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, type: Qgis.ExpressionType = Qgis.ExpressionType.Qgis) Constructor for QgsProcessingParameterExpression.

QgsProcessingParameterExpression(QgsProcessingParameterExpression)

Methods

asPythonString

param outputType:

clone

rtype:

QgsProcessingParameterDefinition

dependsOnOtherParameters

rtype:

List[str]

expressionType

Returns the parameter's expression type.

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.

setExpressionType

Sets the parameter's expression type.

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]

expressionType(self) Qgis.ExpressionType

Returns the parameter’s expression type.

New in version 3.32.

Return type:

Qgis.ExpressionType

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

setExpressionType(self, type: Qgis.ExpressionType)

Sets the parameter’s expression type.

See also

expressionType()

New in version 3.32.

Parameters:

type (Qgis.ExpressionType) –

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