Subgroup: Processing

Class: QgsProcessingParameterWidgetFactoryInterface

class qgis.gui.QgsProcessingParameterWidgetFactoryInterface

Bases: sip.wrapper

An interface for Processing widget wrapper factories.

Widget wrapper factories allow creation of QgsAbstractProcessingParameterWidgetWrapper objects. They are centrally managed by QgsProcessingGuiRegistry. Usually, individual factories are not directly utilized, rather the QgsGui.processingGuiRegistry()->createParameterWidgetWrapper() method is used to create widget wrappers.

New in version 3.4: Methods

compatibleDataTypes Returns a list of compatible Processing data types for inputs for this parameter.
compatibleOutputTypes Returns a list of compatible Processing output types for inputs for this parameter.
compatibleParameterTypes Returns a list of compatible Processing parameter types for inputs for this parameter.
createModelerWidgetWrapper Creates a new modeler parameter widget for the given parameter.
createWidgetWrapper Creates a new widget wrapper for the specified parameter definition.
modelerExpressionFormatString Returns the expected expression format string for expression results for the parameter within model child algorithms.
parameterType Returns the type string for the parameter type the factory is associated with.

Signals

Attributes

compatibleDataTypes(self) → List[int]

Returns a list of compatible Processing data types for inputs for this parameter.

In order to determine the available sources for the parameter in a model the types returned by this method are checked. The returned list corresponds to the various available values from QgsProcessing.SourceType.

Subclasses should return a list of all QgsProcessing.SourceType values which can be used as values for the parameter.

compatibleOutputTypes(self) → List[str]

Returns a list of compatible Processing output types for inputs for this parameter.

In order to determine the available sources for the parameter in a model the types returned by this method are checked. The returned list corresponds to the various available values for QgsProcessingOutputDefinition.type()

Subclasses should return a list of all QgsProcessingOutputDefinition.type() values which can be used as values for the parameter.

compatibleParameterTypes(self) → List[str]

Returns a list of compatible Processing parameter types for inputs for this parameter.

In order to determine the available sources for the parameter in a model the types returned by this method are checked. The returned list corresponds to the various available values for QgsProcessingParameterDefinition.type()

Subclasses should return a list of all QgsProcessingParameterDefinition.type() values which can be used as input values for the parameter.

createModelerWidgetWrapper(self, model: QgsProcessingModelAlgorithm, childId: str, parameter: QgsProcessingParameterDefinition, context: QgsProcessingContext) → QgsProcessingModelerParameterWidget

Creates a new modeler parameter widget for the given parameter. This widget allows configuration of the parameter’s value when used inside a Processing model.

The ID of the child algorithm within the model must be specified via the childId argument. This value corresponds to the QgsProcessingModelChildAlgorithm.childId() string, which uniquely identifies which child algorithm the parameter is associated with inside the given model.

A Processing context must also be specified, which allows the widget to resolve parameter values which are context dependent. The context must last for the lifetime of the widget.

createWidgetWrapper(self, parameter: QgsProcessingParameterDefinition, type: QgsProcessingGui.WidgetType) → QgsAbstractProcessingParameterWidgetWrapper

Creates a new widget wrapper for the specified parameter definition.

The type argument indicates the dialog type to create a wrapper for.

modelerExpressionFormatString(self) → str

Returns the expected expression format string for expression results for the parameter within model child algorithms.

This is shown in modeler widget wrappers when using the “pre-calculated” expression mode, and should give helpful text to users to indicate the expected results from the expression.

This is purely a text format and no expression validation is made against it.

parameterType(self) → str

Returns the type string for the parameter type the factory is associated with.