Class: QgsProject

class qgis.core.QgsProject

Bases: PyQt5.QtCore.QObject, QgsExpressionContextGenerator, QgsExpressionContextScopeGenerator, QgsProjectTranslator

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.

QgsProject(parent: QObject = None) Create a new QgsProject.

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

Enums

AvoidIntersectionsMode

Bases: enum.IntEnum

FileFormat

Bases: enum.IntEnum

ReadFlag

Bases: enum.IntEnum

Methods

absoluteFilePath

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

absolutePath

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

accept

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

addMapLayer

Add a layer to the map of loaded layers.

addMapLayers

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

annotationManager

Returns pointer to the project's annotation manager.

areaUnits

Convenience function to query default area measurement units for project.

attachedFiles

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

attachmentIdentifier

Returns an identifier for an attachment file path An attachment identifier is a string which does not depend on the project archive storage location.

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.

auxiliaryStorage

Returns the current auxiliary storage.

avoidIntersectionsLayers

A list of layers with which intersections should be avoided.

avoidIntersectionsMode

Returns the current avoid intersections mode.

backgroundColor

Returns the default background color used by default map canvases.

baseName

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

bookmarkManager

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

childEvent

clear

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

connectNotify

count

Returns the number of registered layers.

createAttachedFile

Attaches a file to the project

createEmbeddedGroup

Create layer group instance defined in an arbitrary project file.

createExpressionContext

rtype

QgsExpressionContext

createExpressionContextScope

rtype

QgsExpressionContextScope

crs

Returns the project's native coordinate reference system.

customEvent

customVariables

A map of custom project variables.

dataDefinedServerProperties

Returns the data defined properties used for overrides in user defined server parameters

defaultCrsForNewLayers

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

disconnectNotify

displaySettings

Returns the project's display settings, which settings and properties relating to how a QgsProject should display values such as map coordinates and bearings.

distanceUnits

Convenience function to query default distance measurement units for project.

dumpProperties

Dump out current project properties to stderr

ellipsoid

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

entryList

Returns a list of child keys with values which exist within the the specified scope and key.

error

Returns error message from previous read/write

evaluateDefaultValues

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

fileInfo

Returns QFileInfo object for the project's associated file.

fileName

Returns the project's file name.

filePathStorage

Returns the type of paths used when storing file paths in a QGS/QGZ project file.

generateTsFile

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

homePath

Returns the project's home path.

instance

Returns the QgsProject singleton instance

isDirty

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

isSignalConnected

isZipped

Returns True if the project comes from a zip archive, False otherwise.

labelingEngineSettings

Returns project's global labeling engine settings

lastModified

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

lastSaveDateTime

Returns the date and time when the project was last saved.

lastSaveVersion

Returns the QGIS version which the project was last saved using.

layerIsEmbedded

Returns the source project file path if the layer with matching id is embedded from other project file.

layerStore

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

layerTreeRegistryBridge

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

layerTreeRoot

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

layoutManager

Returns the project's layout manager, which manages print layouts, atlases and reports within the project.

mainAnnotationLayer

Returns the main annotation layer associated with the project.

mapLayer

Retrieve a pointer to a registered layer by layer ID.

mapLayers

Returns a map of all registered layers by layer ID.

mapLayersByName

Retrieve a list of matching registered layers by layer name.

mapLayersByShortName

Retrieves a list of matching registered layers by layer shortName.

mapScales

Returns the list of custom project map scales.

mapThemeCollection

Returns pointer to the project's map theme collection.

metadata

Returns a reference to the project's metadata store.

nonIdentifiableLayers

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

originalPath

Returns the original path associated with the project.

pathResolver

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

presetHomePath

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

projectStorage

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

read

Reads given project file from the given file.

readBoolEntry

Reads a boolean from the specified scope and key.

readDoubleEntry

Reads a double from the specified scope and key.

readEntry

Reads a string from the specified scope and key.

readLayer

Reads the layer described in the associated DOM node.

readListEntry

Reads a string list from the specified scope and key.

readNumEntry

Reads an integer from the specified scope and key.

readPath

Transforms a filename read from the project file to an absolute path.

receivers

registerTranslatableContainers

Registers the containers that require translation into the translationContext.

registerTranslatableObjects

Registers the objects that require translation into the translationContext.

relationManager

rtype

QgsRelationManager

reloadAllLayers

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

removeAllMapLayers

Removes all registered layers.

removeAttachedFile

Removes the attached file

removeEntry

Remove the given key from the specified scope.

removeMapLayer

Remove a layer from the registry by layer ID.

removeMapLayers

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

requiredLayers

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

resolveAttachmentIdentifier

Resolves an attachment identifier to a attachment file path

saveUser

Returns the user name that did the last save.

saveUserFullName

Returns the full user name that did the last save.

selectionColor

Returns the color used to highlight selected features

sender

senderSignalIndex

setAreaUnits

Sets the default area measurement units for the project.

setAutoTransaction

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.

setAvoidIntersectionsLayers

Sets the list of layers with which intersections should be avoided.

setAvoidIntersectionsMode

Sets the avoid intersections mode.

setBackgroundColor

Sets the default background color used by default map canvases.

setBadLayerHandler

Change handler for missing layers.

setCrs

Sets the project's native coordinate reference system.

setCustomVariables

A map of custom project variables.

setDataDefinedServerProperties

Sets the data defined properties used for overrides in user defined server parameters to properties

setDirty

Flag the project as dirty (modified).

setDistanceUnits

Sets the default distance measurement units for the project.

setEllipsoid

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

setEvaluateDefaultValues

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

setFileName

Sets the file name associated with the project.

setFilePathStorage

Sets the type of paths used when storing file paths in a QGS/QGZ project file.

setInstance

Set the current project singleton instance to project

setLabelingEngineSettings

Sets project's global labeling engine settings

setMapScales

Sets the list of custom project map scales.

setMetadata

Sets the project's metadata store.

setNonIdentifiableLayers

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

setOriginalPath

Sets the original path associated with the project.

setPresetHomePath

Sets the project's home path.

setProjectColors

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

setRequiredLayers

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

setSelectionColor

Sets the color used to highlight selected features.

setSnappingConfig

The snapping configuration for this project.

setTitle

Sets the project's title.

setTopologicalEditing

Convenience function to set topological editing

setTransformContext

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.

setTrustLayerMetadata

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.

setUseProjectScales

Sets whether project mapScales() are enabled.

snappingConfig

The snapping configuration for this project.

subkeyList

Returns a list of child keys which contain other keys that exist within the the specified scope and key.

takeMapLayer

Takes a layer from the registry.

timeSettings

Returns the project's time settings, which contains the project's temporal range and other time based settings.

timerEvent

title

Returns the project's title.

topologicalEditing

Convenience function to query topological editing status

transactionGroup

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

transformContext

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.

translate

Translates the project with QTranslator and qm file

trustLayerMetadata

Returns True if the trust option is activated, False otherwise.

useProjectScales

Returns True if project mapScales() are enabled.

validCount

Returns the number of registered valid layers.

viewSettings

Returns the project's view settings, which contains settings and properties relating to how a QgsProject should be viewed and behave inside a map canvas (e.g.

viewsManager

Returns the project's views manager, which manages map views (including 3d maps) in the project.

write

Writes the project to a file.

writeEntry

Write an integer value to the project file.

writeEntryBool

Write a boolean value to the project file.

writeEntryDouble

Write a double value to the project file.

writePath

Prepare a filename to save it to the project file.

Signals

avoidIntersectionsLayersChanged

Emitted whenever avoidIntersectionsLayers has changed.

avoidIntersectionsModeChanged

Emitted whenever the avoid intersections mode has changed.

backgroundColorChanged

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

cleared

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

crsChanged

Emitted when the CRS of the project has changed.

customVariablesChanged

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

dirtySet

Emitted when setDirty(true) is called.

ellipsoidChanged

Emitted when the project ellipsoid is changed.

fileNameChanged

Emitted when the file name of the project changes [signal]

homePathChanged

Emitted when the home path of the project changes.

isDirtyChanged

Emitted when the project dirty status changes.

labelingEngineSettingsChanged

Emitted when global configuration of the labeling engine changes.

layerLoaded

Emitted when a layer from a projects was read.

layerRemoved

Emitted after a layer was removed from the registry.

layerWasAdded

Emitted when a layer was added to the registry.

layerWillBeRemoved

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

layersAdded

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

layersRemoved

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

layersWillBeRemoved

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

legendLayersAdded

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

loadingLayer

Emitted when a layer is loaded [signal]

loadingLayerMessageReceived

Emitted when loading layers has produced some messages

mapScalesChanged

Emitted when the list of custom project map scales changes.

mapThemeCollectionChanged

Emitted when the map theme collection changes.

metadataChanged

Emitted when the project's metadata is changed.

missingDatumTransforms

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

nonIdentifiableLayersChanged

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

oldProjectVersionWarning

Emitted when an old project file is read.

projectColorsChanged

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

projectSaved

Emitted when the project file has been written and closed.

readMapLayer

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

readProject

Emitted when a project is being read.

readProjectWithContext

Emitted when a project is being read.

readVersionMismatchOccurred

Emitted when a project is read and the version of QGIS used to save the project differs from the current QGIS version.

removeAll

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

selectionColorChanged

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

snappingConfigChanged

Emitted whenever the configuration for snapping has changed.

topologicalEditingChanged

Emitted when the topological editing flag has changed.

transactionGroupsChanged

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

transformContextChanged

Emitted when the project transformContext() is changed.

writeMapLayer

Emitted when a layer is being saved.

writeProject

Emitted when the project is being written.

Attributes

AllProperties

NoProperty

WMSOnlineResource

AllProperties = 1
class AvoidIntersectionsMode(value)

Bases: enum.IntEnum

Flags which control how intersections of pre-existing feature are handled when digitizing new features.

New in version 3.14.

  • AllowIntersections: Overlap with any feature allowed when digitizing new features

  • AvoidIntersectionsCurrentLayer: Overlap with features from the active layer when digitizing new features not allowed

  • AvoidIntersectionsLayers: Overlap with features from a specified list of layers when digitizing new features not allowed

AllowIntersections = 0
AvoidIntersectionsCurrentLayer = 1
AvoidIntersectionsLayers = 2
baseClass

alias of QgsProject

class DataDefinedServerProperty

Bases: int

class FileFormat(value)

Bases: enum.IntEnum

Flags which control project read behavior.

New in version 3.12.

  • Qgz: Archive file format, supports auxiliary data

  • Qgs: Project saved in a clear text, does not support auxiliary data

Qgs = 1
Qgz = 0
baseClass

alias of QgsProject

NoProperty = 0
class ReadFlag(value)

Bases: enum.IntEnum

Flags which control project read behavior.

New in version 3.10.

  • 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).

  • FlagTrustLayerMetadata: Trust layer metadata. Improves project read time. Do not use it if layers’ extent is not fixed during the project’s use by QGIS and QGIS Server.

  • FlagDontStoreOriginalStyles: Skip the initial XML style storage for layers. Useful for minimising project load times in non-interactive contexts.

  • FlagDontLoad3DViews:

class ReadFlags
class ReadFlags(Union[QgsProject.ReadFlags, QgsProject.ReadFlag])
class ReadFlags(QgsProject.ReadFlags)

Bases: sip.wrapper

WMSOnlineResource = 2
absoluteFilePath(self) str

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).

New in version 3.2.

Return type

str

absolutePath(self) str

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).

New in version 3.2.

Return type

str

accept(self, visitor: QgsStyleEntityVisitorInterface) bool

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.

New in version 3.10.

Parameters

visitor (QgsStyleEntityVisitorInterface) –

Return type

bool

addMapLayer(self, mapLayer: QgsMapLayer, addToLegend: bool = True) QgsMapLayer

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 (QgsMapLayer) – A layer to add to the registry

  • addToLegend (bool = True) – 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.

Return type

QgsMapLayer

Returns

None if unable to add layer, otherwise pointer to newly added layer

See also

addMapLayers()

Note

As a side-effect QgsProject is made dirty.

Note

Use addMapLayers if adding more than one layer at a time

Note

takeOwnership is not available in the Python bindings - the registry will always take ownership

See also

addMapLayers()

addMapLayers(self, mapLayers: Iterable[QgsMapLayer], addToLegend: bool = True) List[QgsMapLayer]

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 (Iterable[QgsMapLayer]) – A list of layer which should be added to the registry

  • addToLegend (bool = True) – 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.

Return type

List[QgsMapLayer]

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.

Note

takeOwnership is not available in the Python bindings - the registry will always take ownership

See also

addMapLayer()

New in version 1.8.

annotationManager(self) QgsAnnotationManager

Returns pointer to the project’s annotation manager.

New in version 3.0.

Return type

QgsAnnotationManager

areaUnits(self) QgsUnitTypes.AreaUnit

Convenience function to query default area measurement units for project.

See also

distanceUnits()

New in version 2.14.

Return type

QgsUnitTypes.AreaUnit

attachedFiles(self) List[str]

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

New in version 3.22.

Return type

List[str]

attachmentIdentifier(self, attachedFile: str) str

Returns an identifier for an attachment file path An attachment identifier is a string which does not depend on the project archive storage location.

Parameters

attachedFile (str) – An attachment file path

Return type

str

Returns

An identifier for the attached file

New in version 3.22.

autoTransaction(self) bool

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.

New in version 2.16.

Return type

bool

auxiliaryStorage(self) QgsAuxiliaryStorage

Returns the current auxiliary storage.

New in version 3.0.

Return type

QgsAuxiliaryStorage

avoidIntersectionsLayers(self) List[QgsVectorLayer]

A list of layers with which intersections should be avoided.

New in version 3.0.

Return type

List[QgsVectorLayer]

avoidIntersectionsLayersChanged

Emitted whenever avoidIntersectionsLayers has changed.

New in version 3.0: [signal]

avoidIntersectionsMode(self) QgsProject.AvoidIntersectionsMode

Returns the current avoid intersections mode.

New in version 3.14.

Return type

QgsProject.AvoidIntersectionsMode

avoidIntersectionsModeChanged

Emitted whenever the avoid intersections mode has changed.

New in version 3.14: [signal]

backgroundColor(self) QColor

Returns the default background color used by default map canvases.

New in version 3.10.

Return type

QColor

backgroundColorChanged

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

New in version 3.10: [signal]

baseName(self) str

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

New in version 3.2.

Return type

str

blockDirtying

alias of ProjectDirtyBlocker

bookmarkManager(self) QgsBookmarkManager

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

New in version 3.10.

Return type

QgsBookmarkManager

childEvent(self, QChildEvent)
clear(self)

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

See also

cleared()

New in version 2.4.

cleared

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

See also

clear()

New in version 3.2: [signal]

connectNotify(self, QMetaMethod)
count(self) int

Returns the number of registered layers.

Return type

int

createAttachedFile(self, nameTemplate: str) str

Attaches a file to the project

Parameters

nameTemplate (str) – Any filename template, used as a basename for attachment file, i.e. “myfile.ext”

Return type

str

Returns

The path to the file where the contents can be written to.

Note

If the attachment file is used as a source for a project layer, the attachment will be removed automatically when the layer is deleted.

New in version 3.22.

createEmbeddedGroup(self, groupName: str, projectFilePath: str, invisibleLayers: Iterable[str], flags: Union[QgsProject.ReadFlags, QgsProject.ReadFlag] = QgsProject.ReadFlags()) QgsLayerTreeGroup

Create layer group instance defined in an arbitrary project file.

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

New in version 2.4.

Parameters
  • groupName (str) –

  • projectFilePath (str) –

  • invisibleLayers (Iterable[str]) –

  • flags (Union[QgsProject.ReadFlags) –

Return type

QgsLayerTreeGroup

createExpressionContext(self) QgsExpressionContext
Return type

QgsExpressionContext

createExpressionContextScope(self) QgsExpressionContextScope
Return type

QgsExpressionContextScope

crs(self) QgsCoordinateReferenceSystem

Returns the project’s native coordinate reference system.

See also

setCrs()

See also

ellipsoid()

New in version 3.0.

Return type

QgsCoordinateReferenceSystem

crsChanged

Emitted when the CRS of the project has changed.

New in version 3.0: [signal]

customEvent(self, QEvent)
customVariables(self) Dict[str, Any]

A map of custom project variables. To get all available variables including generated ones use QgsExpressionContextUtils.projectScope() instead.

Return type

Dict[str, Any]

customVariablesChanged

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

New in version 3.0: [signal]

dataDefinedServerProperties(self) QgsPropertyCollection

Returns the data defined properties used for overrides in user defined server parameters

New in version 3.14.

Return type

QgsPropertyCollection

defaultCrsForNewLayers(self) QgsCoordinateReferenceSystem

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

Return type

QgsCoordinateReferenceSystem

dirtySet

Emitted when setDirty(true) is called.

Note

As opposed to isDirtyChanged(), this signal is invoked every time setDirty(true) is called, regardless of whether the project was already dirty.

New in version 3.20: [signal]

disconnectNotify(self, QMetaMethod)
displaySettings(self) QgsProjectDisplaySettings

Returns the project’s display settings, which settings and properties relating to how a QgsProject should display values such as map coordinates and bearings.

New in version 3.12.

Return type

QgsProjectDisplaySettings

distanceUnits(self) QgsUnitTypes.DistanceUnit

Convenience function to query default distance measurement units for project.

See also

areaUnits()

New in version 2.14.

Return type

QgsUnitTypes.DistanceUnit

dumpProperties(self)

Dump out current project properties to stderr

ellipsoid(self) str

Returns a proj string representing the project’s ellipsoid setting, e.g., “WGS84”.

See also

setEllipsoid()

See also

crs()

New in version 3.0.

Return type

str

ellipsoidChanged

Emitted when the project ellipsoid is changed.

See also

setEllipsoid()

See also

ellipsoid()

New in version 3.0: [signal]

Parameters

ellipsoid (str) –

entryList(self, scope: str, key: str) List[str]

Returns a list of child keys with values which exist within the the specified scope and key.

This method does not return keys that contain other keys. See subkeyList() to retrieve keys which contain other keys.

Note

equivalent to QgsSettings entryList()

Parameters
  • scope (str) –

  • key (str) –

Return type

List[str]

error(self) str

Returns error message from previous read/write

Return type

str

evaluateDefaultValues(self) bool

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

New in version 2.16.

Return type

bool

fileInfo(self) QFileInfo

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

Return type

QFileInfo

fileName(self) str

Returns the project’s file name. This is the file or the storage URI which contains the project’s XML representation.

See also

setFileName()

See also

fileInfo()

Return type

str

fileNameChanged

Emitted when the file name of the project changes [signal]

filePathStorage(self) Qgis.FilePathType

Returns the type of paths used when storing file paths in a QGS/QGZ project file.

New in version 3.22.

Return type

Qgis.FilePathType

generateTsFile(self, locale: str)

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

New in version 3.4.

Parameters

locale (str) –

homePath(self) str

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

presetHomePath()

Return type

str

homePathChanged

Emitted when the home path of the project changes.

See also

homePath()

See also

presetHomePath() [signal]

instance() QgsProject

Returns the QgsProject singleton instance

Return type

QgsProject

isDirty(self) bool

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

Return type

bool

isDirtyChanged

Emitted when the project dirty status changes.

Parameters

dirty (bool) – True if the project is in a dirty state and has pending unsaved changes.

New in version 3.2: [signal]

isSignalConnected(self, QMetaMethod) bool
isZipped(self) bool

Returns True if the project comes from a zip archive, False otherwise.

Return type

bool

labelingEngineSettings(self) QgsLabelingEngineSettings

Returns project’s global labeling engine settings

New in version 3.0.

Return type

QgsLabelingEngineSettings

labelingEngineSettingsChanged

Emitted when global configuration of the labeling engine changes.

New in version 3.0: [signal]

lastModified(self) QDateTime

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

New in version 3.2.

Return type

QDateTime

lastSaveDateTime(self) QDateTime

Returns the date and time when the project was last saved.

New in version 3.14.

Return type

QDateTime

lastSaveVersion(self) QgsProjectVersion

Returns the QGIS version which the project was last saved using.

New in version 3.14.

Return type

QgsProjectVersion

layerIsEmbedded(self, id: str) str

Returns the source project file path if the layer with matching id is embedded from other project file.

Returns an empty string if the matching layer is not embedded.

Parameters

id (str) –

Return type

str

layerLoaded

Emitted when a layer from a projects was read.

Parameters
  • i (int) – current layer

  • n (int) – number of layers [signal]

layerRemoved

Emitted after a layer was removed from the registry.

Parameters

layerId (str) – The ID of the layer removed.

Note

Consider using layersRemoved() instead

See also

layerWillBeRemoved() [signal]

layerStore(self) QgsMapLayerStore

Returns a pointer to the project’s internal layer store. /since QGIS 3.0

Return type

QgsMapLayerStore

layerTreeRegistryBridge(self) QgsLayerTreeRegistryBridge

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

New in version 2.4.

Return type

QgsLayerTreeRegistryBridge

layerTreeRoot(self) QgsLayerTree

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

New in version 2.4.

Return type

QgsLayerTree

layerWasAdded

Emitted when a layer was added to the registry.

Note

Consider using layersAdded() instead

See also

layersAdded() [signal]

Parameters

layer (QgsMapLayer) –

layerWillBeRemoved

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

Parameters

layerId (str) – The ID of the layer to be removed.

Note

Consider using layersWillBeRemoved() instead

See also

layerRemoved() [signal]

layerWillBeRemoved(self, layer: QgsMapLayer) 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

layerRemoved() [signal]

layersAdded

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 (Iterable[QgsMapLayer]) – List of layers which have been added.

See also

layerWasAdded() [signal]

layersRemoved

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

Parameters

layerIds (Iterable[str]) – A list of IDs of the layers which were removed.

See also

layersWillBeRemoved() [signal]

layersWillBeRemoved

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

Parameters

layerIds (Iterable[str]) – A list of IDs for the layers which are to be removed.

See also

layersRemoved() [signal]

layersWillBeRemoved(self, layers: Iterable[QgsMapLayer]) 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

layersRemoved() [signal]

layoutManager(self) QgsLayoutManager

Returns the project’s layout manager, which manages print layouts, atlases and reports within the project.

New in version 3.0.

Return type

QgsLayoutManager

legendLayersAdded

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 (Iterable[QgsMapLayer]) – List of QgsMapLayer which were added to the legend. [signal]

loadingLayer

Emitted when a layer is loaded [signal]

Parameters

layerName (str) –

loadingLayerMessageReceived

Emitted when loading layers has produced some messages

Parameters

New in version 3.2: [signal]

mainAnnotationLayer(self) QgsAnnotationLayer

Returns the main annotation layer associated with the project.

This layer is always present in projects, and will always be rendered above any other map layers during map render jobs.

It forms the default location to place new annotation items which should appear above all map layers.

New in version 3.16.

Return type

QgsAnnotationLayer

mapLayer(self, layerId: str) QgsMapLayer

Retrieve a pointer to a registered layer by layer ID.

Parameters

layerId (str) – ID of layer to retrieve

Return type

QgsMapLayer

Returns

matching layer, or None if no matching layer found

See also

mapLayers()

mapLayers(self, validOnly: bool = False) object

Returns a map of all registered layers by layer ID.

Parameters

validOnly (bool = False) – if set only valid layers will be returned

See also

mapLayer()

See also

layers()

Return type

object

mapLayersByName(self, layerName: str) List[QgsMapLayer]

Retrieve a list of matching registered layers by layer name.

Parameters

layerName (str) – name of layers to match

Return type

List[QgsMapLayer]

Returns

list of matching layers

See also

mapLayer()

See also

mapLayers()

mapLayersByShortName(self, shortName: str) List[QgsMapLayer]

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.

Return type

List[QgsMapLayer]

Returns

list of matching layers

See also

mapLayer()

See also

mapLayers()

New in version 3.10.

Parameters

shortName (str) –

mapScales(self) List[float]

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()

Deprecated since version Use: viewSettings() instead

Return type

List[float]

mapScalesChanged

Emitted when the list of custom project map scales changes.

See also

mapScales()

See also

setMapScales()

Deprecated since version Use: viewSettings() instead [signal]

mapThemeCollection(self) QgsMapThemeCollection

Returns pointer to the project’s map theme collection.

Note

renamed in QGIS 3.0, formerly QgsVisibilityPresetCollection

New in version 2.12.

Return type

QgsMapThemeCollection

mapThemeCollectionChanged

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.

New in version 3.0: [signal]

metadata(self) QgsProjectMetadata

Returns a reference to the project’s metadata store.

See also

setMetadata()

New in version 3.2.

Return type

QgsProjectMetadata

metadataChanged

Emitted when the project’s metadata is changed.

See also

setMetadata()

See also

metadata()

New in version 3.2: [signal]

missingDatumTransforms

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

New in version 3.0: [signal]

Parameters

missingTransforms (Iterable[str]) –

nonIdentifiableLayers(self) List[str]

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

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

Return type

List[str]

nonIdentifiableLayersChanged

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

Deprecated since version QGIS: 3.4 [signal]

Parameters

nonIdentifiableLayers (Iterable[str]) –

oldProjectVersionWarning

Emitted when an old project file is read.

Deprecated since version use: readVersionMismatchOccurred() instead. [signal]

originalPath(self) str

Returns the original path associated with the project.

This is intended for use with non-qgs/qgz project files (see QgsCustomProjectOpenHandler) in order to allow custom project open handlers to specify the original file name of the project. For custom project formats, it is NOT appropriate to call setFileName() with the original project path, as this causes the original (non QGIS) project file to be overwritten when the project is next saved.

New in version 3.14.

Return type

str

pathResolver(self) QgsPathResolver

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

New in version 3.0.

Return type

QgsPathResolver

presetHomePath(self) str

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()

New in version 3.2.

Return type

str

projectColorsChanged

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

New in version 3.6: [signal]

projectSaved

Emitted when the project file has been written and closed. [signal]

projectStorage(self) QgsProjectStorage

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 None. The project storage object is inferred from fileName() of the project.

New in version 3.2.

Return type

QgsProjectStorage

read(self, filename: str, flags: Union[QgsProject.ReadFlags, QgsProject.ReadFlag] = QgsProject.ReadFlags()) bool

Reads given project file from the given file.

Parameters
  • filename (str) – name of project file to read

  • flags (Union[QgsProject.ReadFlags) – optional flags which control the read behavior of projects

Returns

True if project file has been read successfully

read(self, flags: Union[QgsProject.ReadFlags, QgsProject.ReadFlag] = QgsProject.ReadFlags()) -> bool 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.

Return type

bool

Returns

True if project file has been read successfully

readBoolEntry(self, scope: str, key: str, def_: bool = False) Tuple[bool, bool]

Reads a boolean from the specified scope and key.

Parameters
  • scope (str) – entry scope (group) name

  • key (str) – entry key name. Keys are ‘/’-delimited entries, implying a hierarchy of keys and corresponding values.

  • def (bool = False) – default value to return if the specified key does not exist within the scope.

  • def

Return type

Tuple[bool, bool]

Returns

  • entry value as boolean from scope given its key

  • ok: set to True if key exists and has been successfully retrieved as a boolean

readDoubleEntry(self, scope: str, key: str, def_: float = 0) Tuple[float, bool]

Reads a double from the specified scope and key.

Parameters
  • scope (str) – entry scope (group) name

  • key (str) – entry key name. Keys are ‘/’-delimited entries, implying a hierarchy of keys and corresponding values.

  • def (float = 0) – default value to return if the specified key does not exist within the scope.

  • def

Return type

Tuple[float, bool]

Returns

  • entry value as double from scope given its key

  • ok: set to True if key exists and has been successfully retrieved as a double

readEntry(self, scope: str, key: str, def_: str = '') Tuple[str, bool]

Reads a string from the specified scope and key.

Parameters
  • scope (str) – entry scope (group) name

  • key (str) – entry key name. Keys are ‘/’-delimited entries, implying a hierarchy of keys and corresponding values.

  • def (str = '') – default value to return if the specified key does not exist within the scope.

  • def

Return type

Tuple[str, bool]

Returns

  • entry value as string from scope given its key

  • ok: set to True if key exists and has been successfully retrieved as a string value

readLayer(self, layerNode: QDomNode) bool

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 (QDomNode) – represents a QgsProject DOM node that encodes a specific layer.

Return type

bool

readListEntry(self, scope: str, key: str, def_: Iterable[str] = []) Tuple[List[str], bool]

Reads a string list from the specified scope and key.

Parameters
  • scope (str) – entry scope (group) name

  • key (str) – entry key name. Keys are ‘/’-delimited entries, implying a hierarchy of keys and corresponding values.

  • def (Iterable[str] = []) – default value to return if the specified key does not exist within the scope.

  • def

Return type

Tuple[List[str], bool]

Returns

  • entry value as a string list

  • ok: set to True if key exists and has been successfully retrieved as a string list

readMapLayer

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 (QgsMapLayer) – The map layer which is being initialized

  • layerNode (QDomElement) – The layer node from the project file [signal]

readNumEntry(self, scope: str, key: str, def_: int = 0) Tuple[int, bool]

Reads an integer from the specified scope and key.

Parameters
  • scope (str) – entry scope (group) name

  • key (str) – entry key name. Keys are ‘/’-delimited entries, implying a hierarchy of keys and corresponding values.

  • def (int = 0) – default value to return if the specified key does not exist within the scope.

  • def

Return type

Tuple[int, bool]

Returns

  • entry value as integer from scope given its key

  • ok: set to True if key exists and has been successfully retrieved as an integer

readPath(self, filename: str) str

Transforms a filename read from the project file to an absolute path.

Parameters

filename (str) –

Return type

str

readProject

Emitted when a project is being read. [signal]

readProjectWithContext

Emitted when a project is being read. And passing the /a context [signal]

Parameters
readVersionMismatchOccurred

Emitted when a project is read and the version of QGIS used to save the project differs from the current QGIS version.

The fileVersion argument indicates the version of QGIS used to save the project.

Note

Not available in Python bindings

New in version 3.26: [signal]

Parameters

fileVersion (str) –

receivers(self, PYQT_SIGNAL) int
registerTranslatableContainers(self, translationContext: QgsTranslationContext, parent: QgsAttributeEditorContainer, layerId: str)

Registers the containers that require translation into the translationContext. This is a recursive function to get all the child containers.

Parameters

New in version 3.4.

registerTranslatableObjects(self, translationContext: QgsTranslationContext)

Registers the objects that require translation into the translationContext. So there can be created a ts file with these values.

New in version 3.4.

Parameters

translationContext (QgsTranslationContext) –

relationManager(self) QgsRelationManager
Return type

QgsRelationManager

reloadAllLayers(self)

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

removeAll

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. [signal]

removeAllMapLayers(self)

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.

Note

Calling this method will cause the removeAll() signal to be emitted.

See also

removeMapLayer()

removeAttachedFile(self, path: str) bool

Removes the attached file

Parameters

path (str) – Path to the attached file

Return type

bool

Returns

Whether removal succeeded.

New in version 3.22.

removeEntry(self, scope: str, key: str) bool

Remove the given key from the specified scope.

Parameters
  • scope (str) –

  • key (str) –

Return type

bool

removeMapLayer(self, layerId: str)

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 (str) – ID of the layer to remove

Note

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

removeMapLayer(self, layer: QgsMapLayer) 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. None values are ignored.

Note

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

removeMapLayers(self, layerIds: Iterable[str])

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 (Iterable[str]) – list of IDs of the layers to remove

Note

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

See also

removeMapLayer()

New in version 1.8.

removeMapLayers(self, layers: Iterable[QgsMapLayer]) 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. None values are ignored.

Note

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

See also

removeMapLayer()

requiredLayers(self) Set[QgsMapLayer]

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 version QGIS: 3.4 use QgsMapLayer.flags() instead

New in version 3.2.

Return type

Set[QgsMapLayer]

resolveAttachmentIdentifier(self, identifier: str) str

Resolves an attachment identifier to a attachment file path

Parameters

identifier (str) – An attachment identifier

Return type

str

Returns

The attachment file path, or an empty string if the identifier is invalid

New in version 3.22.

saveUser(self) str

Returns the user name that did the last save.

New in version 3.12.

Return type

str

saveUserFullName(self) str

Returns the full user name that did the last save.

See also

saveUser()

New in version 3.12.

Return type

str

selectionColor(self) QColor

Returns the color used to highlight selected features

New in version 3.10.

Return type

QColor

selectionColorChanged

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

New in version 3.10: [signal]

sender(self) QObject
senderSignalIndex(self) int
setAreaUnits(self, unit: QgsUnitTypes.AreaUnit)

Sets the default area measurement units for the project.

See also

areaUnits()

New in version 3.0.

Parameters

unit (QgsUnitTypes.AreaUnit) –

setAutoTransaction(self, autoTransaction: bool)

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.

New in version 2.16.

Parameters

autoTransaction (bool) –

setAvoidIntersectionsLayers(self, layers: Iterable[QgsVectorLayer])

Sets the list of layers with which intersections should be avoided. Only used if the avoid intersection mode is set to advanced.

New in version 3.0.

Parameters

layers (Iterable[QgsVectorLayer]) –

setAvoidIntersectionsMode(self, mode: QgsProject.AvoidIntersectionsMode)

Sets the avoid intersections mode.

New in version 3.14.

Parameters

mode (QgsProject.AvoidIntersectionsMode) –

setBackgroundColor(self, color: Union[QColor, Qt.GlobalColor, QGradient])

Sets the default background color used by default map canvases.

New in version 3.10.

Parameters

color (Union[QColor) –

setBadLayerHandler(self, handler: QgsProjectBadLayerHandler)

Change handler for missing layers. Deletes old handler and takes ownership of the new one.

Parameters

handler (QgsProjectBadLayerHandler) –

setCrs(self, crs: QgsCoordinateReferenceSystem, adjustEllipsoid: bool = 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()

See also

setEllipsoid()

New in version 3.0.

Parameters
setCustomVariables(self, customVariables: Dict[str, Any])

A map of custom project variables. Be careful not to set generated variables.

Parameters

customVariables (Dict[str) –

setDataDefinedServerProperties(self, properties: QgsPropertyCollection)

Sets the data defined properties used for overrides in user defined server parameters to properties

New in version 3.14.

Parameters

properties (QgsPropertyCollection) –

setDirty(self, b: bool = True)

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

New in version 2.4.

Parameters

b (bool = True) –

setDistanceUnits(self, unit: QgsUnitTypes.DistanceUnit)

Sets the default distance measurement units for the project.

See also

distanceUnits()

See also

setAreaUnits()

New in version 3.0.

Parameters

unit (QgsUnitTypes.DistanceUnit) –

setEllipsoid(self, ellipsoid: str)

Sets the project’s ellipsoid from a proj string representation, e.g., “WGS84”.

See also

ellipsoid()

See also

setCrs()

New in version 3.0.

Parameters

ellipsoid (str) –

setEvaluateDefaultValues(self, evaluateDefaultValues: bool)

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

New in version 2.16.

Parameters

evaluateDefaultValues (bool) –

setFileName(self, name: str)

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 (str) – project file name

See also

fileName()

setFilePathStorage(self, type: Qgis.FilePathType)

Sets the type of paths used when storing file paths in a QGS/QGZ project file.

New in version 3.22.

Parameters

type (Qgis.FilePathType) –

setInstance(project: QgsProject)

Set the current project singleton instance to project

Note

this method is provided mainly for the server, which caches the projects and (potentially) needs to switch the current instance on every request.

Warning

calling this method can have serious, unintended consequences, including instability, data loss and undefined behavior. Use with EXTREME caution!

See also

instance()

New in version 3.10.11.

Parameters

project (QgsProject) –

setLabelingEngineSettings(self, settings: QgsLabelingEngineSettings)

Sets project’s global labeling engine settings

New in version 3.0.

Parameters

settings (QgsLabelingEngineSettings) –

setMapScales(self, scales: Iterable[float])

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()

Deprecated since version Use: viewSettings() instead

Parameters

scales (Iterable[float]) –

setMetadata(self, metadata: QgsProjectMetadata)

Sets the project’s metadata store.

See also

metadata()

New in version 3.2.

Parameters

metadata (QgsProjectMetadata) –

setNonIdentifiableLayers(self, layers: Iterable[QgsMapLayer])

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

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

setNonIdentifiableLayers(self, layerIds: Iterable[str]) Set a list of layers which should not be taken into account on map identification

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

Parameters

layers (Iterable[QgsMapLayer]) –

setOriginalPath(self, path: str)

Sets the original path associated with the project.

This is intended for use with non-qgs/qgz project files (see QgsCustomProjectOpenHandler) in order to allow custom project open handlers to specify the original file name of the project. For custom project formats, it is NOT appropriate to call setFileName() with the original project path, as this causes the original (non QGIS) project file to be overwritten when the project is next saved.

See also

originalPath()

New in version 3.14.

Parameters

path (str) –

setPresetHomePath(self, path: str)

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()

See also

homePath()

New in version 3.2.

Parameters

path (str) –

setProjectColors(self, colors: Iterable[Tuple[Union[QColor, Qt.GlobalColor, QGradient], str]])

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

New in version 3.6.

Parameters

colors (Iterable[Tuple[Union[QColor) –

setRequiredLayers(self, layers: Iterable[QgsMapLayer])

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 version QGIS: 3.4 use QgsMapLayer.setFlags() instead

New in version 3.2.

Parameters

layers (Iterable[QgsMapLayer]) –

setSelectionColor(self, color: Union[QColor, Qt.GlobalColor, QGradient])

Sets the color used to highlight selected features.

See also

selectionColor()

New in version 3.10.

Parameters

color (Union[QColor) –

setSnappingConfig(self, snappingConfig: QgsSnappingConfig)

The snapping configuration for this project.

New in version 3.0.

Parameters

snappingConfig (QgsSnappingConfig) –

setTitle(self, title: str)

Sets the project’s title.

Parameters

title (str) – new title

Note

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

See also

title()

New in version 2.4.

setTopologicalEditing(self, enabled: bool)

Convenience function to set topological editing

Parameters

enabled (bool) –

setTransformContext(self, context: QgsCoordinateTransformContext)

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.

New in version 3.0.

Parameters

context (QgsCoordinateTransformContext) –

setTrustLayerMetadata(self, trust: bool)

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 (bool) – True to trust the project, False otherwise

New in version 3.0.

setUseProjectScales(self, enabled: bool)

Sets whether project mapScales() are enabled.

See also

setMapScales()

Deprecated since version Use: viewSettings() instead

Parameters

enabled (bool) –

snappingConfig(self) QgsSnappingConfig

The snapping configuration for this project.

New in version 3.0.

Return type

QgsSnappingConfig

snappingConfigChanged

Emitted whenever the configuration for snapping has changed. [signal]

Parameters

config (QgsSnappingConfig) –

subkeyList(self, scope: str, key: str) List[str]

Returns a list of child keys which contain other keys that exist within the the specified scope and key.

This method only returns keys with keys, it will not return keys that contain only values. See entryList() to retrieve keys with values.

Note

equivalent to QgsSettings subkeyList()

Parameters
  • scope (str) –

  • key (str) –

Return type

List[str]

takeMapLayer(self, layer: QgsMapLayer) QgsMapLayer

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()

New in version 3.0.

Parameters

layer (QgsMapLayer) –

Return type

QgsMapLayer

timeSettings(self) QgsProjectTimeSettings

Returns the project’s time settings, which contains the project’s temporal range and other time based settings.

New in version 3.14.

Return type

QgsProjectTimeSettings

timerEvent(self, QTimerEvent)
title(self) str

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().

Return type

str

topologicalEditing(self) bool

Convenience function to query topological editing status

Return type

bool

topologicalEditingChanged

Emitted when the topological editing flag has changed.

New in version 3.0: [signal]

transactionGroup(self, providerKey: str, connString: str) QgsTransactionGroup

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

Returns None if a matching transaction group is not available.

New in version 3.2.

Parameters
  • providerKey (str) –

  • connString (str) –

Return type

QgsTransactionGroup

transactionGroupsChanged

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

New in version 3.0: [signal]

transformContext(self) QgsCoordinateTransformContext

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.

New in version 3.0.

Return type

QgsCoordinateTransformContext

transformContextChanged

Emitted when the project transformContext() is changed.

New in version 3.0: [signal]

translate(self, context: str, sourceText: str, disambiguation: str = None, n: int = -1) str

Translates the project with QTranslator and qm file

Return type

str

Returns

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

Parameters
  • context (str) – describing layer etc.

  • sourceText (str) – is the identifier of this text

  • disambiguation (str = None) – it’s the disambiguation

  • n (int = -1) – if -1 uses the appropriate form

New in version 3.4.

trustLayerMetadata(self) bool

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.

New in version 3.0.

Return type

bool

useProjectScales(self) bool

Returns True if project mapScales() are enabled.

See also

mapScales()

Deprecated since version Use: viewSettings() instead

Return type

bool

validCount(self) int

Returns the number of registered valid layers.

Return type

int

viewSettings(self) QgsProjectViewSettings

Returns the project’s view settings, which contains settings and properties relating to how a QgsProject should be viewed and behave inside a map canvas (e.g. map scales and default view extent)

New in version 3.10.1.

Return type

QgsProjectViewSettings

viewsManager(self) QgsMapViewsManager

Returns the project’s views manager, which manages map views (including 3d maps) in the project.

New in version 3.24.

Return type

QgsMapViewsManager

write(self, filename: str) bool

Writes the project to a file.

Parameters

filename (str) – destination file

Returns

True if project was written successfully

Note

calling this implicitly sets the project’s filename (see setFileName() )

Note

isDirty() will be set to False if project is successfully written

New in version 3.0.

write(self) -> bool Writes the project to its current associated file (see fileName() ).

Return type

bool

Returns

True if project was written successfully

Note

isDirty() will be set to False if project is successfully written

writeEntry(self, scope: str, key: str, value: int) bool

Write an integer value to the project file.

Keys are ‘/’-delimited entries, implying a hierarchy of keys and corresponding values

Note

The key string must be valid xml tag names in order to be saved to the file.

See also

readNumEntry()

writeEntry(self, scope: str, key: str, value: str) -> bool Write a string value to the project file.

Keys are ‘/’-delimited entries, implying a hierarchy of keys and corresponding values

Note

The key string must be valid xml tag names in order to be saved to the file.

See also

readEntry()

writeEntry(self, scope: str, key: str, value: Iterable[str]) -> bool Write a string list value to the project file.

Keys are ‘/’-delimited entries, implying a hierarchy of keys and corresponding values

Note

The key string must be valid xml tag names in order to be saved to the file.

See also

readListEntry()

Parameters
  • scope (str) –

  • key (str) –

  • value (int) –

Return type

bool

writeEntryBool(self, scope: str, key: str, value: bool) bool

Write a boolean value to the project file.

Keys are ‘/’-delimited entries, implying a hierarchy of keys and corresponding values

Note

The key string must be valid xml tag names in order to be saved to the file.

Note

available in Python bindings as writeEntryBool

See also

readBoolEntry()

Parameters
  • scope (str) –

  • key (str) –

  • value (bool) –

Return type

bool

writeEntryDouble(self, scope: str, key: str, value: float) bool

Write a double value to the project file.

Keys are ‘/’-delimited entries, implying a hierarchy of keys and corresponding values

Note

The key string must be valid xml tag names in order to be saved to the file.

Note

available in Python bindings as writeEntryDouble

Parameters
  • scope (str) –

  • key (str) –

  • value (float) –

Return type

bool

writeMapLayer

Emitted when a layer is being saved. You can use this method to save additional information to the layer.

Parameters
  • mapLayer (QgsMapLayer) – The map layer which is being initialized

  • layerElem (QDomElement) – The layer element from the project file

  • doc (QDomDocument) – The document [signal]

writePath(self, filename: str) str

Prepare a filename to save it to the project file. Creates an absolute or relative path according to the project settings. Paths written to the project file should be prepared with this method.

Parameters

filename (str) –

Return type

str

writeProject

Emitted when the project is being written. [signal]