Class: QgsFeaturePickerModelBase

Provides a list of features based on filter conditions.

Features are fetched asynchronously.

Added in version 3.14.

Note

This is an abstract class, with methods which must be implemented by a subclass.

The following methods must be implemented: requestToReloadCurrentFeature(), setExtraIdentifierValueToNull()

Class Hierarchy

Base classes

QAbstractItemModel
QObject

Subclasses

QgsFeatureFilterModel	Provides a list of features based on filter conditions.
QgsFeaturePickerModel	Provides a list of features based on filter conditions.

Enums

CustomRole	Extra roles that can be used to fetch data from this model.
Role	alias of CustomRole

Abstract Methods

setExtraIdentifierValueToNull

Allows specifying one value that does not need to match the filter criteria but will still be available in the model as NULL value(s).

Methods

allowNull	Add a NULL entry to the list.
displayExpression	The display expression will be used for
extraIdentifierValueIndex	The index at which the extra identifier value is available within the model.
extraValueDoesNotExist	Flag indicating that the extraIdentifierValue does not exist in the data.
fetchGeometry	Returns if the geometry is fetched
fetchLimit	Returns the feature request fetch limit
filterExpression	An additional filter expression to apply, next to the filterValue.
filterValue	This value will be used to filter the features available from this model.
formFeature	Returns an attribute form feature to be used with the filter expression.
isLoading	Indicator if the model is currently performing any feature iteration in the background.
parentFormFeature	Returns a parent attribute form feature to be used with the filter expression.
setAllowNull	Add a NULL entry to the list.
setDisplayExpression	The display expression will be used for
setFetchGeometry	Defines if the geometry will be fetched
setFetchLimit	Defines the feature request fetch limit If set to 0, no limit is applied when fetching
setFilterExpression	An additional filter expression to apply, next to the filterValue.
setFilterValue	This value will be used to filter the features available from this model.
setFormFeature	Sets an attribute form feature to be used with the filter expression.
setParentFormFeature	Sets a parent attribute form feature to be used with the filter expression.
setSourceLayer	The source layer from which features will be fetched.
sourceLayer	The source layer from which features will be fetched.

Signals

allowNullChanged	Add a NULL entry to the list.
beginUpdate	Notification that the model is about to be changed because a job was completed.
currentFeatureChanged	Emitted when the current feature in the model has changed This emitted both when the extra value changes and when the extra value status changes.
displayExpressionChanged	The display expression will be used for
endUpdate	Notification that the model change is finished.
extraIdentifierValueChanged	Allows specifying one value that does not need to match the filter criteria but will still be available in the model.
extraIdentifierValueIndexChanged	The index at which the extra identifier value is available within the model.
extraValueDoesNotExistChanged	Notification whether the model has found a feature tied to the extraIdentifierValue or not.
fetchGeometryChanged	Emitted when the fetching of the geometry changes
fetchLimitChanged	Emitted when the fetching limit for the feature request changes
filterExpressionChanged	An additional filter expression to apply, next to the filterValue.
filterJobCompleted	Indicates that a filter job has been completed and new data may be available.
filterValueChanged	This value will be used to filter the features available from this model.
formFeatureChanged	An attribute form feature to be used alongside the filter expression.
isLoadingChanged	Indicator if the model is currently performing any feature iteration in the background.
parentFormFeatureChanged	A parent attribute form feature to be used alongside the filter expression.
sourceLayerChanged	The source layer from which features will be fetched.

class qgis.core.QgsFeaturePickerModelBase

Bases: QAbstractItemModel

__init__(parent: QObject | None = None)

Create a new QgsFeaturePickerModelBase, optionally specifying a parent.

Parameters:

parent (Optional[QObject] = None)

class CustomRole(*values)

Bases: IntEnum

Extra roles that can be used to fetch data from this model.

Note

Prior to QGIS 3.36 this was available as QgsFeaturePickerModelBase.Role

Added in version 3.36.

• IdentifierValue: Used to retrieve the identifier value (primary key) of a feature.

  Deprecated since version 3.40.: Use IdentifierValuesRole instead.

  Available as QgsFeaturePickerModelBase.IdentifierValueRole in older QGIS releases.

• IdentifierValues: Used to retrieve the identifierValues (primary keys) of a feature.

  Available as QgsFeaturePickerModelBase.IdentifierValuesRole in older QGIS releases.

• Value: Used to retrieve the displayExpression of a feature.

  Available as QgsFeaturePickerModelBase.ValueRole in older QGIS releases.

• Feature: Used to retrieve the feature, it might be incomplete if the request doesn’t fetch all attributes or geometry.

  Available as QgsFeaturePickerModelBase.FeatureRole in older QGIS releases.

• FeatureId: Used to retrieve the id of a feature.

  Available as QgsFeaturePickerModelBase.FeatureIdRole in older QGIS releases.

Role

alias of CustomRole

allowNull(self) → bool

Add a NULL entry to the list.

Return type:

bool

signal allowNullChanged

Add a NULL entry to the list.

signal beginUpdate

Notification that the model is about to be changed because a job was completed.

signal currentFeatureChanged

Emitted when the current feature in the model has changed This emitted both when the extra value changes and when the extra value status changes. It allows being notified when the feature is fetched after the extra value has been set.

Added in version 3.16.5.

displayExpression(self) → str

The display expression will be used for

• displaying values in the combobox

• filtering based on filterValue

Return type:

str

signal displayExpressionChanged

The display expression will be used for

• displaying values in the combobox

• filtering based on filterValue

signal endUpdate

Notification that the model change is finished. Will always be emitted in sync with beginUpdate.

signal extraIdentifierValueChanged

Allows specifying one value that does not need to match the filter criteria but will still be available in the model.

extraIdentifierValueIndex(self) → int

The index at which the extra identifier value is available within the model.

Return type:

int

signal extraIdentifierValueIndexChanged(index: int)

The index at which the extra identifier value is available within the model.

Parameters:

index (int)

extraValueDoesNotExist(self) → bool

Flag indicating that the extraIdentifierValue does not exist in the data.

Return type:

bool

signal extraValueDoesNotExistChanged(found: bool)

Notification whether the model has found a feature tied to the extraIdentifierValue or not.

Parameters:

found (bool)

fetchGeometry(self) → bool

Returns if the geometry is fetched

Return type:

bool

signal fetchGeometryChanged

Emitted when the fetching of the geometry changes

fetchLimit(self) → int

Returns the feature request fetch limit

Return type:

int

signal fetchLimitChanged

Emitted when the fetching limit for the feature request changes

filterExpression(self) → str

An additional filter expression to apply, next to the filterValue. Can be used for spatial filtering etc.

Return type:

str

signal filterExpressionChanged

An additional filter expression to apply, next to the filterValue. Can be used for spatial filtering etc.

signal filterJobCompleted

Indicates that a filter job has been completed and new data may be available.

filterValue(self) → str

This value will be used to filter the features available from this model. Whenever a substring of the displayExpression of a feature matches the filter value, it will be accessible by this model.

Return type:

str

signal filterValueChanged

This value will be used to filter the features available from this model. Whenever a substring of the displayExpression of a feature matches the filter value, it will be accessible by this model.

formFeature(self) → QgsFeature

Returns an attribute form feature to be used with the filter expression.

Added in version 3.42.2.

Return type:

QgsFeature

signal formFeatureChanged

An attribute form feature to be used alongside the filter expression.

Added in version 3.42.2.

isLoading(self) → bool

Indicator if the model is currently performing any feature iteration in the background.

Return type:

bool

signal isLoadingChanged

Indicator if the model is currently performing any feature iteration in the background.

parentFormFeature(self) → QgsFeature

Returns a parent attribute form feature to be used with the filter expression.

Added in version 3.42.2.

Return type:

QgsFeature

signal parentFormFeatureChanged

A parent attribute form feature to be used alongside the filter expression.

Added in version 3.42.2.

setAllowNull(self, allowNull: bool)

Add a NULL entry to the list.

Parameters:

allowNull (bool)

setDisplayExpression(self, displayExpression: str | None)

The display expression will be used for

• displaying values in the combobox

• filtering based on filterValue

Parameters:

displayExpression (Optional[str])

abstract setExtraIdentifierValueToNull(self)

Allows specifying one value that does not need to match the filter criteria but will still be available in the model as NULL value(s).

setFetchGeometry(self, fetchGeometry: bool)

Defines if the geometry will be fetched

Parameters:

fetchGeometry (bool)

setFetchLimit(self, fetchLimit: int)

Defines the feature request fetch limit If set to 0, no limit is applied when fetching

Parameters:

fetchLimit (int)

setFilterExpression(self, filterExpression: str | None)

An additional filter expression to apply, next to the filterValue. Can be used for spatial filtering etc.

Parameters:

filterExpression (Optional[str])

setFilterValue(self, filterValue: str | None)

This value will be used to filter the features available from this model. Whenever a substring of the displayExpression of a feature matches the filter value, it will be accessible by this model.

Parameters:

filterValue (Optional[str])

setFormFeature(self, feature: QgsFeature)

Sets an attribute form feature to be used with the filter expression.

Added in version 3.42.2.

Parameters:

feature (QgsFeature)

setParentFormFeature(self, feature: QgsFeature)

Sets a parent attribute form feature to be used with the filter expression.

Added in version 3.42.2.

Parameters:

feature (QgsFeature)

setSourceLayer(self, sourceLayer: QgsVectorLayer | None)

The source layer from which features will be fetched.

Parameters:

sourceLayer (Optional[QgsVectorLayer])

sourceLayer(self) → QgsVectorLayer | None

The source layer from which features will be fetched.

Return type:

Optional[QgsVectorLayer]

signal sourceLayerChanged

The source layer from which features will be fetched.