Class: QgsProcessingParameterExpression¶

An expression parameter for processing algorithms.

Class Hierarchy¶

Base classes¶

QgsProcessingParameterDefinition

Base class for the definition of processing parameters.

Methods

`expressionType`	Returns the parameter's expression type.
`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.

Static Methods

`fromScriptCode`	Creates a new parameter using the definition from a script code.
`typeName`	Returns the type name for the parameter class.

class qgis.core.QgsProcessingParameterExpression[source]¶

Bases: QgsProcessingParameterDefinition

__init__(name: str | None, description: str | None = '', defaultValue: Any = None, parentLayerParameterName: str | None = '', optional: bool = False, type: Qgis.ExpressionType = Qgis.ExpressionType.Qgis)

Constructor for QgsProcessingParameterExpression.

Parameters:

name (Optional[str])
description (Optional[str] = '')
defaultValue (Any = None)
parentLayerParameterName (Optional[str] = '')
optional (bool = False)
type (Qgis.ExpressionType = Qgis.ExpressionType.Qgis)

__init__(a0: QgsProcessingParameterExpression)

Parameters:: a0 (QgsProcessingParameterExpression)

expressionType(self) → Qgis.ExpressionType[source]¶

Returns the parameter’s expression type.

See also

setExpressionType()

Added in version 3.32.

Return type:: Qgis.ExpressionType

static fromScriptCode(name: str | None, description: str | None, isOptional: bool, definition: str | None) → QgsProcessingParameterExpression | None[source]¶

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

Parameters:

name (Optional[str])
description (Optional[str])
isOptional (bool)
definition (Optional[str])

Return type:

Optional[QgsProcessingParameterExpression]

parentLayerParameterName(self) → str[source]¶

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

See also

setParentLayerParameterName()

Return type:: str

setExpressionType(self, type: Qgis.ExpressionType)[source]¶

Sets the parameter’s expression type.

See also

expressionType()

Added in version 3.32.

Parameters:: type (Qgis.ExpressionType)

setParentLayerParameterName(self, parentLayerParameterName: str | None)[source]¶

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

See also

parentLayerParameterName()

Parameters:: parentLayerParameterName (Optional[str])

static typeName() → str[source]¶

Returns the type name for the parameter class.

Return type:: str