Class: QgsVectorLayerFeatureIterator

class qgis.core.QgsVectorLayerFeatureIterator(source: QgsVectorLayerFeatureSource, ownSource: bool, request: QgsFeatureRequest)

Bases: QgsAbstractFeatureIteratorFromSourceQgsVectorLayerFeatureSourceBase

Methods

close

end of iterating: free the resources / lock

deref

Remove reference, delete if refs == 0

fetchFeature

fetch next feature, return True on success

filterRectToSourceCrs

Returns a rectangle representing the original request’s QgsFeatureRequest.filterRect().

geometryToDestinationCrs

Transforms feature’s geometry according to the specified coordinate transform.

isValid

rtype

bool

iteratorClosed

to be called by from subclass in close()

nextFeatureFilterExpression

Overrides default method as we only need to filter features in the edit buffer while for others filtering is left to the provider implementation.

nextFeatureFilterFids

By default, the iterator will fetch all features and check if the id is in the request.

prepareSimplification

Setup the simplification of geometries to fetch using the specified simplify method

ref

Add reference

rewind

reset the iterator to the starting position

class FetchJoinInfo
class FetchJoinInfo(QgsVectorLayerFeatureIterator.FetchJoinInfo)None

Bases: sip.wrapper

addJoinedAttributesCached(self, f: QgsFeature, joinValue: Any)
Parameters
addJoinedAttributesDirect(self, f: QgsFeature, joinValue: Any)
Parameters
attributes
indexOffset
joinField
joinInfo
targetField
close(self)bool

end of iterating: free the resources / lock

Return type

bool

deref(self)

Remove reference, delete if refs == 0

fetchFeature(self, feature: QgsFeature)bool

fetch next feature, return True on success

Parameters

feature (QgsFeature) –

Return type

bool

filterRectToSourceCrs(self, transform: QgsCoordinateTransform)QgsRectangle

Returns a rectangle representing the original request’s QgsFeatureRequest.filterRect(). If transform is a valid coordinate transform, the return rectangle will represent the requested filterRect() transformed to the source’s coordinate reference system. Iterators should call this method and use the returned rectangle for filtering features to ensure that any QgsFeatureRequest.destinationCrs() set on the request is respected. Will throw a QgsCsException if the rect cannot be transformed from the destination CRS.

New in version 3.0.

geometryToDestinationCrs(self, feature: QgsFeature, transform: QgsCoordinateTransform)

Transforms feature’s geometry according to the specified coordinate transform. If feature has no geometry or transform is invalid then calling this method has no effect and will be shortcut. Iterators should call this method before returning features to ensure that any QgsFeatureRequest.destinationCrs() set on the request is respected.

New in version 3.0.

isValid(self)bool
Return type

bool

iteratorClosed(self)

to be called by from subclass in close()

nextFeatureFilterExpression(self, f: QgsFeature)bool

Overrides default method as we only need to filter features in the edit buffer while for others filtering is left to the provider implementation.

Parameters

f (QgsFeature) –

Return type

bool

nextFeatureFilterFids(self, f: QgsFeature)bool

By default, the iterator will fetch all features and check if the id is in the request. If you have a more sophisticated metodology (SQL request for the features…) and you are sure, that any feature you return from fetchFeature will match if the request was FilterFids you can just redirect this call to fetchFeature so the default check will be omitted.

Parameters

f – The feature to write to

Returns

True if a feature was written to f

prepareSimplification(self, simplifyMethod: QgsSimplifyMethod)bool

Setup the simplification of geometries to fetch using the specified simplify method

Parameters

simplifyMethod (QgsSimplifyMethod) –

Return type

bool

ref(self)

Add reference

rewind(self)bool

reset the iterator to the starting position

Return type

bool