Class: QgsProcessingRegistry

class qgis.core.QgsProcessingRegistry

Bases: PyQt5.QtCore.QObject

Registry for various processing components, including providers, algorithms and various parameters and outputs.

QgsProcessingRegistry is not usually directly created, but rather accessed through QgsApplication.processingRegistry().

New in version 3.0.

QgsProcessingRegistry(parent: QObject = None) Constructor for QgsProcessingRegistry.

Methods

addAlgorithmAlias

Adds a new alias to an existing algorithm.

addParameterType

Register a new parameter type for processing.

addProvider

Add a processing provider to the registry.

algorithmById

Finds an algorithm by its ID.

algorithms

Returns a list of all available algorithms from registered providers.

childEvent

connectNotify

createAlgorithmById

Creates a new instance of an algorithm by its ID.

customEvent

disconnectNotify

isSignalConnected

parameterType

Returns the parameter type registered for id.

parameterTypes

Returns a list with all known parameter types.

providerById

Returns a matching provider by provider ID.

providers

Gets list of available providers.

receivers

removeParameterType

Unregister a custom parameter type from processing.

removeProvider

Removes a provider implementation from the registry (the provider object is deleted).

sender

senderSignalIndex

timerEvent

Signals

parameterTypeAdded

Emitted when a new parameter type has been added to the registry.

parameterTypeRemoved

Emitted when a parameter type has been removed from the registry and is about to be deleted.

providerAdded

Emitted when a provider has been added to the registry.

providerRemoved

Emitted when a provider is removed from the registry [signal]

addAlgorithmAlias(self, aliasId: str, actualId: str)

Adds a new alias to an existing algorithm.

This allows algorithms to be referred to by a different provider ID and algorithm name to their actual underlying provider and algorithm name. It provides a mechanism to allow algorithms to be moved between providers without breaking existing scripts or plugins.

The aliasId argument specifies the “fake” algorithm id (eg “fake_provider:fake_alg”) by which the algorithm can be referred to, and the actualId argument specifies the real algorithm ID for the algorithm.

New in version 3.10.

Parameters
  • aliasId (str) –

  • actualId (str) –

addParameterType(self, type: QgsProcessingParameterType)bool

Register a new parameter type for processing. Ownership is transferred to the registry. Will emit parameterTypeAdded.

New in version 3.2.

Parameters

type (QgsProcessingParameterType) –

Return type

bool

addProvider(self, provider: QgsProcessingProvider)bool

Add a processing provider to the registry. Ownership of the provider is transferred to the registry, and the provider’s parent will be set to the registry. Returns False if the provider could not be added (eg if a provider with a duplicate ID already exists in the registry). Adding a provider to the registry automatically triggers the providers QgsProcessingProvider.load() method to populate the provider with algorithms.

See also

removeProvider()

Parameters

provider (QgsProcessingProvider) –

Return type

bool

algorithmById(self, id: str)QgsProcessingAlgorithm

Finds an algorithm by its ID. If no matching algorithm is found, None is returned.

See also

algorithms()

Parameters

id (str) –

Return type

QgsProcessingAlgorithm

algorithms(self)List[QgsProcessingAlgorithm]

Returns a list of all available algorithms from registered providers.

See also

algorithmById()

Return type

List[QgsProcessingAlgorithm]

childEvent(self, QChildEvent)
connectNotify(self, QMetaMethod)
createAlgorithmById(self, id: str, configuration: Dict[str, Any] = {})QgsProcessingAlgorithm

Creates a new instance of an algorithm by its ID. If no matching algorithm is found, None is returned. Callers take responsibility for deleting the returned object.

The configuration argument allows passing of a map of configuration settings to the algorithm, allowing it to dynamically adjust its initialized parameters and outputs according to this configuration. This is generally used only for algorithms in a model, allowing them to adjust their behavior at run time according to some user configuration.

See also

algorithms()

See also

algorithmById()

Parameters
  • id (str) –

  • configuration (Dict[str) –

Return type

QgsProcessingAlgorithm

customEvent(self, QEvent)
disconnectNotify(self, QMetaMethod)
isSignalConnected(self, QMetaMethod)bool
parameterType(self, id: str)QgsProcessingParameterType

Returns the parameter type registered for id.

New in version 3.2.

Parameters

id (str) –

Return type

QgsProcessingParameterType

parameterTypeAdded

Emitted when a new parameter type has been added to the registry.

New in version 3.2: [signal]

Parameters

type (QgsProcessingParameterType) –

parameterTypeRemoved

Emitted when a parameter type has been removed from the registry and is about to be deleted.

New in version 3.2: [signal]

Parameters

type (QgsProcessingParameterType) –

parameterTypes(self)List[QgsProcessingParameterType]

Returns a list with all known parameter types.

New in version 3.2.

Return type

List[QgsProcessingParameterType]

providerAdded

Emitted when a provider has been added to the registry. [signal]

Parameters

id (str) –

providerById(self, id: str)QgsProcessingProvider

Returns a matching provider by provider ID.

Parameters

id (str) –

Return type

QgsProcessingProvider

providerRemoved

Emitted when a provider is removed from the registry [signal]

Parameters

id (str) –

providers(self)List[QgsProcessingProvider]

Gets list of available providers.

Return type

List[QgsProcessingProvider]

receivers(self, PYQT_SIGNAL)int
removeParameterType(self, type: QgsProcessingParameterType)

Unregister a custom parameter type from processing. The type will be deleted. Will emit parameterTypeRemoved.

New in version 3.2.

Parameters

type (QgsProcessingParameterType) –

removeProvider(self, provider: QgsProcessingProvider)bool

Removes a provider implementation from the registry (the provider object is deleted). Returns False if the provider could not be removed (eg provider does not exist in the registry).

See also

addProvider()

removeProvider(self, providerId: str) -> bool Removes a provider implementation from the registry (the provider object is deleted). Returns False if the provider could not be removed (eg provider does not exist in the registry).

See also

addProvider()

Parameters

provider (QgsProcessingProvider) –

Return type

bool

sender(self)QObject
senderSignalIndex(self)int
timerEvent(self, QTimerEvent)