Class: QgsExpressionBuilderDialog

A generic dialog for building expression strings.

Class Hierarchy

Base classes

QDialog
QWidget
QObject
QPaintDevice

class qgis.gui.QgsExpressionBuilderDialog

Bases: QDialog

allowEvalErrors(self) → bool

Allow accepting invalid expressions. This can be useful when we are not able to provide an expression context of which we are sure it’s completely populated.

Return type:

bool

signal allowEvalErrorsChanged

pyqtSignal(*types, name: str = …, revision: int = …, arguments: Sequence = …) -> PYQT_SIGNAL

types is normally a sequence of individual types. Each type is either a type object or a string that is the name of a C++ type. Alternatively each type could itself be a sequence of types each describing a different overloaded signal. name is the optional C++ name of the signal. If it is not specified then the name of the class attribute that is bound to the signal is used. revision is the optional revision of the signal that is exported to QML. If it is not specified then 0 is used. arguments is the optional sequence of the names of the signal’s arguments.

virtual done(self, r: int)

Is called when the dialog get accepted or rejected Used to save geometry

Parameters:

r (int) – result value (unused)

expectedOutputFormat(self) → str

Returns the expected format string, which is shown in the dialog. This is purely a text format and no expression validation is done against it.

See also

setExpectedOutputFormat()

Return type:

str

expressionBuilder(self) → QgsExpressionBuilderWidget | None

The builder widget that is used by the dialog

Return type:

Optional[QgsExpressionBuilderWidget]

expressionContext(self) → QgsExpressionContext

Returns the expression context for the dialog. The context is used for the expression preview result and for populating the list of available functions and variables.

See also

setExpressionContext()

Return type:

QgsExpressionContext

expressionText(self) → str

Return type:

str

setAllowEvalErrors(self, allowEvalErrors: bool)

Allow accepting expressions with evaluation errors. This can be useful when we are not able to provide an expression context of which we are sure it’s completely populated.

Parameters:

allowEvalErrors (bool)

setExpectedOutputFormat(self, expected: str | None)

Set the expected format string, which is shown in the dialog. This is purely a text format and no expression validation is done against it.

See also

expectedOutputFormat()

Parameters:

expected (Optional[str])

setExpressionContext(self, context: QgsExpressionContext)

Sets the expression context for the dialog. The context is used for the expression preview result and for populating the list of available functions and variables.

Parameters:

context (QgsExpressionContext) – expression context

See also

expressionContext()

setExpressionText(self, text: str | None)

Parameters:

text (Optional[str])

setGeomCalculator(self, da: QgsDistanceArea)

Sets geometry calculator used in distance/area calculations.

Parameters:

da (QgsDistanceArea)