QGIS API Documentation  2.17.0-Master (bf77d09)
Classes | Public Member Functions | Protected Member Functions | Protected Attributes | List of all members
QgsVectorLayerFeatureIterator Class Reference

#include <qgsvectorlayerfeatureiterator.h>

Inheritance diagram for QgsVectorLayerFeatureIterator:
Inheritance graph
[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 ()
 
virtual bool close () override
 end of iterating: free the resources / lock More...
 
virtual bool rewind () override
 reset the iterator to the starting position More...
 
virtual void setInterruptionChecker (QgsInterruptionChecker *interruptionChecker) override
 Attach an object that can be queried regularly by the iterator to check if it must stopped. More...
 
- Public Member Functions inherited from QgsAbstractFeatureIteratorFromSource< QgsVectorLayerFeatureSource >
 QgsAbstractFeatureIteratorFromSource (QgsVectorLayerFeatureSource *source, bool ownSource, const QgsFeatureRequest &request)
 
 ~QgsAbstractFeatureIteratorFromSource ()
 
- Public Member Functions inherited from QgsAbstractFeatureIterator
 QgsAbstractFeatureIterator (const QgsFeatureRequest &request)
 base class constructor - stores the iteration parameters More...
 
virtual ~QgsAbstractFeatureIterator ()
 destructor makes sure that the iterator is closed properly More...
 
CompileStatus compileStatus () const
 Returns the status of expression compilation for filter expression requests. More...
 
virtual bool nextFeature (QgsFeature &f)
 fetch next feature, return true on success More...
 

Protected Member Functions

void addExpressionAttribute (QgsFeature &f, int attrIndex)
 Adds an expression based attribute to a feature. More...
 
void addJoinedAttributes (QgsFeature &f)
 
void addVirtualAttributes (QgsFeature &f)
 Adds attributes that don't source from the provider but are added inside QGIS Includes. More...
 
virtual bool fetchFeature (QgsFeature &feature) override
 fetch next feature, return true on success More...
 
bool fetchNextAddedFeature (QgsFeature &f)
 
bool fetchNextChangedAttributeFeature (QgsFeature &f)
 
bool fetchNextChangedGeomFeature (QgsFeature &f)
 
bool nextFeatureFid (QgsFeature &f)
 
virtual 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. More...
 
void prepareExpression (int fieldIdx)
 
void prepareField (int fieldIdx)
 
void prepareFields ()
 
void prepareJoin (int fieldIdx)
 
virtual bool prepareSimplification (const QgsSimplifyMethod &simplifyMethod) override
 Setup the simplification of geometries to fetch using the specified simplify method. More...
 
void rewindEditBuffer ()
 
void updateChangedAttributes (QgsFeature &f)
 Update feature with uncommited attribute updates. More...
 
void updateFeatureGeometry (QgsFeature &f)
 Update feature with uncommited geometry updates. More...
 
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() More...
 
- Protected Member Functions inherited from QgsAbstractFeatureIterator
void deref ()
 remove reference, delete if refs == 0 More...
 
virtual bool nextFeatureFilterFids (QgsFeature &f)
 By default, the iterator will fetch all features and check if the id is in the request. More...
 
void ref ()
 add reference More...
 

Protected Attributes

QgsFeatureIterator mChangedFeaturesIterator
 
QgsFeatureRequest mChangedFeaturesRequest
 
QMap< int, QgsExpression * > mExpressionFieldInfo
 
QgsFeatureMap::ConstIterator mFetchAddedFeaturesIt
 
QgsGeometryMap::ConstIterator mFetchChangedGeomIt
 
QSet< QgsFeatureIdmFetchConsidered
 
bool mFetchedFid
 
QMap< const QgsVectorJoinInfo *, FetchJoinInfomFetchJoinInfo
 Information about joins used in the current select() statement. More...
 
bool mHasVirtualAttributes
 
QgsFeatureIterator mProviderIterator
 
QgsFeatureRequest mProviderRequest
 
- Protected Attributes inherited from QgsAbstractFeatureIteratorFromSource< QgsVectorLayerFeatureSource >
bool mOwnSource
 
QgsVectorLayerFeatureSourcemSource
 
- Protected Attributes inherited from QgsAbstractFeatureIterator
bool mClosed
 Set to true, as soon as the iterator is closed. More...
 
CompileStatus mCompileStatus
 Status of compilation of filter expression. More...
 
long mFetchedCount
 Number of features already fetched by iterator. More...
 
QgsFeatureRequest mRequest
 A copy of the feature request. More...
 
bool mZombie
 A feature iterator may be closed already but still be serving features from the cache. More...
 
int refs
 reference counting (to allow seamless copying of QgsFeatureIterator instances) TODO QGIS3: make this private More...
 

Additional Inherited Members

- Public Types inherited from QgsAbstractFeatureIterator
enum  CompileStatus { NoCompilation, PartiallyCompiled, Compiled }
 Status of expression compilation for filter expression requests. More...
 

Detailed Description

Definition at line 74 of file qgsvectorlayerfeatureiterator.h.

Constructor & Destructor Documentation

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

Definition at line 95 of file qgsvectorlayerfeatureiterator.cpp.

QgsVectorLayerFeatureIterator::~QgsVectorLayerFeatureIterator ( )

Definition at line 200 of file qgsvectorlayerfeatureiterator.cpp.

Member Function Documentation

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

Adds an expression based attribute to a feature.

Parameters
ffeature
attrIndexattribute index
Note
added in QGIS 2.14
not available in Python bindings

Definition at line 663 of file qgsvectorlayerfeatureiterator.cpp.

void QgsVectorLayerFeatureIterator::addJoinedAttributes ( QgsFeature f)
protected
Note
not available in Python bindings

Definition at line 603 of file qgsvectorlayerfeatureiterator.cpp.

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
fThe feature will be modified
Note
not available in Python bindings

Definition at line 623 of file qgsvectorlayerfeatureiterator.cpp.

bool QgsVectorLayerFeatureIterator::close ( )
overridevirtual

end of iterating: free the resources / lock

Implements QgsAbstractFeatureIterator.

Definition at line 313 of file qgsvectorlayerfeatureiterator.cpp.

bool QgsVectorLayerFeatureIterator::fetchFeature ( QgsFeature feature)
overrideprotectedvirtual

fetch next feature, return true on success

Implements QgsAbstractFeatureIterator.

Definition at line 209 of file qgsvectorlayerfeatureiterator.cpp.

bool QgsVectorLayerFeatureIterator::fetchNextAddedFeature ( QgsFeature f)
protected
Note
not available in Python bindings

Definition at line 332 of file qgsvectorlayerfeatureiterator.cpp.

bool QgsVectorLayerFeatureIterator::fetchNextChangedAttributeFeature ( QgsFeature f)
protected
Note
not available in Python bindings

Definition at line 404 of file qgsvectorlayerfeatureiterator.cpp.

bool QgsVectorLayerFeatureIterator::fetchNextChangedGeomFeature ( QgsFeature f)
protected
Note
not available in Python bindings

Definition at line 377 of file qgsvectorlayerfeatureiterator.cpp.

bool QgsVectorLayerFeatureIterator::nextFeatureFid ( QgsFeature f)
protected
Note
not available in Python bindings

Definition at line 786 of file qgsvectorlayerfeatureiterator.cpp.

virtual 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 95 of file qgsvectorlayerfeatureiterator.h.

void QgsVectorLayerFeatureIterator::prepareExpression ( int  fieldIdx)
protected
Note
not available in Python bindings

Definition at line 521 of file qgsvectorlayerfeatureiterator.cpp.

void QgsVectorLayerFeatureIterator::prepareField ( int  fieldIdx)
protected
Note
not available in Python bindings

Definition at line 581 of file qgsvectorlayerfeatureiterator.cpp.

void QgsVectorLayerFeatureIterator::prepareFields ( )
protected
Note
not available in Python bindings

Definition at line 557 of file qgsvectorlayerfeatureiterator.cpp.

void QgsVectorLayerFeatureIterator::prepareJoin ( int  fieldIdx)
protected
Note
not available in Python bindings

Definition at line 475 of file qgsvectorlayerfeatureiterator.cpp.

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 672 of file qgsvectorlayerfeatureiterator.cpp.

bool QgsVectorLayerFeatureIterator::rewind ( )
overridevirtual

reset the iterator to the starting position

Implements QgsAbstractFeatureIterator.

Definition at line 295 of file qgsvectorlayerfeatureiterator.cpp.

void QgsVectorLayerFeatureIterator::rewindEditBuffer ( )
protected
Note
not available in Python bindings

Definition at line 467 of file qgsvectorlayerfeatureiterator.cpp.

void QgsVectorLayerFeatureIterator::setInterruptionChecker ( QgsInterruptionChecker 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
added in QGIS 2.16
not available in Python bindings

Reimplemented from QgsAbstractFeatureIterator.

Definition at line 326 of file qgsvectorlayerfeatureiterator.cpp.

void QgsVectorLayerFeatureIterator::updateChangedAttributes ( QgsFeature f)
protected

Update feature with uncommited attribute updates.

Note
not available in Python bindings

Definition at line 829 of file qgsvectorlayerfeatureiterator.cpp.

void QgsVectorLayerFeatureIterator::updateFeatureGeometry ( QgsFeature f)
protected

Update feature with uncommited geometry updates.

Note
not available in Python bindings

Definition at line 852 of file qgsvectorlayerfeatureiterator.cpp.

void QgsVectorLayerFeatureIterator::useAddedFeature ( const QgsFeature src,
QgsFeature f 
)
protected
Note
not available in Python bindings

Definition at line 356 of file qgsvectorlayerfeatureiterator.cpp.

void QgsVectorLayerFeatureIterator::useChangedAttributeFeature ( QgsFeatureId  fid,
const QgsGeometry geom,
QgsFeature f 
)
protected
Note
not available in Python bindings

Definition at line 430 of file qgsvectorlayerfeatureiterator.cpp.

Member Data Documentation

QgsFeatureIterator QgsVectorLayerFeatureIterator::mChangedFeaturesIterator
protected

Definition at line 178 of file qgsvectorlayerfeatureiterator.h.

QgsFeatureRequest QgsVectorLayerFeatureIterator::mChangedFeaturesRequest
protected

Definition at line 177 of file qgsvectorlayerfeatureiterator.h.

QMap<int, QgsExpression*> QgsVectorLayerFeatureIterator::mExpressionFieldInfo
protected

Definition at line 191 of file qgsvectorlayerfeatureiterator.h.

QgsFeatureMap::ConstIterator QgsVectorLayerFeatureIterator::mFetchAddedFeaturesIt
protected

Definition at line 183 of file qgsvectorlayerfeatureiterator.h.

QgsGeometryMap::ConstIterator QgsVectorLayerFeatureIterator::mFetchChangedGeomIt
protected

Definition at line 182 of file qgsvectorlayerfeatureiterator.h.

QSet<QgsFeatureId> QgsVectorLayerFeatureIterator::mFetchConsidered
protected

Definition at line 181 of file qgsvectorlayerfeatureiterator.h.

bool QgsVectorLayerFeatureIterator::mFetchedFid
protected

Definition at line 185 of file qgsvectorlayerfeatureiterator.h.

QMap<const QgsVectorJoinInfo*, 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 189 of file qgsvectorlayerfeatureiterator.h.

bool QgsVectorLayerFeatureIterator::mHasVirtualAttributes
protected

Definition at line 193 of file qgsvectorlayerfeatureiterator.h.

QgsFeatureIterator QgsVectorLayerFeatureIterator::mProviderIterator
protected

Definition at line 176 of file qgsvectorlayerfeatureiterator.h.

QgsFeatureRequest QgsVectorLayerFeatureIterator::mProviderRequest
protected

Definition at line 175 of file qgsvectorlayerfeatureiterator.h.


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