QgsFeatureIterator Class Reference

Wrapper for iterator of features from vector data provider or vector layer. More...

#include <qgsfeatureiterator.h>

Public Member Functions
	QgsFeatureIterator ()=default
	Construct invalid iterator.
	QgsFeatureIterator (const QgsFeatureIterator &fi)
	Copy constructor copies the iterator, increases ref.count.
	QgsFeatureIterator (QgsAbstractFeatureIterator *iter)
	Construct a valid iterator.
	~QgsFeatureIterator ()
	Destructor deletes the iterator if it has no more references.
bool	close ()
	Call to end the iteration.
bool	compileFailed () const
	Indicator if there was an error when sending the compiled query to the server.
QgsAbstractFeatureIterator::CompileStatus	compileStatus () const
	Returns the status of expression compilation for filter expression requests.
bool	isClosed () const
	find out whether the iterator is still valid or closed already
bool	isValid () const
	Will return if this iterator is valid.
bool	nextFeature (QgsFeature &f)
	Fetch next feature and stores in f, returns true on success.
QgsFeatureIterator &	operator= (const QgsFeatureIterator &other)
bool	rewind ()
	Resets the iterator to the starting position.
void	setInterruptionChecker (QgsFeedback *interruptionChecker)
	Attach an object that can be queried regularly by the iterator to check if it must stopped.

Protected Attributes
QgsAbstractFeatureIterator *	mIter = nullptr

Friends
bool	operator!= (const QgsFeatureIterator &fi1, const QgsFeatureIterator &fi2)
bool	operator== (const QgsFeatureIterator &fi1, const QgsFeatureIterator &fi2)

Detailed Description

Wrapper for iterator of features from vector data provider or vector layer.

Definition at line 289 of file qgsfeatureiterator.h.

Constructor & Destructor Documentation

QgsFeatureIterator() [1/3]

QgsFeatureIterator::QgsFeatureIterator ( )

default

Construct invalid iterator.

QgsFeatureIterator() [2/3]

QgsFeatureIterator::QgsFeatureIterator ( QgsAbstractFeatureIterator *  iter )

inline

Construct a valid iterator.

Definition at line 387 of file qgsfeatureiterator.h.

QgsFeatureIterator() [3/3]

QgsFeatureIterator::QgsFeatureIterator ( const QgsFeatureIterator &  fi )

inline

Copy constructor copies the iterator, increases ref.count.

Definition at line 394 of file qgsfeatureiterator.h.

~QgsFeatureIterator()

QgsFeatureIterator::~QgsFeatureIterator ( )

inline

Destructor deletes the iterator if it has no more references.

Definition at line 401 of file qgsfeatureiterator.h.

Member Function Documentation

close()

bool QgsFeatureIterator::close ( )

inline

Call to end the iteration.

This frees any resources used by the iterator.

Definition at line 420 of file qgsfeatureiterator.h.

compileFailed()

bool QgsFeatureIterator::compileFailed ( ) const

inline

Indicator if there was an error when sending the compiled query to the server.

This indicates that there is something wrong with the expression compiler.

Since

QGIS 3.2

Definition at line 374 of file qgsfeatureiterator.h.

compileStatus()

QgsAbstractFeatureIterator::CompileStatus QgsFeatureIterator::compileStatus ( ) const

inline

Returns the status of expression compilation for filter expression requests.

Definition at line 366 of file qgsfeatureiterator.h.

isClosed()

bool QgsFeatureIterator::isClosed ( ) const

inline

find out whether the iterator is still valid or closed already

Definition at line 428 of file qgsfeatureiterator.h.

isValid()

bool QgsFeatureIterator::isValid

(

)

const

Will return if this iterator is valid.

An invalid iterator was probably introduced by a failed attempt to acquire a connection or is a default constructed iterator.

See also

isClosed to check if the iterator successfully completed and returned all the features.

Definition at line 278 of file qgsfeatureiterator.cpp.

nextFeature()

bool QgsFeatureIterator::nextFeature ( QgsFeature &  f )

inline

Fetch next feature and stores in f, returns true on success.

Definition at line 407 of file qgsfeatureiterator.h.

operator=()

QgsFeatureIterator & QgsFeatureIterator::operator=

(

const QgsFeatureIterator &

other

)

Definition at line 265 of file qgsfeatureiterator.cpp.

rewind()

bool QgsFeatureIterator::rewind ( )

inline

Resets the iterator to the starting position.

Definition at line 412 of file qgsfeatureiterator.h.

setInterruptionChecker()

void QgsFeatureIterator::setInterruptionChecker ( QgsFeedback *  interruptionChecker )

inline

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.

Note

not available in Python bindings

Definition at line 443 of file qgsfeatureiterator.h.

Friends And Related Symbol Documentation

operator!=

bool operator!= ( const QgsFeatureIterator &  fi1, const QgsFeatureIterator &  fi2  )

friend

Definition at line 438 of file qgsfeatureiterator.h.

operator==

bool operator== ( const QgsFeatureIterator &  fi1, const QgsFeatureIterator &  fi2  )

friend

Definition at line 433 of file qgsfeatureiterator.h.

Member Data Documentation

mIter

QgsAbstractFeatureIterator* QgsFeatureIterator::mIter = nullptr

protected

Definition at line 380 of file qgsfeatureiterator.h.

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

• /home/fischer/src/qgis-3.38/src/core/qgsfeatureiterator.h
• /home/fischer/src/qgis-3.38/src/core/qgsfeatureiterator.cpp