Class: QgsAggregateMappingWidget

The QgsAggregateMappingWidget class creates a mapping for defining sets of aggregates of fields from a QgsFields object.

Added in version 3.14.

Class Hierarchy

Base classes

QgsPanelWidget	Base class for any widget that can be shown as a inline panel
QWidget
QObject
QPaintDevice

Methods

appendField	Appends a new field to the model, with an optional source and aggregate
mapping	Returns a list of Aggregate objects representing the current status of the underlying mapping model
model	Returns the underlying mapping model
moveSelectedFieldsDown	Moves down currently selected field
moveSelectedFieldsUp	Moves up currently selected field
registerExpressionContextGenerator	Register an expression context generator class that will be used to retrieve an expression context for the widget.
removeSelectedFields	Removes the currently selected field from the model
scrollTo	Scroll the fields view to index
selectionModel	Returns the selection model
setMapping	Sets the mapping to show in the model.
setSourceFields	Set source fields of the underlying mapping model to sourceFields
setSourceLayer	Sets a source layer to use when generating expression previews in the widget.
sourceLayer	Returns the source layer for use when generating expression previews.

Signals

changed

Emitted when the aggregates defined in the widget are changed.

class qgis.gui.QgsAggregateMappingWidget

Bases: QgsPanelWidget

__init__(parent: QWidget | None = None, sourceFields: QgsFields = QgsFields())

Constructs a QgsAggregateMappingWidget from a set of sourceFields. A parent object can also be specified.

Parameters:

• parent (Optional[QWidget] = None)

• sourceFields (QgsFields = QgsFields())

appendField(self, field: QgsField, source: str | None = '', aggregate: str | None = '')

Appends a new field to the model, with an optional source and aggregate

Parameters:

• field (QgsField)

• source (Optional[str] = '')

• aggregate (Optional[str] = '')

signal changed

Emitted when the aggregates defined in the widget are changed.

mapping(self) → List[QgsAggregateMappingModel.Aggregate]

Returns a list of Aggregate objects representing the current status of the underlying mapping model

Return type:

List[QgsAggregateMappingModel.Aggregate]

model(self) → QgsAggregateMappingModel | None

Returns the underlying mapping model

Return type:

Optional[QgsAggregateMappingModel]

moveSelectedFieldsDown(self) → bool

Moves down currently selected field

Return type:

bool

moveSelectedFieldsUp(self) → bool

Moves up currently selected field

Return type:

bool

registerExpressionContextGenerator(self, generator: QgsExpressionContextGenerator | None)

Register an expression context generator class that will be used to retrieve an expression context for the widget.

Parameters:

generator (Optional[QgsExpressionContextGenerator])

removeSelectedFields(self) → bool

Removes the currently selected field from the model

Return type:

bool

scrollTo(self, index: QModelIndex)

Scroll the fields view to index

Parameters:

index (QModelIndex)

selectionModel(self) → QItemSelectionModel | None

Returns the selection model

Return type:

Optional[QItemSelectionModel]

setMapping(self, mapping: Iterable[QgsAggregateMappingModel.Aggregate])

Sets the mapping to show in the model.

Parameters:

mapping (Iterable[QgsAggregateMappingModel.Aggregate])

setSourceFields(self, sourceFields: QgsFields)

Set source fields of the underlying mapping model to sourceFields

Parameters:

sourceFields (QgsFields)

setSourceLayer(self, layer: QgsVectorLayer | None)

Sets a source layer to use when generating expression previews in the widget.

Added in version 3.16.

Parameters:

layer (Optional[QgsVectorLayer])

sourceLayer(self) → QgsVectorLayer | None

Returns the source layer for use when generating expression previews.

Returned value may be None.

Added in version 3.16.

Return type:

Optional[QgsVectorLayer]