A feature iterator which iterates over features from a QgsVectorLayer. More...

#include <qgsvectorlayerfeatureiterator.h>

Inheritance diagram for QgsVectorLayerFeatureIterator:

[legend]

Classes
struct	FetchJoinInfo
	Join information prepared for fast attribute id mapping in QgsVectorLayerJoinBuffer::updateFeatureAttributes(). More...

Public Member Functions
	QgsVectorLayerFeatureIterator (QgsVectorLayerFeatureSource *source, bool ownSource, const QgsFeatureRequest &request)
	~QgsVectorLayerFeatureIterator () override
bool	close () override
	end of iterating: free the resources / lock
bool	isValid () const override
	Returns if this iterator is valid.
bool	rewind () override
	reset the iterator to the starting position
void	setInterruptionChecker (QgsFeedback *interruptionChecker) override
	Attach an object that can be queried regularly by the iterator to check if it must stopped.
Public Member Functions inherited from QgsAbstractFeatureIteratorFromSource< QgsVectorLayerFeatureSource >
	QgsAbstractFeatureIteratorFromSource (QgsVectorLayerFeatureSource *source, bool ownSource, const QgsFeatureRequest &request)
	~QgsAbstractFeatureIteratorFromSource () override
Public Member Functions inherited from QgsAbstractFeatureIterator
	QgsAbstractFeatureIterator (const QgsFeatureRequest &request)
	base class constructor - stores the iteration parameters
virtual	~QgsAbstractFeatureIterator ()=default
	destructor makes sure that the iterator is closed properly
bool	compileFailed () const
	Indicator if there was an error when sending the compiled query to the server.
CompileStatus	compileStatus () const
	Returns the status of expression compilation for filter expression requests.
virtual bool	nextFeature (QgsFeature &f)
	Fetch next feature and stores in f, returns `true` on success.

Protected Member Functions
void	addExpressionAttribute (QgsFeature &f, int attrIndex)
	Adds an expression based attribute to a feature.
void	addJoinedAttributes (QgsFeature &f)
void	addVirtualAttributes (QgsFeature &f)
	Adds attributes that don't source from the provider but are added inside QGIS Includes.
bool	fetchFeature (QgsFeature &feature) override
	fetch next feature, return `true` on success
bool	fetchNextAddedFeature (QgsFeature &f)
bool	fetchNextChangedAttributeFeature (QgsFeature &f)
bool	fetchNextChangedGeomFeature (QgsFeature &f)
bool	nextFeatureFid (QgsFeature &f)
bool	nextFeatureFilterExpression (QgsFeature &f) override
	Overrides default method as we only need to filter features in the edit buffer while for others filtering is left to the provider implementation.
void	prepareExpression (int fieldIdx)
void	prepareField (int fieldIdx)
void	prepareFields ()
void	prepareJoin (int fieldIdx)
bool	prepareSimplification (const QgsSimplifyMethod &simplifyMethod) override
	Setup the simplification of geometries to fetch using the specified simplify method.
void	rewindEditBuffer ()
void	updateChangedAttributes (QgsFeature &f)
	Update feature with uncommitted attribute updates.
void	updateFeatureGeometry (QgsFeature &f)
	Update feature with uncommitted geometry updates.
void	useAddedFeature (const QgsFeature &src, QgsFeature &f)
void	useChangedAttributeFeature (QgsFeatureId fid, const QgsGeometry &geom, QgsFeature &f)
Protected Member Functions inherited from QgsAbstractFeatureIteratorFromSource< QgsVectorLayerFeatureSource >
void	iteratorClosed ()
	to be called by from subclass in close()
Protected Member Functions inherited from QgsAbstractFeatureIterator
void	deref ()
	Remove reference, delete if refs == 0.
QgsRectangle	filterRectToSourceCrs (const QgsCoordinateTransform &transform) const
	Returns a rectangle representing the original request's QgsFeatureRequest::filterRect().
void	geometryToDestinationCrs (QgsFeature &feature, const QgsCoordinateTransform &transform) const
	Transforms feature's geometry according to the specified coordinate transform.
virtual bool	nextFeatureFilterFids (QgsFeature &f)
	By default, the iterator will fetch all features and check if the id is in the request.
void	ref ()
	Add reference.
RequestToSourceCrsResult	updateRequestToSourceCrs (QgsFeatureRequest &request, const QgsCoordinateTransform &transform) const
	Update a QgsFeatureRequest so that spatial filters are transformed to the source's coordinate reference system.

Protected Attributes
QgsFeatureIterator	mChangedFeaturesIterator
QgsFeatureRequest	mChangedFeaturesRequest
double	mDistanceWithin = 0
std::shared_ptr< QgsGeometryEngine >	mDistanceWithinEngine
QgsGeometry	mDistanceWithinGeom
QMap< int, QgsExpression * >	mExpressionFieldInfo
QgsFeatureMap::ConstIterator	mFetchAddedFeaturesIt
QgsGeometryMap::ConstIterator	mFetchChangedGeomIt
QSet< QgsFeatureId >	mFetchConsidered
bool	mFetchedFid = false
QMap< const QgsVectorLayerJoinInfo *, QgsVectorLayerFeatureIterator::FetchJoinInfo >	mFetchJoinInfo
	Information about joins used in the current select() statement.
QgsRectangle	mFilterRect
bool	mHasValidTransform = false
bool	mHasVirtualAttributes
QgsFeatureIterator	mProviderIterator
QgsFeatureRequest	mProviderRequest
QgsCoordinateTransform	mTransform
Protected Attributes inherited from QgsAbstractFeatureIteratorFromSource< QgsVectorLayerFeatureSource >
bool	mOwnSource
QgsVectorLayerFeatureSource *	mSource
Protected Attributes inherited from QgsAbstractFeatureIterator
bool	mClosed = false
	Sets to `true`, as soon as the iterator is closed.
bool	mCompileFailed = false
CompileStatus	mCompileStatus = NoCompilation
	Status of compilation of filter expression.
long long	mFetchedCount = 0
	Number of features already fetched by iterator.
QgsFeatureRequest	mRequest
	A copy of the feature request.
bool	mValid = true
	An invalid state of a feature iterator indicates that there was a problem with even getting it up and running.
bool	mZombie = false
	A feature iterator may be closed already but still be serving features from the cache.
int	refs = 0
	reference counting (to allow seamless copying of QgsFeatureIterator instances)

Additional Inherited Members
Public Types inherited from QgsAbstractFeatureIterator
enum	CompileStatus { NoCompilation , PartiallyCompiled , Compiled }
	Status of expression compilation for filter expression requests. More...
enum class	RequestToSourceCrsResult : int { Success , DistanceWithinMustBeCheckedManually }
	Possible results from the updateRequestToSourceCrs() method. More...

Detailed Description

A feature iterator which iterates over features from a QgsVectorLayer.

Definition at line 161 of file qgsvectorlayerfeatureiterator.h.

Constructor & Destructor Documentation

◆ QgsVectorLayerFeatureIterator()

QgsVectorLayerFeatureIterator::QgsVectorLayerFeatureIterator	(	QgsVectorLayerFeatureSource *	source,
		bool	ownSource,
		const QgsFeatureRequest &	request )

Definition at line 155 of file qgsvectorlayerfeatureiterator.cpp.

◆ ~QgsVectorLayerFeatureIterator()

QgsVectorLayerFeatureIterator::~QgsVectorLayerFeatureIterator ( )

override

Definition at line 385 of file qgsvectorlayerfeatureiterator.cpp.

Member Function Documentation

◆ addExpressionAttribute()

void QgsVectorLayerFeatureIterator::addExpressionAttribute	(	QgsFeature &	f,
		int	attrIndex )

protected

Adds an expression based attribute to a feature.

Parameters

f	feature
attrIndex	attribute index

Note: not available in Python bindings

Definition at line 1135 of file qgsvectorlayerfeatureiterator.cpp.

◆ addJoinedAttributes()

void QgsVectorLayerFeatureIterator::addJoinedAttributes ( QgsFeature & f )

protected

Note: not available in Python bindings

Definition at line 1073 of file qgsvectorlayerfeatureiterator.cpp.

◆ addVirtualAttributes()

void QgsVectorLayerFeatureIterator::addVirtualAttributes ( QgsFeature & f )

protected

Adds attributes that don't source from the provider but are added inside QGIS Includes.

Joined fields
Expression fields

Parameters

f	The feature will be modified

Note: not available in Python bindings

Definition at line 1095 of file qgsvectorlayerfeatureiterator.cpp.

◆ close()

bool QgsVectorLayerFeatureIterator::close ( )

overridevirtual

end of iterating: free the resources / lock

Implements QgsAbstractFeatureIterator.

Definition at line 617 of file qgsvectorlayerfeatureiterator.cpp.

◆ fetchFeature()

bool QgsVectorLayerFeatureIterator::fetchFeature ( QgsFeature & feature )

overrideprotectedvirtual

fetch next feature, return true on success

Implements QgsAbstractFeatureIterator.

Definition at line 482 of file qgsvectorlayerfeatureiterator.cpp.

◆ fetchNextAddedFeature()

bool QgsVectorLayerFeatureIterator::fetchNextAddedFeature ( QgsFeature & f )

protected

Note: not available in Python bindings

Definition at line 641 of file qgsvectorlayerfeatureiterator.cpp.

◆ fetchNextChangedAttributeFeature()

bool QgsVectorLayerFeatureIterator::fetchNextChangedAttributeFeature ( QgsFeature & f )

protected

Note: not available in Python bindings

Definition at line 726 of file qgsvectorlayerfeatureiterator.cpp.

◆ fetchNextChangedGeomFeature()

bool QgsVectorLayerFeatureIterator::fetchNextChangedGeomFeature ( QgsFeature & f )

protected

Note: not available in Python bindings

Definition at line 687 of file qgsvectorlayerfeatureiterator.cpp.

◆ isValid()

bool QgsVectorLayerFeatureIterator::isValid ( ) const

overridevirtual

Returns if this iterator is valid.

An invalid feature iterator is not able to provide a reliable source for data. If an iterator is invalid, either give up or try to send the request again (preferably after a timeout to give the system some time to stay responsive).

If you want to check if the iterator successfully completed, better use QgsFeatureIterator::isClosed().

Reimplemented from QgsAbstractFeatureIterator.

Definition at line 636 of file qgsvectorlayerfeatureiterator.cpp.

◆ nextFeatureFid()

bool QgsVectorLayerFeatureIterator::nextFeatureFid ( QgsFeature & f )

protected

Note: not available in Python bindings

Definition at line 1275 of file qgsvectorlayerfeatureiterator.cpp.

◆ nextFeatureFilterExpression()

bool QgsVectorLayerFeatureIterator::nextFeatureFilterExpression ( QgsFeature & f )

inlineoverrideprotectedvirtual

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

Reimplemented from QgsAbstractFeatureIterator.

Definition at line 230 of file qgsvectorlayerfeatureiterator.h.

◆ prepareExpression()

void QgsVectorLayerFeatureIterator::prepareExpression ( int fieldIdx )

protected

Note: not available in Python bindings

Definition at line 848 of file qgsvectorlayerfeatureiterator.cpp.

◆ prepareField()

void QgsVectorLayerFeatureIterator::prepareField ( int fieldIdx )

protected

Note: not available in Python bindings

Definition at line 1051 of file qgsvectorlayerfeatureiterator.cpp.

◆ prepareFields()

void QgsVectorLayerFeatureIterator::prepareFields ( )

protected

Note: not available in Python bindings

Definition at line 908 of file qgsvectorlayerfeatureiterator.cpp.

◆ prepareJoin()

void QgsVectorLayerFeatureIterator::prepareJoin ( int fieldIdx )

protected

Note: not available in Python bindings

Definition at line 806 of file qgsvectorlayerfeatureiterator.cpp.

◆ prepareSimplification()

bool QgsVectorLayerFeatureIterator::prepareSimplification ( const QgsSimplifyMethod & simplifyMethod )

overrideprotectedvirtual

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

Reimplemented from QgsAbstractFeatureIterator.

Definition at line 1154 of file qgsvectorlayerfeatureiterator.cpp.

◆ rewind()

bool QgsVectorLayerFeatureIterator::rewind ( )

overridevirtual

reset the iterator to the starting position

Implements QgsAbstractFeatureIterator.

Definition at line 599 of file qgsvectorlayerfeatureiterator.cpp.

◆ rewindEditBuffer()

void QgsVectorLayerFeatureIterator::rewindEditBuffer ( )

protected

Note: not available in Python bindings

Definition at line 798 of file qgsvectorlayerfeatureiterator.cpp.

◆ setInterruptionChecker()

void QgsVectorLayerFeatureIterator::setInterruptionChecker ( QgsFeedback * interruptionChecker )

overridevirtual

Attach an object that can be queried regularly by the iterator to check if it must stopped.

This is mostly useful for iterators where a single nextFeature()/fetchFeature() iteration might be very long. A typical use case is the WFS provider. When nextFeature()/fetchFeature() is reasonably fast, it is not necessary to implement this method. The default implementation does nothing.

Note: not available in Python bindings

Reimplemented from QgsAbstractFeatureIterator.

Definition at line 630 of file qgsvectorlayerfeatureiterator.cpp.

◆ updateChangedAttributes()

void QgsVectorLayerFeatureIterator::updateChangedAttributes ( QgsFeature & f )

protected

Update feature with uncommitted attribute updates.

Note: not available in Python bindings

Definition at line 1320 of file qgsvectorlayerfeatureiterator.cpp.

◆ updateFeatureGeometry()

void QgsVectorLayerFeatureIterator::updateFeatureGeometry ( QgsFeature & f )

protected

Update feature with uncommitted geometry updates.

Note: not available in Python bindings

Definition at line 1343 of file qgsvectorlayerfeatureiterator.cpp.

◆ useAddedFeature()

void QgsVectorLayerFeatureIterator::useAddedFeature	(	const QgsFeature &	src,
		QgsFeature &	f )

protected

Note: not available in Python bindings

Definition at line 671 of file qgsvectorlayerfeatureiterator.cpp.

◆ useChangedAttributeFeature()

void QgsVectorLayerFeatureIterator::useChangedAttributeFeature	(	QgsFeatureId	fid,
		const QgsGeometry &	geom,
		QgsFeature &	f )

protected

Note: not available in Python bindings

Definition at line 762 of file qgsvectorlayerfeatureiterator.cpp.

Member Data Documentation

◆ mChangedFeaturesIterator

QgsFeatureIterator QgsVectorLayerFeatureIterator::mChangedFeaturesIterator

protected

Definition at line 300 of file qgsvectorlayerfeatureiterator.h.

◆ mChangedFeaturesRequest

QgsFeatureRequest QgsVectorLayerFeatureIterator::mChangedFeaturesRequest

protected

Definition at line 299 of file qgsvectorlayerfeatureiterator.h.

◆ mDistanceWithin

double QgsVectorLayerFeatureIterator::mDistanceWithin = 0

protected

Definition at line 310 of file qgsvectorlayerfeatureiterator.h.

◆ mDistanceWithinEngine

std::shared_ptr< QgsGeometryEngine > QgsVectorLayerFeatureIterator::mDistanceWithinEngine

protected

Definition at line 309 of file qgsvectorlayerfeatureiterator.h.

◆ mDistanceWithinGeom

QgsGeometry QgsVectorLayerFeatureIterator::mDistanceWithinGeom

protected

Definition at line 308 of file qgsvectorlayerfeatureiterator.h.

◆ mExpressionFieldInfo

QMap<int, QgsExpression *> QgsVectorLayerFeatureIterator::mExpressionFieldInfo

protected

Definition at line 325 of file qgsvectorlayerfeatureiterator.h.

◆ mFetchAddedFeaturesIt

QgsFeatureMap::ConstIterator QgsVectorLayerFeatureIterator::mFetchAddedFeaturesIt

protected

Definition at line 315 of file qgsvectorlayerfeatureiterator.h.

◆ mFetchChangedGeomIt

QgsGeometryMap::ConstIterator QgsVectorLayerFeatureIterator::mFetchChangedGeomIt

protected

Definition at line 314 of file qgsvectorlayerfeatureiterator.h.

◆ mFetchConsidered

QSet<QgsFeatureId> QgsVectorLayerFeatureIterator::mFetchConsidered

protected

Definition at line 313 of file qgsvectorlayerfeatureiterator.h.

◆ mFetchedFid

bool QgsVectorLayerFeatureIterator::mFetchedFid = false

protected

Definition at line 317 of file qgsvectorlayerfeatureiterator.h.

◆ mFetchJoinInfo

QMap<const QgsVectorLayerJoinInfo *, QgsVectorLayerFeatureIterator::FetchJoinInfo> QgsVectorLayerFeatureIterator::mFetchJoinInfo

protected

Information about joins used in the current select() statement.

Allows faster mapping of attribute ids compared to mVectorJoins.

Definition at line 323 of file qgsvectorlayerfeatureiterator.h.

◆ mFilterRect

QgsRectangle QgsVectorLayerFeatureIterator::mFilterRect

protected

Definition at line 303 of file qgsvectorlayerfeatureiterator.h.

◆ mHasValidTransform

bool QgsVectorLayerFeatureIterator::mHasValidTransform = false

protected

Definition at line 304 of file qgsvectorlayerfeatureiterator.h.

◆ mHasVirtualAttributes

bool QgsVectorLayerFeatureIterator::mHasVirtualAttributes

protected

Definition at line 327 of file qgsvectorlayerfeatureiterator.h.

◆ mProviderIterator

QgsFeatureIterator QgsVectorLayerFeatureIterator::mProviderIterator

protected

Definition at line 298 of file qgsvectorlayerfeatureiterator.h.

◆ mProviderRequest

QgsFeatureRequest QgsVectorLayerFeatureIterator::mProviderRequest

protected

Definition at line 297 of file qgsvectorlayerfeatureiterator.h.

◆ mTransform

QgsCoordinateTransform QgsVectorLayerFeatureIterator::mTransform

protected

Definition at line 305 of file qgsvectorlayerfeatureiterator.h.

The documentation for this class was generated from the following files:

/build/qgis-4.3.0+git20261108+e0370aa57ef+99sid/src/core/vector/qgsvectorlayerfeatureiterator.h
/build/qgis-4.3.0+git20261108+e0370aa57ef+99sid/src/core/vector/qgsvectorlayerfeatureiterator.cpp

Classes

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ QgsVectorLayerFeatureIterator()

◆ ~QgsVectorLayerFeatureIterator()

Member Function Documentation

◆ addExpressionAttribute()

◆ addJoinedAttributes()

◆ addVirtualAttributes()

◆ close()

◆ fetchFeature()

◆ fetchNextAddedFeature()

◆ fetchNextChangedAttributeFeature()

◆ fetchNextChangedGeomFeature()

◆ isValid()

◆ nextFeatureFid()

◆ nextFeatureFilterExpression()

◆ prepareExpression()

◆ prepareField()

◆ prepareFields()

◆ prepareJoin()

◆ prepareSimplification()

◆ rewind()

◆ rewindEditBuffer()

◆ setInterruptionChecker()

◆ updateChangedAttributes()

◆ updateFeatureGeometry()

◆ useAddedFeature()

◆ useChangedAttributeFeature()

Member Data Documentation

◆ mChangedFeaturesIterator

◆ mChangedFeaturesRequest

◆ mDistanceWithin

◆ mDistanceWithinEngine

◆ mDistanceWithinGeom

◆ mExpressionFieldInfo

◆ mFetchAddedFeaturesIt

◆ mFetchChangedGeomIt

◆ mFetchConsidered

◆ mFetchedFid

◆ mFetchJoinInfo

◆ mFilterRect

◆ mHasValidTransform

◆ mHasVirtualAttributes

◆ mProviderIterator

◆ mProviderRequest

◆ mTransform