Class: QgsScopedExpressionFunction

class qgis.core.QgsScopedExpressionFunction

Bases: QgsExpressionFunction

Expression function for use within a QgsExpressionContextScope. This differs from a standard QgsExpression.Function in that it requires an implemented clone() method.

QgsScopedExpressionFunction(fnname: str, params: int, group: str, helpText: str = ‘’, usesGeometry: bool = False, referencedColumns: Iterable[str] = set(), lazyEval: bool = False, handlesNull: bool = False, isContextual: bool = True) Create a new QgsScopedExpressionFunction

QgsScopedExpressionFunction(fnname: str, params: Iterable[QgsExpressionFunction.Parameter], group: str, helpText: str = ‘’, usesGeometry: bool = False, referencedColumns: Iterable[str] = set(), lazyEval: bool = False, handlesNull: bool = False, isContextual: bool = True) Create a new QgsScopedExpressionFunction using named parameters.

QgsScopedExpressionFunction(QgsScopedExpressionFunction)

Methods

allParamsStatic

This will return True if all the params for the provided function node are static within the constraints imposed by the context within the given parent.

clone

Returns a clone of the function.

func

param values:

isStatic

param node:

referencedColumns

param node:

usesGeometry

param node:

allParamsStatic(node: QgsExpressionNodeFunction, parent: QgsExpression, context: QgsExpressionContext) bool

This will return True if all the params for the provided function node are static within the constraints imposed by the context within the given parent.

This can be used as callback for custom implementations of subclasses. It is the default for implementation for StaticFunction.isStatic.

clone(self) QgsScopedExpressionFunction

Returns a clone of the function.

Return type:

QgsScopedExpressionFunction

func(self, values: Iterable[Any], context: QgsExpressionContext, parent: QgsExpression, node: QgsExpressionNodeFunction) Any
Parameters:
Return type:

Any

isStatic(self, node: QgsExpressionNodeFunction, parent: QgsExpression, context: QgsExpressionContext) bool
Parameters:
Return type:

bool

referencedColumns(self, node: QgsExpressionNodeFunction) Set[str]
Parameters:

node (QgsExpressionNodeFunction) –

Return type:

Set[str]

usesGeometry(self, node: QgsExpressionNodeFunction) bool
Parameters:

node (QgsExpressionNodeFunction) –

Return type:

bool