Contains information about the context in which a processing algorithm is executed. More...

#include <qgsprocessingcontext.h>

Classes
class	LayerDetails
	Details for layers to load into projects. More...

Public Types
enum	Flag
	Flags that affect how processing algorithms are run. More...

Public Member Functions
	QgsProcessingContext ()
	Constructor for QgsProcessingContext. More...

	QgsProcessingContext (const QgsProcessingContext &other)=delete
	QgsProcessingContext cannot be copied. More...

	~QgsProcessingContext ()

void	addLayerToLoadOnCompletion (const QString &layer, const QgsProcessingContext::LayerDetails &details)
	Adds a layer to load (by ID or datasource) into the canvas upon completion of the algorithm or model. More...

void	copyThreadSafeSettings (const QgsProcessingContext &other)
	Copies all settings which are safe for use across different threads from other to this context. More...

QString	defaultEncoding () const
	Returns the default encoding to use for newly created files. More...

QgsExpressionContext &	expressionContext ()
	Returns the expression context. More...

const QgsExpressionContext &	expressionContext () const
	Returns the expression context. More...

QgsProcessingFeedback *	feedback ()
	Returns the associated feedback object. More...

QgsProcessingContext::Flags	flags () const
	Returns any flags set in the context. More...

QgsMapLayer *	getMapLayer (const QString &identifier)
	Returns a map layer from the context with a matching identifier. More...

std::function< void(const QgsFeature &) >	invalidGeometryCallback () const
	Returns the callback function to use when encountering an invalid geometry and invalidGeometryCheck() is set to GeometryAbortOnInvalid. More...

QgsFeatureRequest::InvalidGeometryCheck	invalidGeometryCheck () const
	Returns the behavior used for checking invalid geometries in input layers. More...

QMap< QString, QgsProcessingContext::LayerDetails >	layersToLoadOnCompletion () const
	Returns a map of layers (by ID or datasource) to LayerDetails, to load into the canvas upon completion of the algorithm or model. More...

QgsProcessingContext::LayerDetails &	layerToLoadOnCompletionDetails (const QString &layer)
	Returns a reference to the details for a given layer which is loaded on completion of the algorithm or model. More...

QgsProcessingContext &	operator= (const QgsProcessingContext &other)=delete
	QgsProcessingContext cannot be copied. More...

QgsProject *	project () const
	Returns the project in which the algorithm is being executed. More...

void	pushToThread (QThread *thread)
	Pushes the thread affinity for the context (including all layers contained in the temporaryLayerStore()) into another thread. More...

void	setDefaultEncoding (const QString &encoding)
	Sets the default encoding to use for newly created files. More...

void	setExpressionContext (const QgsExpressionContext &context)
	Sets the expression context. More...

void	setFeedback (QgsProcessingFeedback *feedback)
	Sets an associated feedback object. More...

void	setFlags (QgsProcessingContext::Flags flags)
	Sets flags for the context. More...

void	setInvalidGeometryCallback (const std::function< void(const QgsFeature &) > &callback)
	Sets a callback function to use when encountering an invalid geometry and invalidGeometryCheck() is set to GeometryAbortOnInvalid. More...

void	setInvalidGeometryCheck (QgsFeatureRequest::InvalidGeometryCheck check)
	Sets the behavior used for checking invalid geometries in input layers. More...

void	setLayersToLoadOnCompletion (const QMap< QString, QgsProcessingContext::LayerDetails > &layers)
	Sets the map of layers (by ID or datasource) to LayerDetails, to load into the canvas upon completion of the algorithm or model. More...

void	setProject (QgsProject *project)
	Sets the project in which the algorithm will be executed. More...

void	setTransformContext (const QgsCoordinateTransformContext &context)
	Sets the coordinate transform context. More...

void	setTransformErrorCallback (const std::function< void(const QgsFeature &) > &callback)
	Sets a callback function to use when encountering a transform error when iterating features. More...

QgsMapLayer *	takeResultLayer (const QString &id)
	Takes the result map layer with matching id from the context and transfers ownership of it back to the caller. More...

void	takeResultsFrom (QgsProcessingContext &context)
	Takes the results from another context and merges them with the results currently stored in this context. More...

QgsMapLayerStore *	temporaryLayerStore ()
	Returns a reference to the layer store used for storing temporary layers during algorithm execution. More...

QThread *	thread ()
	Returns the thread in which the context lives. More...

QgsCoordinateTransformContext	transformContext () const
	Returns the coordinate transform context. More...

std::function< void(const QgsFeature &) >	transformErrorCallback () const
	Returns the callback function to use when encountering a transform error when iterating features. More...

bool	willLoadLayerOnCompletion (const QString &layer) const
	Returns true if the given layer (by ID or datasource) will be loaded into the current project upon completion of the algorithm or model. More...

Detailed Description

Contains information about the context in which a processing algorithm is executed.

Contextual information includes settings such as the associated project, and expression context.

Since: QGIS 3.0

Definition at line 43 of file qgsprocessingcontext.h.

Member Enumeration Documentation

enum QgsProcessingContext::Flag

Flags that affect how processing algorithms are run.

Definition at line 48 of file qgsprocessingcontext.h.

Constructor & Destructor Documentation

QgsProcessingContext::QgsProcessingContext ( )

inline

Constructor for QgsProcessingContext.

Definition at line 57 of file qgsprocessingcontext.h.

QgsProcessingContext::QgsProcessingContext ( const QgsProcessingContext & other )

delete

QgsProcessingContext cannot be copied.

QgsProcessingContext::~QgsProcessingContext ( )

Definition at line 21 of file qgsprocessingcontext.cpp.

Member Function Documentation

void QgsProcessingContext::addLayerToLoadOnCompletion	(	const QString &	layer,
		const QgsProcessingContext::LayerDetails &	details
	)

Adds a layer to load (by ID or datasource) into the canvas upon completion of the algorithm or model.

The details parameter dictates the LayerDetails.

See also: setLayersToLoadOnCompletion(); layersToLoadOnCompletion(); willLoadLayerOnCompletion(); layerToLoadOnCompletionDetails()

Definition at line 39 of file qgsprocessingcontext.cpp.

void QgsProcessingContext::copyThreadSafeSettings ( const QgsProcessingContext & other )

inline

Copies all settings which are safe for use across different threads from other to this context.

Definition at line 78 of file qgsprocessingcontext.h.

QString QgsProcessingContext::defaultEncoding ( ) const

inline

Returns the default encoding to use for newly created files.

See also: setDefaultEncoding()

Definition at line 372 of file qgsprocessingcontext.h.

QgsExpressionContext& QgsProcessingContext::expressionContext ( )

inline

Returns the expression context.

Definition at line 127 of file qgsprocessingcontext.h.

const QgsExpressionContext& QgsProcessingContext::expressionContext ( ) const

inline

Returns the expression context.

Definition at line 132 of file qgsprocessingcontext.h.

QgsProcessingFeedback* QgsProcessingContext::feedback ( )

inline

Returns the associated feedback object.

See also: setFeedback()

Definition at line 384 of file qgsprocessingcontext.h.

QgsProcessingContext::Flags QgsProcessingContext::flags ( ) const

inline

Returns any flags set in the context.

See also: setFlags()

Definition at line 95 of file qgsprocessingcontext.h.

QgsMapLayer * QgsProcessingContext::getMapLayer ( const QString & identifier )

Returns a map layer from the context with a matching identifier.

This method considers layer IDs, names and sources when matching the identifier (see QgsProcessingUtils::mapLayerFromString() for details).

Ownership is not transferred and remains with the context.

See also: takeResultLayer()

Definition at line 86 of file qgsprocessingcontext.cpp.

std::function< void( const QgsFeature & ) > QgsProcessingContext::invalidGeometryCallback ( ) const

inline

Returns the callback function to use when encountering an invalid geometry and invalidGeometryCheck() is set to GeometryAbortOnInvalid.

Note: not available in Python bindings

See also: setInvalidGeometryCallback()

Since: QGIS 3.0

Definition at line 332 of file qgsprocessingcontext.h.

QgsFeatureRequest::InvalidGeometryCheck QgsProcessingContext::invalidGeometryCheck ( ) const

inline

Returns the behavior used for checking invalid geometries in input layers.

See also: setInvalidGeometryCheck()

Definition at line 290 of file qgsprocessingcontext.h.

QMap< QString, QgsProcessingContext::LayerDetails > QgsProcessingContext::layersToLoadOnCompletion ( ) const

inline

Returns a map of layers (by ID or datasource) to LayerDetails, to load into the canvas upon completion of the algorithm or model.

See also: setLayersToLoadOnCompletion(); addLayerToLoadOnCompletion(); willLoadLayerOnCompletion(); layerToLoadOnCompletionDetails()

Definition at line 230 of file qgsprocessingcontext.h.

QgsProcessingContext::LayerDetails& QgsProcessingContext::layerToLoadOnCompletionDetails ( const QString & layer )

inline

Returns a reference to the details for a given layer which is loaded on completion of the algorithm or model.

Warning: First check willLoadLayerOnCompletion(), or calling this method will incorrectly add layer as a layer to load on completion.

See also: willLoadLayerOnCompletion(); addLayerToLoadOnCompletion(); setLayersToLoadOnCompletion(); layersToLoadOnCompletion()

Since: QGIS 3.2

Definition at line 281 of file qgsprocessingcontext.h.

QgsProcessingContext& QgsProcessingContext::operator= ( const QgsProcessingContext & other )

delete

QgsProcessingContext cannot be copied.

QgsProject* QgsProcessingContext::project ( ) const

inline

Returns the project in which the algorithm is being executed.

See also: setProject()

Definition at line 107 of file qgsprocessingcontext.h.

void QgsProcessingContext::pushToThread ( QThread * thread )

inline

Pushes the thread affinity for the context (including all layers contained in the temporaryLayerStore()) into another thread.

This method is only safe to call when the current thread matches the existing thread affinity for the context (see thread()).

See also: thread()

Definition at line 408 of file qgsprocessingcontext.h.

void QgsProcessingContext::setDefaultEncoding ( const QString & encoding )

inline

Sets the default encoding to use for newly created files.

See also: defaultEncoding()

Definition at line 378 of file qgsprocessingcontext.h.

void QgsProcessingContext::setExpressionContext ( const QgsExpressionContext & context )

inline

Sets the expression context.

Definition at line 137 of file qgsprocessingcontext.h.

void QgsProcessingContext::setFeedback ( QgsProcessingFeedback * feedback )

inline

Sets an associated feedback object.

This allows context related functions to report feedback and errors to users and processing logs. While ideally this feedback object should outlive the context, only a weak pointer to feedback is stored and no errors will occur if feedback is deleted before the context. Ownership of feedback is not transferred.

See also: setFeedback()

Definition at line 394 of file qgsprocessingcontext.h.

void QgsProcessingContext::setFlags ( QgsProcessingContext::Flags flags )

inline

Sets flags for the context.

See also: flags()

Definition at line 101 of file qgsprocessingcontext.h.

void QgsProcessingContext::setInvalidGeometryCallback ( const std::function< void(const QgsFeature &) > & callback )

inline

Sets a callback function to use when encountering an invalid geometry and invalidGeometryCheck() is set to GeometryAbortOnInvalid.

This function will be called using the feature with invalid geometry as a parameter.

See also: invalidGeometryCallback()

Since: QGIS 3.0

Definition at line 308 of file qgsprocessingcontext.h.

void QgsProcessingContext::setInvalidGeometryCheck ( QgsFeatureRequest::InvalidGeometryCheck check )

Sets the behavior used for checking invalid geometries in input layers.

Settings this to anything but QgsFeatureRequest::GeometryNoCheck will also reset the invalidGeometryCallback() to a default implementation.

See also: invalidGeometryCheck()

Definition at line 47 of file qgsprocessingcontext.cpp.

void QgsProcessingContext::setLayersToLoadOnCompletion ( const QMap< QString, QgsProcessingContext::LayerDetails > & layers )

Sets the map of layers (by ID or datasource) to LayerDetails, to load into the canvas upon completion of the algorithm or model.

See also: addLayerToLoadOnCompletion(); layersToLoadOnCompletion(); willLoadLayerOnCompletion(); layerToLoadOnCompletionDetails()

Definition at line 29 of file qgsprocessingcontext.cpp.

void QgsProcessingContext::setProject ( QgsProject * project )

inline

Sets the project in which the algorithm will be executed.

This also automatically sets the transformContext() to match the project's transform context.

See also: project()

Definition at line 117 of file qgsprocessingcontext.h.

void QgsProcessingContext::setTransformContext ( const QgsCoordinateTransformContext & context )

inline

Sets the coordinate transform context.

Note that setting a project for the context will automatically set the coordinate transform context.

See also: transformContext()

Definition at line 153 of file qgsprocessingcontext.h.

void QgsProcessingContext::setTransformErrorCallback ( const std::function< void(const QgsFeature &) > & callback )

inline

Sets a callback function to use when encountering a transform error when iterating features.

This function will be called using the feature which encountered the transform error as a parameter.

See also: transformErrorCallback()

Since: QGIS 3.0

Definition at line 342 of file qgsprocessingcontext.h.

QgsMapLayer * QgsProcessingContext::takeResultLayer ( const QString & id )

Takes the result map layer with matching id from the context and transfers ownership of it back to the caller.

This method can be used to remove temporary layers which are not required for further processing from a context.

See also: getMapLayer()

Definition at line 91 of file qgsprocessingcontext.cpp.

void QgsProcessingContext::takeResultsFrom ( QgsProcessingContext & context )

Takes the results from another context and merges them with the results currently stored in this context.

This includes settings like any layers loaded in the temporaryLayerStore() and layersToLoadOnCompletion(). This is only safe to call when both this context and the other context share the same thread() affinity, and that thread is the current thread.

Definition at line 79 of file qgsprocessingcontext.cpp.

QgsMapLayerStore* QgsProcessingContext::temporaryLayerStore ( )

inline

Returns a reference to the layer store used for storing temporary layers during algorithm execution.

Definition at line 159 of file qgsprocessingcontext.h.

QThread* QgsProcessingContext::thread ( )

inline

Returns the thread in which the context lives.

See also: pushToThread()

Definition at line 400 of file qgsprocessingcontext.h.

QgsCoordinateTransformContext QgsProcessingContext::transformContext ( ) const

inline

Returns the coordinate transform context.

See also: setTransformContext()

Definition at line 143 of file qgsprocessingcontext.h.

std::function< void( const QgsFeature & ) > QgsProcessingContext::transformErrorCallback ( ) const

inline

Returns the callback function to use when encountering a transform error when iterating features.

Note: not available in Python bindings

See also: setTransformErrorCallback()

Since: QGIS 3.0

Definition at line 366 of file qgsprocessingcontext.h.

bool QgsProcessingContext::willLoadLayerOnCompletion ( const QString & layer ) const

inline

Returns true if the given layer (by ID or datasource) will be loaded into the current project upon completion of the algorithm or model.

See also: layersToLoadOnCompletion(); setLayersToLoadOnCompletion(); addLayerToLoadOnCompletion(); layerToLoadOnCompletionDetails()

Since: QGIS 3.2

Definition at line 244 of file qgsprocessingcontext.h.

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

/build/qgis-3.4.15+24xenial/src/core/processing/qgsprocessingcontext.h
/build/qgis-3.4.15+24xenial/src/core/processing/qgsprocessingcontext.cpp

Classes

Public Types

Public Member Functions

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation