Class: QgsProcessingParameterExpression

class qgis.core.QgsProcessingParameterExpression

Bases: QgsProcessingParameterDefinition

An expression parameter for processing algorithms.

New in version 3.0.

QgsProcessingParameterExpression(name: str, description: str = ‘’, defaultValue: Any = None, parentLayerParameterName: str = ‘’, optional: bool = False) Constructor for QgsProcessingParameterExpression.

QgsProcessingParameterExpression(QgsProcessingParameterExpression)

Methods

asPythonString

param outputType:

clone

rtype:

QgsProcessingParameterDefinition

dependsOnOtherParameters

rtype:

List[str]

fromScriptCode

Creates a new parameter using the definition from a script code.

fromVariantMap

param map:

parentLayerParameterName

Returns the name of the parent layer parameter, or an empty string if this is not set.

setParentLayerParameterName

Sets the name of the parent layer parameter.

toVariantMap

rtype:

Dict[str, Any]

type

rtype:

str

typeName

Returns the type name for the parameter class.

valueAsPythonString

param value:

asPythonString(self, outputType: QgsProcessing.PythonOutputType = QgsProcessing.PythonQgsProcessingAlgorithmSubclass) str
Parameters:

outputType (QgsProcessing.PythonOutputType = QgsProcessing.PythonQgsProcessingAlgorithmSubclass) –

Return type:

str

clone(self) QgsProcessingParameterDefinition
Return type:

QgsProcessingParameterDefinition

dependsOnOtherParameters(self) List[str]
Return type:

List[str]

fromScriptCode(name: str, description: str, isOptional: bool, definition: str) QgsProcessingParameterExpression

Creates a new parameter using the definition from a script code.

Parameters:
  • name (str) –

  • description (str) –

  • isOptional (bool) –

  • definition (str) –

Return type:

QgsProcessingParameterExpression

fromVariantMap(self, map: Dict[str, Any]) bool
Parameters:

map (Dict[str) –

Return type:

bool

parentLayerParameterName(self) str

Returns the name of the parent layer parameter, or an empty string if this is not set.

Return type:

str

setParentLayerParameterName(self, parentLayerParameterName: str)

Sets the name of the parent layer parameter. Use an empty string if this is not required.

Parameters:

parentLayerParameterName (str) –

toVariantMap(self) Dict[str, Any]
Return type:

Dict[str, Any]

type(self) str
Return type:

str

typeName() str

Returns the type name for the parameter class.

Return type:

str

valueAsPythonString(self, value: Any, context: QgsProcessingContext) str
Parameters:
Return type:

str