Uses another iterator as backend and writes features to the cache. More...
#include <qgscachedfeatureiterator.h>
Inheritance diagram for QgsCachedFeatureWriterIterator:
Public Member Functions | |
| QgsCachedFeatureWriterIterator (QgsVectorLayerCache *vlCache, const QgsFeatureRequest &featureRequest) | |
| This constructor creates a feature iterator, which queries the backend and caches retrieved features. More... | |
| bool | close () override |
| Close this iterator. More... | |
| bool | rewind () override |
| Rewind to the beginning of the iterator. More... | |
 Public Member Functions inherited from QgsAbstractFeatureIterator | |
| QgsAbstractFeatureIterator (const QgsFeatureRequest &request) | |
| base class constructor - stores the iteration parameters More... | |
| virtual | ~QgsAbstractFeatureIterator ()=default |
| destructor makes sure that the iterator is closed properly More... | |
| bool | compileFailed () const |
| Indicator if there was an error when sending the compiled query to the server. More... | |
| CompileStatus | compileStatus () const |
| Returns the status of expression compilation for filter expression requests. More... | |
| virtual bool | isValid () const |
| Returns if this iterator is valid. More... | |
| virtual bool | nextFeature (QgsFeature &f) |
fetch next feature, return true on success More... | |
| virtual void | setInterruptionChecker (QgsFeedback *interruptionChecker) |
| Attach an object that can be queried regularly by the iterator to check if it must stopped. More... | |
Protected Member Functions | |
| bool | fetchFeature (QgsFeature &f) override |
| Implementation for fetching a feature. More... | |
| Protected Member Functions inherited from QgsAbstractFeatureIterator | |
| void | deref () |
| Remove reference, delete if refs == 0. More... | |
| QgsRectangle | filterRectToSourceCrs (const QgsCoordinateTransform &transform) const SIP_THROW(QgsCsException) |
| Returns a rectangle representing the original request's QgsFeatureRequest::filterRect(). More... | |
| void | geometryToDestinationCrs (QgsFeature &feature, const QgsCoordinateTransform &transform) const |
| Transforms feature's geometry according to the specified coordinate transform. More... | |
| virtual bool | nextFeatureFilterExpression (QgsFeature &f) |
| By default, the iterator will fetch all features and check if the feature matches the expression. More... | |
| virtual bool | nextFeatureFilterFids (QgsFeature &f) |
| By default, the iterator will fetch all features and check if the id is in the request. More... | |
| virtual bool | prepareSimplification (const QgsSimplifyMethod &simplifyMethod) |
| Setup the simplification of geometries to fetch using the specified simplify method. More... | |
| void | ref () |
| Add reference. More... | |
Additional Inherited Members | |
| Public Types inherited from QgsAbstractFeatureIterator | |
| enum | CompileStatus { NoCompilation, PartiallyCompiled, Compiled } |
| Status of expression compilation for filter expression requests. More... | |
| Protected Attributes inherited from QgsAbstractFeatureIterator | |
| bool | mClosed = false |
Sets to true, as soon as the iterator is closed. More... | |
| bool | mCompileFailed = false |
| CompileStatus | mCompileStatus = NoCompilation |
| Status of compilation of filter expression. More... | |
| long | mFetchedCount = 0 |
| Number of features already fetched by iterator. More... | |
| QgsFeatureRequest | mRequest |
| A copy of the feature request. More... | |
| bool | mValid = true |
| An invalid state of a feature iterator indicates that there was a problem with even getting it up and running. More... | |
| bool | mZombie = false |
| A feature iterator may be closed already but still be serving features from the cache. More... | |
| int | refs = 0 |
| reference counting (to allow seamless copying of QgsFeatureIterator instances) More... | |
Detailed Description
Uses another iterator as backend and writes features to the cache.
Definition at line 92 of file qgscachedfeatureiterator.h.
Constructor & Destructor Documentation
◆ QgsCachedFeatureWriterIterator()
| QgsCachedFeatureWriterIterator::QgsCachedFeatureWriterIterator | ( | QgsVectorLayerCache * | vlCache, |
| const QgsFeatureRequest & | featureRequest | ||
| ) |
This constructor creates a feature iterator, which queries the backend and caches retrieved features.
- Parameters
-
vlCache The vector layer cache to use featureRequest The feature request to answer
Definition at line 107 of file qgscachedfeatureiterator.cpp.
Member Function Documentation
◆ close()
|
overridevirtual |
Close this iterator.
No further features will be available.
- Returns
trueif successful
Implements QgsAbstractFeatureIterator.
Definition at line 164 of file qgscachedfeatureiterator.cpp.
◆ fetchFeature()
|
overrideprotectedvirtual |
Implementation for fetching a feature.
- Parameters
-
f Will write to this feature
- Returns
- bool
trueif the operation was OK
- See also
- bool getFeature( QgsFeature& f )
Implements QgsAbstractFeatureIterator.
Definition at line 134 of file qgscachedfeatureiterator.cpp.
◆ rewind()
|
overridevirtual |
Rewind to the beginning of the iterator.
- Returns
- bool
trueif the operation was OK
Implements QgsAbstractFeatureIterator.
Definition at line 158 of file qgscachedfeatureiterator.cpp.
The documentation for this class was generated from the following files:
- /build/qgis-3.16.0+99unstable/src/core/qgscachedfeatureiterator.h
- /build/qgis-3.16.0+99unstable/src/core/qgscachedfeatureiterator.cpp
