Class: QgsFieldComboBox¶

The QgsFieldComboBox is a combo box which displays the list of fields of a given layer. It might be combined with a QgsMapLayerComboBox to automatically update fields according to a chosen layer. If expression must be used, QgsFieldExpressionWidget shall be used instead.

See also

QgsMapLayerComboBox

Class Hierarchy¶

Base classes¶

QComboBox
QWidget
QObject
QPaintDevice

Methods

`allowEmptyFieldName`	Returns `True` if the combo box allows the empty field ("not set") choice.
`currentField`	Returns the currently selected field
`fields`	Returns the fields currently shown in the combobox.
`filters`	currently used filter on list of fields
`indexChanged`
`layer`	Returns the layer currently associated with the combobox.
`setAllowEmptyFieldName`	Sets whether an optional empty field ("not set") option is shown in the combo box.
`setField`	setField sets the currently selected field
`setFields`	Manually sets the fields to use for the combo box.
`setFilters`	setFilters allows filtering according to the type of field
`setLayer`	Sets the layer for which fields are listed in the combobox.

Signals

fieldChanged

Emitted when the currently selected field changes.

class qgis.gui.QgsFieldComboBox[source]¶

Bases: QComboBox

__init__(parent: QWidget | None = None)

QgsFieldComboBox creates a combo box to display the fields of a layer. The layer can be either manually given or dynamically set by connecting the signal QgsMapLayerComboBox.layerChanged to the slot setLayer.

Parameters:: parent (Optional[QWidget] = None)

allowEmptyFieldName(self) → bool[source]¶

Returns True if the combo box allows the empty field (“not set”) choice.

See also

setAllowEmptyFieldName()

Return type:: bool

currentField(self) → str[source]¶

Returns the currently selected field

Return type:: str

signal fieldChanged(fieldName: str)[source]¶

Emitted when the currently selected field changes.

Parameters:: fieldName (str)

fields(self) → QgsFields[source]¶

Returns the fields currently shown in the combobox.

This will either be fields from the associated layer() or the fields manually set by a call to setFields().

Added in version 3.14.

Return type:: QgsFields

filters(self) → QgsFieldProxyModel.Filters[source]¶

currently used filter on list of fields

Return type:: QgsFieldProxyModel.Filters

indexChanged(self, i: int)[source]¶

Parameters:: i (int)

layer(self) → QgsVectorLayer | None[source]¶

Returns the layer currently associated with the combobox.

See also

setLayer()

Return type:: Optional[QgsVectorLayer]

setAllowEmptyFieldName(self, allowEmpty: bool)[source]¶

Sets whether an optional empty field (“not set”) option is shown in the combo box.

See also

allowEmptyFieldName()

Parameters:: allowEmpty (bool)

setField(self, fieldName: str | None)[source]¶

setField sets the currently selected field

Parameters:: fieldName (Optional[str])

setFields(self, fields: QgsFields)[source]¶

Manually sets the fields to use for the combo box.

This method should only be used when the combo box ISN’T associated with a layer() and needs to show the fields from an arbitrary field collection instead. Calling setFields() will automatically clear any existing layer().

See also

fields()

Added in version 3.14.