Class: QgsProcessingProvider

class qgis.core.QgsProcessingProvider(parent: QObject = None)

Bases: PyQt5.QtCore.QObject

Constructor for QgsProcessingProvider.

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.

New in version 3.0.

Parameters

parent

addAlgorithm(self, algorithm: QgsProcessingAlgorithm) → bool

Adds an algorithm to the provider. Ownership of the algorithm is transferred to the provider.

Parameters

algorithm (QgsProcessingAlgorithm) –

Return type

bool

algorithm(self, name: str)QgsProcessingAlgorithm

Returns the matching algorithm by name, or None if no matching algorithm is contained by this provider.

See also

algorithms()

Parameters

name (str) –

Return type

QgsProcessingAlgorithm

algorithms(self) → List[QgsProcessingAlgorithm]

Returns a list of algorithms supplied by this provider.

See also

algorithm()

Return type

List[QgsProcessingAlgorithm]

algorithmsLoaded

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

See also

refreshAlgorithms() [signal]

canBeActivated(self) → bool

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()

Return type

bool

childEvent(self, QChildEvent)
connectNotify(self, QMetaMethod)
customEvent(self, QEvent)
defaultRasterFileExtension(self) → str

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.

Return type

str

defaultVectorFileExtension(self, hasGeometry: bool = True) → str

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.

Parameters

hasGeometry (bool = True) –

Return type

str

disconnectNotify(self, QMetaMethod)
helpId(self) → str

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()

Return type

str

icon(self) → QIcon

Returns an icon for the provider.

See also

svgIconPath()

Return type

QIcon

id(self) → str

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()

See also

helpId()

Return type

str

isActive(self) → bool

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

Return type

bool

isSignalConnected(self, QMetaMethod) → bool
isSupportedOutputValue(self, outputValue: Any, parameter: QgsProcessingDestinationParameter, context: QgsProcessingContext) → Tuple[bool, str]

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.

New in version 3.6.

Parameters
Return type

Tuple[bool, str]

load(self) → bool

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.

Return type

bool

Returns

True if provider could be successfully loaded

See also

unload()

loadAlgorithms(self)

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

longName(self) → str

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()

See also

id()

Return type

str

name(self) → str

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()

See also

id()

Return type

str

receivers(self, PYQT_SIGNAL) → int
refreshAlgorithms(self)

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

sender(self) → QObject
senderSignalIndex(self) → int
supportedOutputRasterLayerExtensions(self) → List[str]

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

Return type

List[str]

supportedOutputTableExtensions(self) → List[str]

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.

New in version 3.4.3.

Return type

List[str]

supportedOutputVectorLayerExtensions(self) → List[str]

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

Return type

List[str]

supportsNonFileBasedOutput(self) → bool

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.

Return type

bool

svgIconPath(self) → str

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

See also

icon()

Return type

str

timerEvent(self, QTimerEvent)
unload(self)

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

See also

load()

versionInfo(self) → str

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.

New in version 3.8.

Return type

str

warningMessage(self) → str

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.

New in version 3.10.1.

Return type

str