp.

◆ removeMapLayers() [2/2]

void QgsProject::removeMapLayers ( const QList< QgsMapLayer *> & layers )

Remove a set of layers from the registry.

The specified layers will be removed from the registry. If the registry has ownership of any layers these layers will also be deleted.

Parameters

layers A list of layers to remove. nullptr values are ignored.

Note: As a side-effect the QgsProject instance is marked dirty.

See also: removeMapLayer(); removeAllMapLayers()

Definition at line 3033 of file qgsproject.cpp.

◆ requiredLayers()

QSet< QgsMapLayer * > QgsProject::requiredLayers ( ) const

Returns a set of map layers that are required in the project and therefore they should not get removed from the project.

The set of layers may be configured by users in project properties. and it is mainly a hint for the user interface to protect users from removing layers that important in the project. The removeMapLayer(), removeMapLayers() calls do not block removal of layers listed here.

Deprecated:: since QGIS 3.4 use QgsMapLayer::flags() instead

Since: QGIS 3.2

Definition at line 3175 of file qgsproject.cpp.

◆ selectionColor()

QColor QgsProject::selectionColor ( ) const

Returns the color used to highlight selected features.

See also: setSelectionColor()

Since: QGIS 3.10

◆ selectionColorChanged

void QgsProject::selectionColorChanged ( )

signal

Emitted whenever the project's selection color has been changed.

See also: setSelectionColor()

Since: QGIS 3.10

◆ setAreaUnits()

void QgsProject::setAreaUnits ( QgsUnitTypes::AreaUnit unit )

Sets the default area measurement units for the project.

See also: areaUnits(); setDistanceUnits()

Since: QGIS 3.0

Definition at line 2676 of file qgsproject.cpp.

◆ setAutoTransaction()

void QgsProject::setAutoTransaction ( bool autoTransaction )

Transactional editing means that on supported datasources (postgres databases) the edit state of all tables that originate from the same database are synchronized and executed in a server side transaction.

Make sure that this is only called when all layers are not in edit mode.

Since: QGIS 2.16

Definition at line 2819 of file qgsproject.cpp.

◆ setAvoidIntersectionsLayers()

void QgsProject::setAvoidIntersectionsLayers ( const QList< QgsVectorLayer *> & layers )

A list of layers with which intersections should be avoided.

Since: QGIS 3.0

Definition at line 1615 of file qgsproject.cpp.

◆ setBackgroundColor()

void QgsProject::setBackgroundColor ( const QColor & color )

Sets the default background color used by default map canvases.

See also: backgroundColor()

Since: QGIS 3.10

Definition at line 3225 of file qgsproject.cpp.

◆ setBadLayerHandler()

void QgsProject::setBadLayerHandler ( QgsProjectBadLayerHandler * handler )

Change handler for missing layers.

Deletes old handler and takes ownership of the new one.

Definition at line 2418 of file qgsproject.cpp.

◆ setCrs()

void QgsProject::setCrs	(	const QgsCoordinateReferenceSystem &	crs,
		bool	adjustEllipsoid = `false`
	)

Sets the project's native coordinate reference system.

If adjustEllipsoid is set to true, the ellpsoid of this project will be set to the ellipsoid imposed by the CRS.

See also: crs(); setEllipsoid()

Since: QGIS 3.0

Definition at line 660 of file qgsproject.cpp.

◆ setCustomVariables()

void QgsProject::setCustomVariables ( const QVariantMap & customVariables )

A map of custom project variables.

Be careful not to set generated variables.

Definition at line 1556 of file qgsproject.cpp.

◆ setDirty

void QgsProject::setDirty ( bool b = true )

slot

Flag the project as dirty (modified).

If this flag is set, the user will be asked to save changes to the project before closing the current project.

Note: promoted to public slot in 2.16

Since: QGIS 2.4

Definition at line 473 of file qgsproject.cpp.

◆ setDistanceUnits()

void QgsProject::setDistanceUnits ( QgsUnitTypes::DistanceUnit unit )

Sets the default distance measurement units for the project.

See also: distanceUnits(); setAreaUnits()

Since: QGIS 3.0

Definition at line 2658 of file qgsproject.cpp.

◆ setEllipsoid()

void QgsProject::setEllipsoid ( const QString & ellipsoid )

Sets the project's ellipsoid from a proj string representation, e.g., "WGS84".

See also: ellipsoid(); setCrs()

Since: QGIS 3.0

Definition at line 683 of file qgsproject.cpp.

◆ setEvaluateDefaultValues()

void QgsProject::setEvaluateDefaultValues ( bool evaluateDefaultValues )

Defines if default values should be evaluated on provider side when requested and not when committed.

Since: QGIS 2.16

Definition at line 2615 of file qgsproject.cpp.

◆ setFileName()

void QgsProject::setFileName ( const QString & name )

Sets the file name associated with the project.

This is the file or the storage URI which contains the project's XML representation.

Parameters

name	project file name

See also: fileName()

Definition at line 570 of file qgsproject.cpp.

◆ setLabelingEngineSettings()

void QgsProject::setLabelingEngineSettings ( const QgsLabelingEngineSettings & settings )

Sets project's global labeling engine settings.

Since: QGIS 3.0

Definition at line 1581 of file qgsproject.cpp.

◆ setMapScales()

void QgsProject::setMapScales ( const QVector< double > & scales )

Sets the list of custom project map scales.

The scales list consists of a list of scale denominator values, e.g. 1000 for a 1:1000 scale.

See also: mapScales(); mapScalesChanged()

Since: QGIS 3.10

Definition at line 3253 of file qgsproject.cpp.

◆ setMetadata()

void QgsProject::setMetadata ( const QgsProjectMetadata & metadata )

Sets the project's metadata store.

See also: metadata(); metadataChanged()

Since: QGIS 3.2

Definition at line 3162 of file qgsproject.cpp.

◆ setNonIdentifiableLayers() [1/2]

void QgsProject::setNonIdentifiableLayers ( const QList< QgsMapLayer *> & layers )

Set a list of layers which should not be taken into account on map identification.

Deprecated:: since QGIS 3.4 use QgsMapLayer::setFlags() instead

Definition at line 2765 of file qgsproject.cpp.

◆ setNonIdentifiableLayers() [2/2]

void QgsProject::setNonIdentifiableLayers ( const QStringList & layerIds )

Set a list of layers which should not be taken into account on map identification.

Deprecated:: since QGIS 3.4 use QgsMapLayer::setFlags() instead

Definition at line 2784 of file qgsproject.cpp.

◆ setPresetHomePath

void QgsProject::setPresetHomePath ( const QString & path )

slot

Sets the project's home path.

If an empty path is specified than the home path will be automatically determined from the project's file path.

See also: presetHomePath(); homePath(); homePathChanged()

Since: QGIS 3.2

Definition at line 485 of file qgsproject.cpp.

◆ setProjectColors()

void QgsProject::setProjectColors ( const QgsNamedColorList & colors )

Sets the colors for the project's color scheme (see QgsProjectColorScheme).

See also: projectColorsChanged()

Since: QGIS 3.6

Definition at line 3205 of file qgsproject.cpp.

◆ setRequiredLayers()

void QgsProject::setRequiredLayers ( const QSet< QgsMapLayer *> & layers )

Configures a set of map layers that are required in the project and therefore they should not get removed from the project.

The set of layers may be configured by users in project properties. and it is mainly a hint for the user interface to protect users from removing layers that important in the project. The removeMapLayer(), removeMapLayers() calls do not block removal of layers listed here.

Deprecated:: since QGIS 3.4 use QgsMapLayer::setFlags() instead

Since: QGIS 3.2

Definition at line 3190 of file qgsproject.cpp.

◆ setSelectionColor()

void QgsProject::setSelectionColor ( const QColor & color )

Sets the color used to highlight selected features.

See also: selectionColor()

Since: QGIS 3.10

Definition at line 3239 of file qgsproject.cpp.

◆ setSnappingConfig

void QgsProject::setSnappingConfig ( const QgsSnappingConfig & snappingConfig )

slot

The snapping configuration for this project.

Since: QGIS 3.0

Definition at line 916 of file qgsproject.cpp.

◆ setTitle()

void QgsProject::setTitle ( const QString & title )

Sets the project's title.

Parameters

title new title

Note: Since QGIS 3.2 this is just a shortcut to setting the title in the project's metadata().

See also: title()

Since: QGIS 2.4

Definition at line 451 of file qgsproject.cpp.

◆ setTopologicalEditing()

void QgsProject::setTopologicalEditing ( bool enabled )

Convenience function to set topological editing.

Definition at line 2634 of file qgsproject.cpp.

◆ setTransformContext()

void QgsProject::setTransformContext ( const QgsCoordinateTransformContext & context )

Sets the project's coordinate transform context, which stores various information regarding which datum transforms should be used when transforming points from a source to destination coordinate reference system.

See also: transformContext(); transformContextChanged()

Since: QGIS 3.0

Definition at line 698 of file qgsproject.cpp.

◆ setTrustLayerMetadata()

void QgsProject::setTrustLayerMetadata ( bool trust )

Sets the trust option allowing to indicate if the extent has to be read from the XML document when data source has no metadata or if the data provider has to determine it.

Moreover, when this option is activated, primary key unicity is not checked for views and materialized views with Postgres provider.

Parameters

trust true to trust the project, false otherwise

Since: QGIS 3.0

Definition at line 3101 of file qgsproject.cpp.

◆ setUseProjectScales()

void QgsProject::setUseProjectScales ( bool enabled )

Sets whether project mapScales() are enabled.

See also: useProjectScales(); setMapScales()

Since: QGIS 3.10

Definition at line 3291 of file qgsproject.cpp.

◆ snappingConfig()

QgsSnappingConfig QgsProject::snappingConfig ( ) const

The snapping configuration for this project.

Since: QGIS 3.0

◆ snappingConfigChanged

void QgsProject::snappingConfigChanged ( const QgsSnappingConfig & config )

signal

Emitted whenever the configuration for snapping has changed.

◆ subkeyList()

QStringList QgsProject::subkeyList	(	const QString &	scope,
		const QString &	key
	)		const

Returns keys with keys – do not return keys that contain only values.

Note: equivalent to QgsSettings subkeyList()

Definition at line 2350 of file qgsproject.cpp.

◆ takeMapLayer()

QgsMapLayer * QgsProject::takeMapLayer ( QgsMapLayer * layer )

Takes a layer from the registry.

If the layer was owned by the project, the layer will be returned without deleting it. The caller takes ownership of the layer and is responsible for deleting it.

See also: removeMapLayer()

Since: QGIS 3.0

Definition at line 3048 of file qgsproject.cpp.

◆ title()

QString QgsProject::title ( ) const

Returns the project's title.

See also: setTitle()

Note: Since QGIS 3.2 this is just a shortcut to retrieving the title from the project's metadata().

Definition at line 463 of file qgsproject.cpp.

◆ topologicalEditing()

bool QgsProject::topologicalEditing ( ) const

Convenience function to query topological editing status.

Definition at line 2640 of file qgsproject.cpp.

◆ topologicalEditingChanged

void QgsProject::topologicalEditingChanged ( )

signal

Emitted when the topological editing flag has changed.

Since: QGIS 3.0

◆ transactionGroup()

QgsTransactionGroup * QgsProject::transactionGroup	(	const QString &	providerKey,
		const QString &	connString
	)

Returns the matching transaction group from a provider key and connection string.

Returns nullptr if a matching transaction group is not available.

Since: QGIS 3.2

Definition at line 3073 of file qgsproject.cpp.

◆ transactionGroups()

QMap< QPair< QString, QString >, QgsTransactionGroup * > QgsProject::transactionGroups ( )

Map of transaction groups.

QPair( providerKey, connString ) -> transactionGroup

Note: Not available in Python bindings

Since: QGIS 2.16

Definition at line 2832 of file qgsproject.cpp.

◆ transactionGroupsChanged

void QgsProject::transactionGroupsChanged ( )

signal

Emitted whenever a new transaction group has been created or a transaction group has been removed.

Since: QGIS 3.0

◆ transformContext()

QgsCoordinateTransformContext QgsProject::transformContext ( ) const

Returns a copy of the project's coordinate transform context, which stores various information regarding which datum transforms should be used when transforming points from a source to destination coordinate reference system.

See also: setTransformContext(); transformContextChanged()

Since: QGIS 3.0

◆ transformContextChanged

void QgsProject::transformContextChanged ( )

signal

Emitted when the project transformContext() is changed.

See also: transformContext()

Since: QGIS 3.0

◆ translate()

QString QgsProject::translate	(	const QString &	context,
		const QString &	sourceText,
		const char *	disambiguation = `nullptr`,
		int	n = `-1`
	)		const

overridevirtual

Translates the project with QTranslator and qm file.

Returns: the result string (in case there is no QTranslator loaded the sourceText)

Parameters

context	describing layer etc.
sourceText	is the identifier of this text
disambiguation	it's the disambiguation
n	if -1 uses the appropriate form

Since: QGIS 3.4

Implements QgsProjectTranslator.

Definition at line 3316 of file qgsproject.cpp.

◆ trustLayerMetadata()

bool QgsProject::trustLayerMetadata ( ) const

inline

Returns true if the trust option is activated, false otherwise.

This option allows indicateing if the extent has to be read from the XML document when data source has no metadata or if the data provider has to determine it. Moreover, when this option is activated, primary key unicity is not checked for views and materialized views with Postgres provider.

Since: QGIS 3.0

Definition at line 1039 of file qgsproject.h.

◆ useProjectScales()

bool QgsProject::useProjectScales ( ) const

Returns true if project mapScales() are enabled.

See also: setUseProjectScales(); mapScales()

Since: QGIS 3.10

Definition at line 3300 of file qgsproject.cpp.

◆ validCount()

int QgsProject::validCount ( ) const

Returns the number of registered valid layers.

Definition at line 2848 of file qgsproject.cpp.

◆ write() [1/2]

bool QgsProject::write ( const QString & filename )

Writes the project to a file.

Parameters

filename destination file

Returns: true if project was written successfully

Note: calling this implicitly sets the project's filename (see setFileName() ); isDirty() will be set to false if project is successfully written

Since: QGIS 3.0

Definition at line 1803 of file qgsproject.cpp.

◆ write() [2/2]

bool QgsProject::write ( )

Writes the project to its current associated file (see fileName() ).

Returns: true if project was written successfully

Note: isDirty() will be set to false if project is successfully written

Definition at line 1812 of file qgsproject.cpp.