QGIS API Documentation 3.37.0-Master (684a802617f)
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qgsfeaturerequest.h
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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
237 CORE_EXPORT bool operator==( const OrderBy &v ) const;
238
243 CORE_EXPORT bool operator!=( const OrderBy &v ) const;
244
251 QList<QgsFeatureRequest::OrderByClause> CORE_EXPORT list() const;
252
256 void CORE_EXPORT save( QDomElement &elem ) const;
257
261 void CORE_EXPORT load( const QDomElement &elem );
262
267 QSet<QString> CORE_EXPORT usedAttributes() const;
268
273 QSet<int> CORE_EXPORT usedAttributeIndices( const QgsFields &fields ) const;
274
278 QString CORE_EXPORT dump() const;
279 };
280
284 static const QString ALL_ATTRIBUTES;
285
289 explicit QgsFeatureRequest( QgsFeatureId fid );
291 explicit QgsFeatureRequest( const QgsFeatureIds &fids );
292
300 explicit QgsFeatureRequest( const QgsRectangle &rectangle );
301
303 explicit QgsFeatureRequest( const QgsExpression &expr, const QgsExpressionContext &context = QgsExpressionContext() );
307 QgsFeatureRequest &operator=( const QgsFeatureRequest &rh );
308
315 bool compare( const QgsFeatureRequest &other ) const;
316
318
330 Qgis::FeatureRequestFilterType filterType() const { return mFilter; }
331
344 Qgis::SpatialFilterType spatialFilterType() const { return mSpatialFilter; }
345
358 QgsFeatureRequest &setFilterRect( const QgsRectangle &rectangle );
359
375 QgsRectangle filterRect() const;
376
392 QgsFeatureRequest &setDistanceWithin( const QgsGeometry &geometry, double distance );
393
408 QgsGeometry referenceGeometry() const { return mReferenceGeometry; }
409
418 std::shared_ptr< QgsGeometryEngine > referenceGeometryEngine() const SIP_SKIP { return mReferenceGeometryEngine; }
419
431 double distanceWithin() const { return mDistanceWithin; }
432
441 QgsFeatureRequest &setFilterFid( QgsFeatureId fid );
442
449 QgsFeatureId filterFid() const { return mFilterFid; }
450
459 QgsFeatureRequest &setFilterFids( const QgsFeatureIds &fids );
460
467 const QgsFeatureIds &filterFids() const { return mFilterFids; }
468
475 QgsFeatureRequest &setInvalidGeometryCheck( Qgis::InvalidGeometryCheck check );
476
481 Qgis::InvalidGeometryCheck invalidGeometryCheck() const { return mInvalidGeometryFilter; }
482
489#ifndef SIP_RUN
490 QgsFeatureRequest &setInvalidGeometryCallback( const std::function< void( const QgsFeature & )> &callback );
491#else
492 QgsFeatureRequest &setInvalidGeometryCallback( SIP_PYCALLABLE / AllowNone / );
493 % MethodCode
494 Py_BEGIN_ALLOW_THREADS
495
496 sipCpp->setInvalidGeometryCallback( [a0]( const QgsFeature &arg )
497 {
498 SIP_BLOCK_THREADS
499 Py_XDECREF( sipCallMethod( NULL, a0, "D", &arg, sipType_QgsFeature, NULL ) );
500 SIP_UNBLOCK_THREADS
501 } );
502
503 sipRes = sipCpp;
504
505 Py_END_ALLOW_THREADS
506 % End
507#endif
508
515 std::function< void( const QgsFeature & ) > invalidGeometryCallback() const { return mInvalidGeometryCallback; } SIP_SKIP
516
526 QgsFeatureRequest &setFilterExpression( const QString &expression );
527
533 QgsExpression *filterExpression() const { return mFilterExpression.get(); }
534
543 QgsFeatureRequest &combineFilterExpression( const QString &expression );
544
550 QgsExpressionContext *expressionContext() { return &mExpressionContext; }
551
557 QgsFeatureRequest &setExpressionContext( const QgsExpressionContext &context );
558
569 QgsFeatureRequest &disableFilter() { mFilter = Qgis::FeatureRequestFilterType::NoFilter; mFilterExpression.reset(); return *this; }
570
581 QgsFeatureRequest &addOrderBy( const QString &expression, bool ascending = true );
582
591 QgsFeatureRequest &addOrderBy( const QString &expression, bool ascending, bool nullsfirst );
592
597 OrderBy orderBy() const;
598
603 QgsFeatureRequest &setOrderBy( const OrderBy &orderBy );
604
610 QgsFeatureRequest &setLimit( long long limit );
611
616#ifndef SIP_RUN
617 long long limit() const { return mLimit; }
618#else
619 long long limit() const;
620#endif
621
628
634 Qgis::FeatureRequestFlags flags() const { return mFlags; }
635
652 QgsFeatureRequest &setSubsetOfAttributes( const QgsAttributeList &attrs );
653
669 QgsFeatureRequest &setNoAttributes();
670
684 QgsAttributeList subsetOfAttributes() const { return mAttrs; }
685
697 QgsFeatureRequest &setSubsetOfAttributes( const QStringList &attrNames, const QgsFields &fields );
698
710 QgsFeatureRequest &setSubsetOfAttributes( const QSet<QString> &attrNames, const QgsFields &fields );
711
717 QgsFeatureRequest &setSimplifyMethod( const QgsSimplifyMethod &simplifyMethod );
718
724 const QgsSimplifyMethod &simplifyMethod() const { return mSimplifyMethod; }
725
733 QgsCoordinateReferenceSystem destinationCrs() const;
734
741 QgsCoordinateTransformContext transformContext() const;
742
765 QgsFeatureRequest &setDestinationCrs( const QgsCoordinateReferenceSystem &crs, const QgsCoordinateTransformContext &context );
766
774#ifndef SIP_RUN
775 QgsFeatureRequest &setTransformErrorCallback( const std::function< void( const QgsFeature & )> &callback );
776#else
777 QgsFeatureRequest &setTransformErrorCallback( SIP_PYCALLABLE / AllowNone / );
778 % MethodCode
779 Py_BEGIN_ALLOW_THREADS
780
781 sipCpp->setTransformErrorCallback( [a0]( const QgsFeature &arg )
782 {
783 SIP_BLOCK_THREADS
784 Py_XDECREF( sipCallMethod( NULL, a0, "D", &arg, sipType_QgsFeature, NULL ) );
785 SIP_UNBLOCK_THREADS
786 } );
787
788 sipRes = sipCpp;
789
790 Py_END_ALLOW_THREADS
791 % End
792#endif
793
801 std::function< void( const QgsFeature & ) > transformErrorCallback() const { return mTransformErrorCallback; } SIP_SKIP
802
803
812 bool acceptFeature( const QgsFeature &feature );
813
822 Q_DECL_DEPRECATED int connectionTimeout() const SIP_DEPRECATED;
823
832 Q_DECL_DEPRECATED QgsFeatureRequest &setConnectionTimeout( int connectionTimeout ) SIP_DEPRECATED;
833
843 int timeout() const;
844
854 QgsFeatureRequest &setTimeout( int timeout );
855
869 bool requestMayBeNested() const;
870
884 QgsFeatureRequest &setRequestMayBeNested( bool requestMayBeNested );
885
897 void setFeedback( QgsFeedback *feedback );
898
907 QgsFeedback *feedback() const;
908
909 protected:
910
914 Qgis::FeatureRequestFilterType mFilter = Qgis::FeatureRequestFilterType::NoFilter;
915
921 Qgis::SpatialFilterType mSpatialFilter = Qgis::SpatialFilterType::NoFilter;
922
926 QgsRectangle mFilterRect;
927
931 QgsGeometry mReferenceGeometry;
932
936 std::shared_ptr< QgsGeometryEngine > mReferenceGeometryEngine;
937
941 double mDistanceWithin = 0;
942
943 QgsFeatureId mFilterFid = -1;
944 QgsFeatureIds mFilterFids;
945 std::unique_ptr< QgsExpression > mFilterExpression;
946 QgsExpressionContext mExpressionContext;
947 Qgis::FeatureRequestFlags mFlags;
949 QgsSimplifyMethod mSimplifyMethod;
950 long long mLimit = -1;
951 OrderBy mOrderBy;
952 Qgis::InvalidGeometryCheck mInvalidGeometryFilter = Qgis::InvalidGeometryCheck::NoCheck;
953 std::function< void( const QgsFeature & ) > mInvalidGeometryCallback;
954 std::function< void( const QgsFeature & ) > mTransformErrorCallback;
957 int mTimeout = -1;
958 int mRequestMayBeNested = false;
959 QgsFeedback *mFeedback = nullptr;
960};
961
962
965
971{
972 public:
974
975
976 // IMPORTANT -- do NOT remove the /TransferBack/ annotation here -- while it looks completely wrong, it's
977 // required for Python data providers to work correctly! Argh!
978
985
986 // IMPORTANT -- do NOT remove the /TransferBack/ annotation here -- while it looks completely wrong, it's
987 // required for Python data providers to work correctly! Argh!
988
989 protected:
990 void iteratorOpened( QgsAbstractFeatureIterator *it );
991 void iteratorClosed( QgsAbstractFeatureIterator *it );
992
993 QSet< QgsAbstractFeatureIterator * > mActiveIterators;
994
995 template<typename> friend class QgsAbstractFeatureIteratorFromSource;
996};
997
998#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:1856
@ NoFilter
No filter is applied.
SpatialFilterType
Feature request spatial filter types.
Definition qgis.h:1885
QFlags< FeatureRequestFlag > FeatureRequestFlags
Flags for controlling feature requests.
Definition qgis.h:1845
InvalidGeometryCheck
Methods for handling of features with invalid geometries.
Definition qgis.h:1872
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:58
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:46
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
bool operator==(const QgsFeatureIterator &fi1, const QgsFeatureIterator &fi2)
bool operator!=(const QgsFeatureIterator &fi1, const QgsFeatureIterator &fi2)
QList< int > QgsAttributeList
Definition qgsfield.h:27
const QgsCoordinateReferenceSystem & crs