38 if ( mUseCachedFeatures )
40 if ( mFeatureIterator != mCachedFeatures.constEnd() )
42 f = mFeatureIterator->mFeature;
196 Q_UNUSED( simplifyMethod )
200void QgsAbstractFeatureIterator::setupOrderBy(
const QList<QgsFeatureRequest::OrderByClause> &orderBys )
203 if ( !orderBys.isEmpty() && !prepareOrderBy( orderBys ) )
208 QList<QgsFeatureRequest::OrderByClause> preparedOrderBys( orderBys );
209 QList<QgsFeatureRequest::OrderByClause>::iterator orderByIt( preparedOrderBys.begin() );
214 orderByIt->prepare( expressionContext );
216 while ( ++orderByIt != preparedOrderBys.end() );
220 indexedFeature.
mIndexes.resize( preparedOrderBys.size() );
224 expressionContext->setFeature( indexedFeature.
mFeature );
226 const auto constPreparedOrderBys = preparedOrderBys;
229 indexedFeature.
mIndexes.replace( i++, orderBy.expression().evaluate( expressionContext ) );
235 mCachedFeatures.append( indexedFeature );
238 std::sort( mCachedFeatures.begin(), mCachedFeatures.end(), QgsExpressionSorter( preparedOrderBys ) );
240 mFeatureIterator = mCachedFeatures.constBegin();
241 mUseCachedFeatures =
true;
249 Q_UNUSED( methodType )
253bool QgsAbstractFeatureIterator::prepareOrderBy(
const QList<QgsFeatureRequest::OrderByClause> &orderBys )
267 if (
this != &other )
@ Fids
Filter using feature IDs.
@ Expression
Filter using expression.
@ DistanceWithin
Filter by distance to reference geometry.
@ BoundingBox
Filter using a bounding box.
@ NoFilter
No spatial filtering of features.
@ Forward
Forward transform (from source to destination)
@ Reverse
Reverse/inverse transform (from destination to source)
RequestToSourceCrsResult
Possible results from the updateRequestToSourceCrs() method.
@ Success
Request was successfully updated to the source CRS, or no changes were required.
@ DistanceWithinMustBeCheckedManually
The distance within request cannot be losslessly updated to the source CRS, and callers will need to ...
bool mZombie
A feature iterator may be closed already but still be serving features from the cache.
virtual bool nextFeatureFilterFids(QgsFeature &f)
By default, the iterator will fetch all features and check if the id is in the request.
void geometryToDestinationCrs(QgsFeature &feature, const QgsCoordinateTransform &transform) const
Transforms feature's geometry according to the specified coordinate transform.
QgsRectangle filterRectToSourceCrs(const QgsCoordinateTransform &transform) const
Returns a rectangle representing the original request's QgsFeatureRequest::filterRect().
virtual void setInterruptionChecker(QgsFeedback *interruptionChecker)
Attach an object that can be queried regularly by the iterator to check if it must stopped.
virtual bool fetchFeature(QgsFeature &f)=0
If you write a feature iterator for your provider, this is the method you need to implement!...
long long mFetchedCount
Number of features already fetched by iterator.
virtual bool prepareSimplification(const QgsSimplifyMethod &simplifyMethod)
Setup the simplification of geometries to fetch using the specified simplify method.
void deref()
Remove reference, delete if refs == 0.
QgsFeatureRequest mRequest
A copy of the feature request.
QgsAbstractFeatureIterator(const QgsFeatureRequest &request)
base class constructor - stores the iteration parameters
RequestToSourceCrsResult updateRequestToSourceCrs(QgsFeatureRequest &request, const QgsCoordinateTransform &transform) const
Update a QgsFeatureRequest so that spatial filters are transformed to the source's coordinate referen...
bool compileFailed() const
Indicator if there was an error when sending the compiled query to the server.
virtual bool isValid() const
Returns if this iterator is valid.
int refs
reference counting (to allow seamless copying of QgsFeatureIterator instances)
virtual bool nextFeature(QgsFeature &f)
Fetch next feature and stores in f, returns true on success.
virtual bool nextFeatureFilterExpression(QgsFeature &f)
By default, the iterator will fetch all features and check if the feature matches the expression.
Custom exception class for Coordinate Reference System related exceptions.
Expression contexts are used to encapsulate the parameters around which a QgsExpression should be eva...
void setFeature(const QgsFeature &feature)
Convenience function for setting a feature for the context.
QVariant evaluate()
Evaluate the feature and return the result.
Wrapper for iterator of features from vector data provider or vector layer.
QgsAbstractFeatureIterator * mIter
QgsFeatureIterator & operator=(const QgsFeatureIterator &other)
bool isValid() const
Will return if this iterator is valid.
The OrderByClause class represents an order by clause for a QgsFeatureRequest.
This class wraps a request for features to a vector layer (or directly its vector data provider).
QgsRectangle filterRect() const
Returns the rectangle from which features will be taken.
QgsFeedback * feedback() const
Returns the feedback object that can be queried regularly by the iterator to check if it should be ca...
long long limit() const
Returns the maximum number of features to request, or -1 if no limit set.
QgsExpressionContext * expressionContext()
Returns the expression context used to evaluate filter expressions.
std::function< void(const QgsFeature &) > transformErrorCallback() const
Returns the callback function to use when encountering a transform error when iterating features and ...
OrderBy orderBy() const
Returns a list of order by clauses specified for this feature request.
Qgis::FeatureRequestFilterType filterType() const
Returns the attribute/ID filter type which is currently set on this request.
QgsExpression * filterExpression() const
Returns the filter expression (if set).
const QgsSimplifyMethod & simplifyMethod() const
Returns the simplification method for geometries that will be fetched.
Qgis::SpatialFilterType spatialFilterType() const
Returns the spatial filter type which is currently set on this request.
const QgsFeatureIds & filterFids() const
Returns the feature IDs that should be fetched.
QgsFeatureRequest & setFilterRect(const QgsRectangle &rectangle)
Sets the rectangle from which features will be taken.
The feature class encapsulates a single feature including its unique ID, geometry and a list of field...
void clearGeometry()
Removes any geometry associated with the feature.
bool hasGeometry() const
Returns true if the feature has an associated geometry.
void setGeometry(const QgsGeometry &geometry)
Set the feature's geometry.
Base class for feedback objects to be used for cancellation of something running in a worker thread.
bool isCanceled() const
Tells whether the operation has been canceled already.
A geometry is the spatial representation of a feature.
Qgis::GeometryOperationResult transform(const QgsCoordinateTransform &ct, Qgis::TransformDirection direction=Qgis::TransformDirection::Forward, bool transformZ=false)
Transforms this geometry as described by the coordinate transform ct.
Temporarily used structure to cache order by information.
QVector< QVariant > mIndexes
A rectangle specified with double values.
bool isNull() const
Test if the rectangle is null (holding no spatial information).
This class contains information about how to simplify geometries fetched from a QgsFeatureIterator.
#define BUILTIN_UNREACHABLE