Abstract base class for processing providers. More...

#include <qgsprocessingprovider.h>

Inheritance diagram for QgsProcessingProvider:

Public Types
enum	Flag { FlagDeemphasiseSearchResults = 1 << 1 }
	Flags indicating how and when an provider operates and should be exposed to users. More...

Signals
void	algorithmsLoaded ()
	Emitted when the provider has loaded (or refreshed) its list of available algorithms. More...

Public Member Functions
	QgsProcessingProvider (const QgsProcessingProvider &other)=delete
	Providers cannot be copied. More...

	QgsProcessingProvider (QObject *parent=nullptr)
	Constructor for QgsProcessingProvider. More...

	~QgsProcessingProvider () override

const QgsProcessingAlgorithm *	algorithm (const QString &name) const
	Returns the matching algorithm by name, or `nullptr` if no matching algorithm is contained by this provider. More...

QList< const QgsProcessingAlgorithm * >	algorithms () const
	Returns a list of algorithms supplied by this provider. More...

virtual bool	canBeActivated () const
	Returns `true` if the provider can be activated, or `false` if it cannot be activated (e.g. More...

virtual QString	defaultRasterFileExtension () const
	Returns the default file extension to use for raster outputs created by the provider. More...

virtual QString	defaultVectorFileExtension (bool hasGeometry=true) const
	Returns the default file extension to use for vector outputs created by the provider. More...

virtual Flags	flags () const
	Returns the flags indicating how and when the provider operates and should be exposed to users. More...

virtual QString	helpId () const
	Returns the provider help id string, used for creating QgsHelp urls for algorithms belong to this provider. More...

virtual QIcon	icon () const
	Returns an icon for the provider. More...

virtual QString	id () const =0
	Returns the unique provider id, used for identifying the provider. More...

virtual bool	isActive () const
	Returns `true` if the provider is active and able to run algorithms. More...

virtual bool	isSupportedOutputValue (const QVariant &outputValue, const QgsProcessingDestinationParameter *parameter, QgsProcessingContext &context, QString &error) const
	Returns `true` if the specified outputValue is of a supported file format for the given destination parameter. More...

virtual bool	load ()
	Loads the provider. More...

virtual QString	longName () const
	Returns the longer version of the provider name, which can include extra details such as version numbers. More...

virtual QString	name () const =0
	Returns the provider name, which is used to describe the provider within the GUI. More...

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

void	refreshAlgorithms ()
	Refreshes the algorithms available from the provider, causing it to re-populate with all associated algorithms. More...

virtual QStringList	supportedOutputRasterLayerExtensions () const
	Returns a list of the raster format file extensions supported by this provider. More...

virtual QStringList	supportedOutputTableExtensions () const
	Returns a list of the table (geometry-less vector layers) file extensions supported by this provider. More...

virtual QStringList	supportedOutputVectorLayerExtensions () const
	Returns a list of the vector format file extensions supported by this provider. More...

virtual bool	supportsNonFileBasedOutput () const
	Returns `true` if the provider supports non-file based outputs (such as memory layers or direct database outputs). More...

virtual QString	svgIconPath () const
	Returns a path to an SVG version of the provider's icon. More...

virtual void	unload ()
	Unloads the provider. More...

virtual QString	versionInfo () const
	Returns a version information string for the provider, or an empty string if this is not applicable (e.g. More...

virtual QString	warningMessage () const
	Returns an optional warning message to show users when running algorithms from this provider. More...

Protected Member Functions
bool	addAlgorithm (QgsProcessingAlgorithm *algorithm)
	Adds an algorithm to the provider. More...

virtual void	loadAlgorithms ()=0
	Loads all algorithms belonging to this provider. More...

Detailed Description

Abstract base class for processing providers.

An algorithm provider is a set of related algorithms, typically from the same external application or related to a common area of analysis.

Since: QGIS 3.0

Definition at line 35 of file qgsprocessingprovider.h.

Member Enumeration Documentation

◆ Flag

enum QgsProcessingProvider::Flag

Flags indicating how and when an provider operates and should be exposed to users.

Since: QGIS 3.14

Enumerator
FlagDeemphasiseSearchResults	Algorithms should be de-emphasised in the search results when searching for algorithms. Use for low-priority providers or those with substantial known issues.

Definition at line 45 of file qgsprocessingprovider.h.

Constructor & Destructor Documentation

◆ QgsProcessingProvider() [1/2]

QgsProcessingProvider::QgsProcessingProvider ( QObject * parent = nullptr )

Constructor for QgsProcessingProvider.

Definition at line 24 of file qgsprocessingprovider.cpp.

◆ ~QgsProcessingProvider()

QgsProcessingProvider::~QgsProcessingProvider ( )

override

Definition at line 29 of file qgsprocessingprovider.cpp.

◆ QgsProcessingProvider() [2/2]

QgsProcessingProvider::QgsProcessingProvider ( const QgsProcessingProvider & other )

delete

Providers cannot be copied.

Member Function Documentation

◆ addAlgorithm()

bool QgsProcessingProvider::addAlgorithm ( QgsProcessingAlgorithm * algorithm )

protected

Adds an algorithm to the provider.

Ownership of the algorithm is transferred to the provider.

Definition at line 90 of file qgsprocessingprovider.cpp.

◆ algorithm()

const QgsProcessingAlgorithm * QgsProcessingProvider::algorithm ( const QString & name ) const

Returns the matching algorithm by name, or nullptr if no matching algorithm is contained by this provider.

See also: algorithms()

Definition at line 85 of file qgsprocessingprovider.cpp.

◆ algorithms()

QList< const QgsProcessingAlgorithm * > QgsProcessingProvider::algorithms ( ) const

Returns a list of algorithms supplied by this provider.

See also: algorithm()

Definition at line 80 of file qgsprocessingprovider.cpp.

◆ algorithmsLoaded

void QgsProcessingProvider::algorithmsLoaded ( )

signal

Emitted when the provider has loaded (or refreshed) its list of available algorithms.

See also: refreshAlgorithms()

◆ canBeActivated()

virtual bool QgsProcessingProvider::canBeActivated ( ) const

inlinevirtual

Returns true if the provider can be activated, or false if it cannot be activated (e.g.

due to missing external dependencies).

See also: isActive()

Definition at line 134 of file qgsprocessingprovider.h.

◆ defaultRasterFileExtension()

QString QgsProcessingProvider::defaultRasterFileExtension ( ) const

virtual

Returns the default file extension to use for raster outputs created by the provider.

The default implementation returns the user's default Processing raster output format setting, if it's supported by the provider (see supportedOutputRasterLayerExtensions()). Otherwise the first reported supported raster format will be used.

See also: supportedOutputRasterLayerExtensions(); defaultVectorFileExtension()

Definition at line 217 of file qgsprocessingprovider.cpp.

◆ defaultVectorFileExtension()

QString QgsProcessingProvider::defaultVectorFileExtension ( bool hasGeometry = true ) const

virtual

Returns the default file extension to use for vector outputs created by the provider.

If hasGeometry is true then the output file format must have support for geometry. If hasGeometry is false then non-spatial formats can be used.

The default implementation returns the user's default Processing vector output format setting, if it's supported by the provider (see supportedOutputVectorLayerExtensions()). Otherwise the first reported supported vector format will be used.

See also: supportedOutputVectorLayerExtensions(); defaultRasterFileExtension()

Definition at line 194 of file qgsprocessingprovider.cpp.

◆ flags()

QgsProcessingProvider::Flags QgsProcessingProvider::flags ( ) const

virtual

Returns the flags indicating how and when the provider operates and should be exposed to users.

Default is no flags.

Since: QGIS 3.14

Definition at line 44 of file qgsprocessingprovider.cpp.

◆ helpId()

QString QgsProcessingProvider::helpId ( ) const

virtual

Returns the provider help id string, used for creating QgsHelp urls for algorithms belong to this provider.

By default, this returns an empty string, meaning that no QgsHelp url should be created for the provider's algorithms.

See also: id()

Reimplemented in QgsNativeAlgorithms.

Definition at line 49 of file qgsprocessingprovider.cpp.

◆ icon()

QIcon QgsProcessingProvider::icon ( ) const

virtual

Returns an icon for the provider.

See also: svgIconPath()

Reimplemented in QgsNativeAlgorithms.

Definition at line 34 of file qgsprocessingprovider.cpp.

◆ id()

virtual QString QgsProcessingProvider::id ( ) const

pure virtual

Returns the unique provider id, used for identifying the provider.

This string should be a unique, short, character only string, eg "qgis" or "gdal". This string should not be localised.

See also: name(); helpId()

Implemented in QgsNativeAlgorithms.

◆ isActive()

virtual bool QgsProcessingProvider::isActive ( ) const

inlinevirtual

Returns true if the provider is active and able to run algorithms.

Definition at line 151 of file qgsprocessingprovider.h.

◆ isSupportedOutputValue()

bool QgsProcessingProvider::isSupportedOutputValue	(	const QVariant &	outputValue,
		const QgsProcessingDestinationParameter *	parameter,
		QgsProcessingContext &	context,
		QString &	error
	)		const

virtual

Returns true if the specified outputValue is of a supported file format for the given destination parameter.

If the output value is not supported, error will be set to a descriptive message explaining why.

Since: QGIS 3.6

Definition at line 120 of file qgsprocessingprovider.cpp.

◆ load()

virtual bool QgsProcessingProvider::load ( )

inlinevirtual

Loads the provider.

This will be called when the plugin is being loaded, and any general setup actions should occur in an overridden version of this method. Subclasses should not individually load any algorithms in their load() implementations, as that must occur within the loadAlgorithms() method. Instead, subclasses should call refreshAlgorithms() from any overloaded load() method to trigger an initial load of the provider's algorithms.

Returns: true if provider could be successfully loaded

See also: unload()

Definition at line 245 of file qgsprocessingprovider.h.

◆ loadAlgorithms()

virtual void QgsProcessingProvider::loadAlgorithms ( )

protectedpure virtual

Loads all algorithms belonging to this provider.

Subclasses should implement this, calling addAlgorithm() to register all their associated algorithms.

Implemented in QgsNativeAlgorithms.

◆ longName()

QString QgsProcessingProvider::longName ( ) const

virtual

Returns the longer version of the provider name, which can include extra details such as version numbers.

E.g. "Lastools LIDAR tools (version 2.2.1)". This string should be localised.

The default implementation returns the same string as name().

See also: name(); id()

Definition at line 54 of file qgsprocessingprovider.cpp.

◆ name()

virtual QString QgsProcessingProvider::name ( ) const

pure virtual

Returns the provider name, which is used to describe the provider within the GUI.

This string should be short (e.g. "Lastools") and localised.

See also: longName(); id()

Implemented in QgsNativeAlgorithms.

◆ operator=()

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

delete

Providers cannot be copied.

◆ refreshAlgorithms()

void QgsProcessingProvider::refreshAlgorithms ( )

Refreshes the algorithms available from the provider, causing it to re-populate with all associated algorithms.

Definition at line 69 of file qgsprocessingprovider.cpp.

◆ supportedOutputRasterLayerExtensions()

QStringList QgsProcessingProvider::supportedOutputRasterLayerExtensions ( ) const

virtual

Returns a list of the raster format file extensions supported by this provider.

See also: supportedOutputVectorLayerExtensions()

Definition at line 64 of file qgsprocessingprovider.cpp.

◆ supportedOutputTableExtensions()

QStringList QgsProcessingProvider::supportedOutputTableExtensions ( ) const

virtual

Returns a list of the table (geometry-less vector layers) file extensions supported by this provider.

By default this is the same as supportedOutputVectorLayerExtensions(). Providers which utilize different formats for geometry-less layers can override this method to return a different list of supported formats.

See also: supportedOutputVectorLayerExtensions(); defaultVectorFileExtension(); supportedOutputRasterLayerExtensions(); supportsNonFileBasedOutput()

Since: QGIS 3.4.3

Definition at line 115 of file qgsprocessingprovider.cpp.

◆ supportedOutputVectorLayerExtensions()

QStringList QgsProcessingProvider::supportedOutputVectorLayerExtensions ( ) const

virtual

Returns a list of the vector format file extensions supported by this provider.

See also: supportedOutputTableExtensions(); defaultVectorFileExtension(); supportedOutputRasterLayerExtensions(); supportsNonFileBasedOutput()

Definition at line 110 of file qgsprocessingprovider.cpp.

◆ supportsNonFileBasedOutput()

bool QgsProcessingProvider::supportsNonFileBasedOutput ( ) const

virtual

Returns true if the provider supports non-file based outputs (such as memory layers or direct database outputs).

If a provider returns false for this method than it indicates that none of the outputs from any of the provider's algorithms have support for non-file based outputs. Returning true indicates that the algorithm's parameters will each individually declare their non-file based support.

The default behavior for providers is to support non-file based outputs, and most providers which rely solely on QGIS API (and which do not depend on third-party scripts or external dependencies) will automatically support this.

See also: supportedOutputVectorLayerExtensions()

Reimplemented in QgsNativeAlgorithms.

Definition at line 239 of file qgsprocessingprovider.cpp.

◆ svgIconPath()

QString QgsProcessingProvider::svgIconPath ( ) const

virtual

Returns a path to an SVG version of the provider's icon.

See also: icon()

Reimplemented in QgsNativeAlgorithms.

Definition at line 39 of file qgsprocessingprovider.cpp.

◆ unload()

virtual void QgsProcessingProvider::unload ( )

inlinevirtual

Unloads the provider.

Any tear-down steps required by the provider should be implemented here.

See also: load()

Definition at line 251 of file qgsprocessingprovider.h.

◆ versionInfo()

QString QgsProcessingProvider::versionInfo ( ) const

virtual

Returns a version information string for the provider, or an empty string if this is not applicable (e.g.

for inbuilt Processing providers).

For plugin based providers, this should return the plugin's version identifier.

Since: QGIS 3.8

Definition at line 59 of file qgsprocessingprovider.cpp.

◆ warningMessage()

virtual QString QgsProcessingProvider::warningMessage ( ) const

inlinevirtual

Returns an optional warning message to show users when running algorithms from this provider.

This can be used to return a translated warning message which should be shown to users of this provider. It's intended for use in cases such as a provider which relies on a 3rd-party backend, where the version of the backend software is not officially supported, or for alerting users to providers in a "beta" or "untrustworthy" state.

Since: QGIS 3.10.1

Definition at line 146 of file qgsprocessingprovider.h.

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

/build/qgis-3.18.1+99unstable/src/core/processing/qgsprocessingprovider.h
/build/qgis-3.18.1+99unstable/src/core/processing/qgsprocessingprovider.cpp

Public Types

Signals

Public Member Functions

Protected Member Functions

Detailed Description

Member Enumeration Documentation

◆ Flag

Constructor & Destructor Documentation

◆ QgsProcessingProvider() [1/2]

◆ ~QgsProcessingProvider()

◆ QgsProcessingProvider() [2/2]

Member Function Documentation

◆ addAlgorithm()

◆ algorithm()

◆ algorithms()

◆ algorithmsLoaded

◆ canBeActivated()

◆ defaultRasterFileExtension()

◆ defaultVectorFileExtension()

◆ flags()

◆ helpId()

◆ icon()

◆ id()

◆ isActive()

◆ isSupportedOutputValue()

◆ load()

◆ loadAlgorithms()

◆ longName()

◆ name()

◆ operator=()

◆ refreshAlgorithms()

◆ supportedOutputRasterLayerExtensions()

◆ supportedOutputTableExtensions()

◆ supportedOutputVectorLayerExtensions()

◆ supportsNonFileBasedOutput()

◆ svgIconPath()

◆ unload()

◆ versionInfo()

◆ warningMessage()