QGIS API Documentation 3.35.0-Master (f6e073f0eed)
Loading...
Searching...
No Matches
qgsfeaturerequest.h
Go to the documentation of this file.
1/***************************************************************************
2 qgsfeaturerequest.h
3 ---------------------
4 begin : Mai 2012
5 copyright : (C) 2012 by Martin Dobias
6 email : wonder dot sk at gmail dot com
7 ***************************************************************************
8 * *
9 * This program is free software; you can redistribute it and/or modify *
10 * it under the terms of the GNU General Public License as published by *
11 * the Free Software Foundation; either version 2 of the License, or *
12 * (at your option) any later version. *
13 * *
14 ***************************************************************************/
15#ifndef QGSFEATUREREQUEST_H
16#define QGSFEATUREREQUEST_H
17
18#include "qgis_core.h"
19#include "qgis_sip.h"
20#include <QFlags>
21#include <QList>
22#include <memory>
23
24#include "qgis.h"
25#include "qgsfeature.h"
26#include "qgsrectangle.h"
27#include "qgsexpression.h"
29#include "qgssimplifymethod.h"
32
33
83class CORE_EXPORT QgsFeatureRequest
84{
85 public:
86
109 class CORE_EXPORT OrderByClause
110 {
111 public:
112
121 OrderByClause( const QString &expression, bool ascending = true );
122
130 OrderByClause( const QString &expression, bool ascending, bool nullsfirst );
131
140 OrderByClause( const QgsExpression &expression, bool ascending = true );
141
149 OrderByClause( const QgsExpression &expression, bool ascending, bool nullsfirst );
150
155 QgsExpression expression() const;
156
163 bool prepare( QgsExpressionContext *context );
164
169 bool ascending() const;
170
174 void setAscending( bool ascending );
175
180 bool nullsFirst() const;
181
185 void setNullsFirst( bool nullsFirst );
186
190 QString dump() const;
191
192 // friend inline int qHash(const OrderByClause &a) { return qHash(a.mExpression.expression()) ^ qHash(a.mAscending) ^ qHash( a.mNullsFirst); }
193
194 bool operator==( const OrderByClause &v ) const
195 {
196 return mExpression == v.mExpression &&
197 mAscending == v.mAscending &&
198 mNullsFirst == v.mNullsFirst;
199 }
200
201 bool operator!=( const OrderByClause &v ) const
202 {
203 return !( v == *this );
204 }
205
206 private:
207 QgsExpression mExpression;
208 bool mAscending;
209 bool mNullsFirst;
210 };
211
212
219 class OrderBy : public QList<QgsFeatureRequest::OrderByClause>
220 {
221 public:
222
226 CORE_EXPORT OrderBy();
227
231 CORE_EXPORT OrderBy( const QList<QgsFeatureRequest::OrderByClause> &other );
232
239 QList<QgsFeatureRequest::OrderByClause> CORE_EXPORT list() const;
240
244 void CORE_EXPORT save( QDomElement &elem ) const;
245
249 void CORE_EXPORT load( const QDomElement &elem );
250
255 QSet<QString> CORE_EXPORT usedAttributes() const;
256
261 QSet<int> CORE_EXPORT usedAttributeIndices( const QgsFields &fields ) const;
262
266 QString CORE_EXPORT dump() const;
267 };
268
272 static const QString ALL_ATTRIBUTES;
273
277 explicit QgsFeatureRequest( QgsFeatureId fid );
279 explicit QgsFeatureRequest( const QgsFeatureIds &fids );
280
288 explicit QgsFeatureRequest( const QgsRectangle &rectangle );
289
291 explicit QgsFeatureRequest( const QgsExpression &expr, const QgsExpressionContext &context = QgsExpressionContext() );
295 QgsFeatureRequest &operator=( const QgsFeatureRequest &rh );
296
298
310 Qgis::FeatureRequestFilterType filterType() const { return mFilter; }
311
324 Qgis::SpatialFilterType spatialFilterType() const { return mSpatialFilter; }
325
338 QgsFeatureRequest &setFilterRect( const QgsRectangle &rectangle );
339
355 QgsRectangle filterRect() const;
356
372 QgsFeatureRequest &setDistanceWithin( const QgsGeometry &geometry, double distance );
373
388 QgsGeometry referenceGeometry() const { return mReferenceGeometry; }
389
398 std::shared_ptr< QgsGeometryEngine > referenceGeometryEngine() const SIP_SKIP { return mReferenceGeometryEngine; }
399
411 double distanceWithin() const { return mDistanceWithin; }
412
421 QgsFeatureRequest &setFilterFid( QgsFeatureId fid );
422
429 QgsFeatureId filterFid() const { return mFilterFid; }
430
439 QgsFeatureRequest &setFilterFids( const QgsFeatureIds &fids );
440
447 const QgsFeatureIds &filterFids() const { return mFilterFids; }
448
455 QgsFeatureRequest &setInvalidGeometryCheck( Qgis::InvalidGeometryCheck check );
456
461 Qgis::InvalidGeometryCheck invalidGeometryCheck() const { return mInvalidGeometryFilter; }
462
469#ifndef SIP_RUN
470 QgsFeatureRequest &setInvalidGeometryCallback( const std::function< void( const QgsFeature & )> &callback );
471#else
472 QgsFeatureRequest &setInvalidGeometryCallback( SIP_PYCALLABLE / AllowNone / );
473 % MethodCode
474 Py_BEGIN_ALLOW_THREADS
475
476 sipCpp->setInvalidGeometryCallback( [a0]( const QgsFeature &arg )
477 {
478 SIP_BLOCK_THREADS
479 Py_XDECREF( sipCallMethod( NULL, a0, "D", &arg, sipType_QgsFeature, NULL ) );
480 SIP_UNBLOCK_THREADS
481 } );
482
483 sipRes = sipCpp;
484
485 Py_END_ALLOW_THREADS
486 % End
487#endif
488
495 std::function< void( const QgsFeature & ) > invalidGeometryCallback() const { return mInvalidGeometryCallback; } SIP_SKIP
496
506 QgsFeatureRequest &setFilterExpression( const QString &expression );
507
513 QgsExpression *filterExpression() const { return mFilterExpression.get(); }
514
523 QgsFeatureRequest &combineFilterExpression( const QString &expression );
524
530 QgsExpressionContext *expressionContext() { return &mExpressionContext; }
531
537 QgsFeatureRequest &setExpressionContext( const QgsExpressionContext &context );
538
549 QgsFeatureRequest &disableFilter() { mFilter = Qgis::FeatureRequestFilterType::NoFilter; mFilterExpression.reset(); return *this; }
550
561 QgsFeatureRequest &addOrderBy( const QString &expression, bool ascending = true );
562
571 QgsFeatureRequest &addOrderBy( const QString &expression, bool ascending, bool nullsfirst );
572
577 OrderBy orderBy() const;
578
583 QgsFeatureRequest &setOrderBy( const OrderBy &orderBy );
584
590 QgsFeatureRequest &setLimit( long long limit );
591
596#ifndef SIP_RUN
597 long long limit() const { return mLimit; }
598#else
599 long long limit() const;
600#endif
601
607 QgsFeatureRequest &setFlags( Qgis::FeatureRequestFlags flags );
608
614 Qgis::FeatureRequestFlags flags() const { return mFlags; }
615
632 QgsFeatureRequest &setSubsetOfAttributes( const QgsAttributeList &attrs );
633
649 QgsFeatureRequest &setNoAttributes();
650
664 QgsAttributeList subsetOfAttributes() const { return mAttrs; }
665
677 QgsFeatureRequest &setSubsetOfAttributes( const QStringList &attrNames, const QgsFields &fields );
678
690 QgsFeatureRequest &setSubsetOfAttributes( const QSet<QString> &attrNames, const QgsFields &fields );
691
697 QgsFeatureRequest &setSimplifyMethod( const QgsSimplifyMethod &simplifyMethod );
698
704 const QgsSimplifyMethod &simplifyMethod() const { return mSimplifyMethod; }
705
713 QgsCoordinateReferenceSystem destinationCrs() const;
714
721 QgsCoordinateTransformContext transformContext() const;
722
745 QgsFeatureRequest &setDestinationCrs( const QgsCoordinateReferenceSystem &crs, const QgsCoordinateTransformContext &context );
746
754#ifndef SIP_RUN
755 QgsFeatureRequest &setTransformErrorCallback( const std::function< void( const QgsFeature & )> &callback );
756#else
757 QgsFeatureRequest &setTransformErrorCallback( SIP_PYCALLABLE / AllowNone / );
758 % MethodCode
759 Py_BEGIN_ALLOW_THREADS
760
761 sipCpp->setTransformErrorCallback( [a0]( const QgsFeature &arg )
762 {
763 SIP_BLOCK_THREADS
764 Py_XDECREF( sipCallMethod( NULL, a0, "D", &arg, sipType_QgsFeature, NULL ) );
765 SIP_UNBLOCK_THREADS
766 } );
767
768 sipRes = sipCpp;
769
770 Py_END_ALLOW_THREADS
771 % End
772#endif
773
781 std::function< void( const QgsFeature & ) > transformErrorCallback() const { return mTransformErrorCallback; } SIP_SKIP
782
783
792 bool acceptFeature( const QgsFeature &feature );
793
802 Q_DECL_DEPRECATED int connectionTimeout() const SIP_DEPRECATED;
803
812 Q_DECL_DEPRECATED QgsFeatureRequest &setConnectionTimeout( int connectionTimeout ) SIP_DEPRECATED;
813
823 int timeout() const;
824
834 QgsFeatureRequest &setTimeout( int timeout );
835
849 bool requestMayBeNested() const;
850
864 QgsFeatureRequest &setRequestMayBeNested( bool requestMayBeNested );
865
877 void setFeedback( QgsFeedback *feedback );
878
887 QgsFeedback *feedback() const;
888
889 protected:
890
894 Qgis::FeatureRequestFilterType mFilter = Qgis::FeatureRequestFilterType::NoFilter;
895
901 Qgis::SpatialFilterType mSpatialFilter = Qgis::SpatialFilterType::NoFilter;
902
906 QgsRectangle mFilterRect;
907
911 QgsGeometry mReferenceGeometry;
912
916 std::shared_ptr< QgsGeometryEngine > mReferenceGeometryEngine;
917
921 double mDistanceWithin = 0;
922
923 QgsFeatureId mFilterFid = -1;
924 QgsFeatureIds mFilterFids;
925 std::unique_ptr< QgsExpression > mFilterExpression;
926 QgsExpressionContext mExpressionContext;
927 Qgis::FeatureRequestFlags mFlags;
929 QgsSimplifyMethod mSimplifyMethod;
930 long long mLimit = -1;
931 OrderBy mOrderBy;
932 Qgis::InvalidGeometryCheck mInvalidGeometryFilter = Qgis::InvalidGeometryCheck::NoCheck;
933 std::function< void( const QgsFeature & ) > mInvalidGeometryCallback;
934 std::function< void( const QgsFeature & ) > mTransformErrorCallback;
937 int mTimeout = -1;
938 int mRequestMayBeNested = false;
939 QgsFeedback *mFeedback = nullptr;
940};
941
942
945
951{
952 public:
954
955
956 // IMPORTANT -- do NOT remove the /TransferBack/ annotation here -- while it looks completely wrong, it's
957 // required for Python data providers to work correctly! Argh!
958
965
966 // IMPORTANT -- do NOT remove the /TransferBack/ annotation here -- while it looks completely wrong, it's
967 // required for Python data providers to work correctly! Argh!
968
969 protected:
970 void iteratorOpened( QgsAbstractFeatureIterator *it );
971 void iteratorClosed( QgsAbstractFeatureIterator *it );
972
973 QSet< QgsAbstractFeatureIterator * > mActiveIterators;
974
975 template<typename> friend class QgsAbstractFeatureIteratorFromSource;
976};
977
978#endif // QGSFEATUREREQUEST_H
The Qgis class provides global constants for use throughout the application.
Definition qgis.h:54
FeatureRequestFilterType
Types of feature request filters.
Definition qgis.h:1743
@ NoFilter
No filter is applied.
SpatialFilterType
Feature request spatial filter types.
Definition qgis.h:1772
InvalidGeometryCheck
Methods for handling of features with invalid geometries.
Definition qgis.h:1759
Helper template that cares of two things: 1.
Internal feature iterator to be implemented within data providers.
Base class that can be used for any class that is capable of returning features.
QSet< QgsAbstractFeatureIterator * > mActiveIterators
virtual QgsFeatureIterator getFeatures(const QgsFeatureRequest &request=QgsFeatureRequest())=0
Gets an iterator for features matching the specified request.
This class represents a coordinate reference system (CRS).
Contains information about the context in which a coordinate transform is executed.
Expression contexts are used to encapsulate the parameters around which a QgsExpression should be eva...
Class for parsing and evaluation of expressions (formerly called "search strings").
Wrapper for iterator of features from vector data provider or vector layer.
The OrderByClause class represents an order by clause for a QgsFeatureRequest.
bool operator==(const OrderByClause &v) const
bool operator!=(const OrderByClause &v) const
Represents a list of OrderByClauses, with the most important first and the least important last.
CORE_EXPORT OrderBy()
Create a new empty order by.
This class wraps a request for features to a vector layer (or directly its vector data provider).
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 ...
std::function< void(const QgsFeature &) > invalidGeometryCallback() const
Returns the callback function to use when encountering an invalid geometry and invalidGeometryCheck()...
Qgis::FeatureRequestFilterType filterType() const
Returns the attribute/ID filter type which is currently set on this request.
QgsGeometry referenceGeometry() const
Returns the reference geometry used for spatial filtering of features.
static const QString ALL_ATTRIBUTES
A special attribute that if set matches all attributes.
Qgis::FeatureRequestFlags flags() const
Returns the flags which affect how features are fetched.
QgsFeatureRequest & disableFilter()
Disables any attribute/ID filtering.
QgsExpression * filterExpression() const
Returns the filter expression (if set).
const QgsSimplifyMethod & simplifyMethod() const
Returns the simplification method for geometries that will be fetched.
std::shared_ptr< QgsGeometryEngine > referenceGeometryEngine() const
Returns the reference geometry engine used for spatial filtering of features.
Qgis::SpatialFilterType spatialFilterType() const
Returns the spatial filter type which is currently set on this request.
double distanceWithin() const
Returns the maximum distance from the referenceGeometry() of fetched features, if spatialFilterType()...
QgsAttributeList subsetOfAttributes() const
Returns the subset of attributes which at least need to be fetched.
Qgis::InvalidGeometryCheck invalidGeometryCheck() const
Returns the invalid geometry checking behavior.
const QgsFeatureIds & filterFids() const
Returns the feature IDs that should be fetched.
QgsFeatureId filterFid() const
Returns the feature ID that should be fetched.
The feature class encapsulates a single feature including its unique ID, geometry and a list of field...
Definition qgsfeature.h:56
Base class for feedback objects to be used for cancellation of something running in a worker thread.
Definition qgsfeedback.h:44
Container of fields for a vector layer.
Definition qgsfields.h:45
A geometry engine is a low-level representation of a QgsAbstractGeometry object, optimised for use wi...
A geometry is the spatial representation of a feature.
A rectangle specified with double values.
This class contains information about how to simplify geometries fetched from a QgsFeatureIterator.
#define SIP_DEPRECATED
Definition qgis_sip.h:106
#define SIP_SKIP
Definition qgis_sip.h:126
#define SIP_TRANSFERBACK
Definition qgis_sip.h:48
QSet< QgsFeatureId > QgsFeatureIds
qint64 QgsFeatureId
64 bit feature ids negative numbers are used for uncommitted/newly added features
QList< int > QgsAttributeList
Definition qgsfield.h:27
const QgsCoordinateReferenceSystem & crs