Class: QgsVectorLayerEditBuffer

Stores queued vector layer edit operations prior to committing changes to the layer’s data provider.

Class Hierarchy

Base classes

QObject

Subclasses

QgsVectorLayerEditPassthrough

An edit buffer which directly passes commands through, used when a layer is within a transaction.

Methods

addedAttributes	Returns a list of added attributes fields which are not committed.
addedFeatures	Returns a map of new features which are not committed.
allAddedOrEditedFeatures	Returns a list of the features IDs for all newly added or edited features in the buffer.
changedAttributeValues	Returns a map of features with changed attributes values which are not committed.
changedGeometries	Returns a map of features with changed geometries which are not committed.
deletedAttributeIds	Returns a list of deleted attributes fields which are not committed.
deletedFeatureIds	Returns a list of deleted feature IDs which are not committed.
editBufferGroup	Returns the parent edit buffer group for this edit buffer, or None if not part of a group.
handleAttributeAdded	Update added and changed features after addition of an attribute
handleAttributeDeleted	Update added and changed features after removal of an attribute
isAttributeDeleted	Returns True if the specified attribute has been deleted but not committed.
isFeatureAdded	Returns True if the specified feature ID has been added but not committed.
isFeatureAttributesChanged	Returns True if the specified feature ID has had an attribute changed but not committed.
isFeatureDeleted	Returns True if the specified feature ID has been deleted but not committed.
isFeatureGeometryChanged	Returns True if the specified feature ID has had its geometry changed but not committed.
setEditBufferGroup	Set the parent edit buffer group for this edit buffer.
undoIndexChanged
updateAttributeMapIndex	Updates an index in an attribute map to a new value (for updates of changed attributes)
updateChangedAttributes	Update feature with uncommitted attribute updates
updateFeatureGeometry	Update feature with uncommitted geometry updates
updateLayerFields

Virtual Methods

In PyQGIS, only methods marked as virtual can be safely overridden in a Python subclass of QgsVectorLayerEditBuffer. See the FAQ for more details.

addAttribute	Adds an attribute field (but does not commit it) returns True if the field was added
addFeature	Adds a feature
addFeatures	Insert a copy of the given features into the layer (but does not commit it)
changeAttributeValue	Changed an attribute value (but does not commit it)
changeAttributeValues	Changes values of attributes (but does not commit it).
changeGeometry	Change feature's geometry
commitChanges	Attempts to commit any changes to disk.
deleteAttribute	Deletes an attribute field (but does not commit it)
deleteFeature	Delete a feature from the layer (but does not commit it)
deleteFeatures	Deletes a set of features from the layer (but does not commit it)
isModified	Returns True if the provider has been modified since the last commit
renameAttribute	Renames an attribute field (but does not commit it)
rollBack	Stop editing and discard the edits

Signals

attributeAdded	Emitted when an attribute was added to the buffer.
attributeDeleted	Emitted when an attribute was deleted from the buffer.
attributeRenamed	Emitted when an attribute has been renamed
attributeValueChanged	Emitted when a feature's attribute value has been changed.
committedAttributeValuesChanges	Emitted after feature attribute value changes have been committed to the layer.
committedAttributesAdded	Emitted after attribute addition has been committed to the layer.
committedAttributesDeleted	Emitted after attribute deletion has been committed to the layer.
committedAttributesRenamed	Emitted after committing an attribute rename
committedFeaturesAdded	Emitted after feature addition has been committed to the layer.
committedFeaturesRemoved	Emitted after feature removal has been committed to the layer.
committedGeometriesChanges	Emitted after feature geometry changes have been committed to the layer.
featureAdded	Emitted when a feature has been added to the buffer
featureDeleted	Emitted when a feature was deleted from the buffer
geometryChanged	Emitted when a feature's geometry is changed.
layerModified	Emitted when modifications has been done on layer

class qgis.core.QgsVectorLayerEditBuffer

Bases: QObject

virtual addAttribute(self, field: QgsField) → bool

Adds an attribute field (but does not commit it) returns True if the field was added

Parameters:

field (QgsField)

Return type:

bool

virtual addFeature(self, f: QgsFeature) → bool

Adds a feature

Parameters:

f (QgsFeature) – feature to add

Return type:

bool

Returns:

True in case of success and False in case of error

virtual addFeatures(self, features: Iterable[QgsFeature]) → bool

Insert a copy of the given features into the layer (but does not commit it)

Parameters:

features (Iterable[QgsFeature])

Return type:

bool

addedAttributes(self) → Any

Returns a list of added attributes fields which are not committed.

Return type:

Any

addedFeatures(self) → Any

Returns a map of new features which are not committed.

See also

isFeatureAdded()

Return type:

Any

allAddedOrEditedFeatures(self) → Any

Returns a list of the features IDs for all newly added or edited features in the buffer.

Added in version 3.20.

Return type:

Any

signal attributeAdded(idx: int)

Emitted when an attribute was added to the buffer.

Parameters:

idx (int)

signal attributeDeleted(idx: int)

Emitted when an attribute was deleted from the buffer.

Parameters:

idx (int)

signal attributeRenamed(idx: int, newName: str)

Emitted when an attribute has been renamed

Parameters:

• idx (int) – attribute index

• newName (str) – new attribute name

signal attributeValueChanged(fid: QgsFeatureId, idx: int, value: object)

Emitted when a feature’s attribute value has been changed.

Parameters:

• fid (QgsFeatureId)

• idx (int)

• value (object)

virtual changeAttributeValue(self, fid: int, field: int, newValue: Any, oldValue: Any = None) → bool

Changed an attribute value (but does not commit it)

Parameters:

• fid (int)

• field (int)

• newValue (Any)

• oldValue (Any = None)

Return type:

bool

virtual changeAttributeValues(self, fid: int, newValues: Dict[int, Any], oldValues: Dict[int, Any]) → bool

Changes values of attributes (but does not commit it).

Return type:

bool

Returns:

True if attributes are well updated, False otherwise

Parameters:

• fid (int)

• newValues (Dict[int, Any])

• oldValues (Dict[int, Any])

virtual changeGeometry(self, fid: int, geom: QgsGeometry) → bool

Change feature’s geometry

Parameters:

• fid (int)

• geom (QgsGeometry)

Return type:

bool

changedAttributeValues(self) → Any

Returns a map of features with changed attributes values which are not committed.

See also

isFeatureAttributesChanged()

Return type:

Any

changedGeometries(self) → Any

Returns a map of features with changed geometries which are not committed.

See also

isFeatureGeometryChanged()

Return type:

Any

virtual commitChanges(self, commitErrors: Iterable[str | None]) → bool

Attempts to commit any changes to disk. Returns the result of the attempt. If a commit fails, the in-memory changes are left alone.

This allows editing to continue if the commit failed on e.g. a disallowed value in a Postgres database - the user can re-edit and try again.

The commits occur in distinct stages, (add attributes, add features, change attribute values, change geometries, delete features, delete attributes) so if a stage fails, it’s difficult to roll back cleanly. Therefore any error message also includes which stage failed so that the user has some chance of repairing the damage cleanly.

Parameters:

commitErrors (Iterable[Optional[str]])

Return type:

bool

signal committedAttributeValuesChanges(layerId: str, changedAttributesValues: QgsChangedAttributesMap)

Emitted after feature attribute value changes have been committed to the layer.

Parameters:

• layerId (str)

• changedAttributesValues (QgsChangedAttributesMap)

signal committedAttributesAdded(layerId: str, addedAttributes: List[QgsField])

Emitted after attribute addition has been committed to the layer.

Parameters:

• layerId (str)

• addedAttributes (List[QgsField])

signal committedAttributesDeleted(layerId: str, deletedAttributes: QgsAttributeList)

Emitted after attribute deletion has been committed to the layer.

Parameters:

• layerId (str)

• deletedAttributes (QgsAttributeList)

signal committedAttributesRenamed(layerId: str, renamedAttributes: QgsFieldNameMap)

Emitted after committing an attribute rename

Parameters:

• layerId (str) – ID of layer

• renamedAttributes (QgsFieldNameMap) – map of field index to new name

signal committedFeaturesAdded(layerId: str, addedFeatures: QgsFeatureList)

Emitted after feature addition has been committed to the layer.

Parameters:

• layerId (str)

• addedFeatures (QgsFeatureList)

signal committedFeaturesRemoved(layerId: str, deletedFeatureIds: QgsFeatureIds)

Emitted after feature removal has been committed to the layer.

Parameters:

• layerId (str)

• deletedFeatureIds (QgsFeatureIds)

signal committedGeometriesChanges(layerId: str, changedGeometries: QgsGeometryMap)

Emitted after feature geometry changes have been committed to the layer.

Parameters:

• layerId (str)

• changedGeometries (QgsGeometryMap)

virtual deleteAttribute(self, attr: int) → bool

Deletes an attribute field (but does not commit it)

Parameters:

attr (int)

Return type:

bool

virtual deleteFeature(self, fid: int) → bool

Delete a feature from the layer (but does not commit it)

Parameters:

fid (int)

Return type:

bool

virtual deleteFeatures(self, fid: Any) → bool

Deletes a set of features from the layer (but does not commit it)

Parameters:

fid (Any)

Return type:

bool

deletedAttributeIds(self) → List[int]

Returns a list of deleted attributes fields which are not committed. The list is kept sorted.

See also

isAttributeDeleted()

Return type:

List[int]

deletedFeatureIds(self) → Any

Returns a list of deleted feature IDs which are not committed.

See also

isFeatureDeleted()

Return type:

Any

editBufferGroup(self) → QgsVectorLayerEditBufferGroup | None

Returns the parent edit buffer group for this edit buffer, or None if not part of a group.

Added in version 3.26.

Return type:

Optional[QgsVectorLayerEditBufferGroup]

signal featureAdded(fid: QgsFeatureId)

Emitted when a feature has been added to the buffer

Parameters:

fid (QgsFeatureId)

signal featureDeleted(fid: QgsFeatureId)

Emitted when a feature was deleted from the buffer

Parameters:

fid (QgsFeatureId)

signal geometryChanged(fid: QgsFeatureId, geom: QgsGeometry)

Emitted when a feature’s geometry is changed.

Parameters:

• fid (QgsFeatureId) – feature ID

• geom (QgsGeometry) – new feature geometry

handleAttributeAdded(self, index: int, field: QgsField)

Update added and changed features after addition of an attribute

Parameters:

• index (int)

• field (QgsField)

handleAttributeDeleted(self, index: int)

Update added and changed features after removal of an attribute

Parameters:

index (int)

isAttributeDeleted(self, index: int) → bool

Returns True if the specified attribute has been deleted but not committed.

Parameters:

index (int) – attribute index

See also

deletedAttributeIds()

Return type:

bool

isFeatureAdded(self, id: int) → bool

Returns True if the specified feature ID has been added but not committed.

Parameters:

id (int) – feature ID

See also

addedFeatures()

Return type:

bool

isFeatureAttributesChanged(self, id: int) → bool

Returns True if the specified feature ID has had an attribute changed but not committed.

Parameters:

id (int) – feature ID

See also

changedAttributeValues()

Return type:

bool

isFeatureDeleted(self, id: int) → bool

Returns True if the specified feature ID has been deleted but not committed.

Parameters:

id (int) – feature ID

See also

deletedFeatureIds()

Return type:

bool

isFeatureGeometryChanged(self, id: int) → bool

Returns True if the specified feature ID has had its geometry changed but not committed.

Parameters:

id (int) – feature ID

See also

changedGeometries()

Return type:

bool

virtual isModified(self) → bool

Returns True if the provider has been modified since the last commit

Return type:

bool

signal layerModified

Emitted when modifications has been done on layer

virtual renameAttribute(self, attr: int, newName: str | None) → bool

Renames an attribute field (but does not commit it)

Parameters:

• attr (int) – attribute index

• newName (Optional[str]) – new name of field

Return type:

bool

virtual rollBack(self)

Stop editing and discard the edits

setEditBufferGroup(self, editBufferGroup: QgsVectorLayerEditBufferGroup | None)

Set the parent edit buffer group for this edit buffer.

Added in version 3.26.

Parameters:

editBufferGroup (Optional[QgsVectorLayerEditBufferGroup])

undoIndexChanged(self, index: int)

Parameters:

index (int)

updateAttributeMapIndex(self, attrs: Dict[int, Any], index: int, offset: int)

Updates an index in an attribute map to a new value (for updates of changed attributes)

Parameters:

• attrs (Dict[int, Any])

• index (int)

• offset (int)

updateChangedAttributes(self, f: QgsFeature)

Update feature with uncommitted attribute updates

Parameters:

f (QgsFeature)

updateFeatureGeometry(self, f: QgsFeature)

Update feature with uncommitted geometry updates

Parameters:

f (QgsFeature)

updateLayerFields(self)