QGIS API Documentation 3.27.0-Master (0a97e3138f)
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 enum Flag
87 {
88 NoFlags = 0,
89 NoGeometry = 1,
90 SubsetOfAttributes = 2,
91 ExactIntersect = 4,
92 IgnoreStaticNodesDuringExpressionCompilation = 8,
93 EmbeddedSymbols = 16,
94 };
95 Q_DECLARE_FLAGS( Flags, Flag )
96
97
101 {
105 FilterFids
106 };
107
110 {
111 GeometryNoCheck = 0,
112 GeometrySkipInvalid = 1,
113 GeometryAbortOnInvalid = 2,
114 };
115
139 class CORE_EXPORT OrderByClause
140 {
141 public:
142
151 OrderByClause( const QString &expression, bool ascending = true );
152
160 OrderByClause( const QString &expression, bool ascending, bool nullsfirst );
161
170 OrderByClause( const QgsExpression &expression, bool ascending = true );
171
179 OrderByClause( const QgsExpression &expression, bool ascending, bool nullsfirst );
180
185 QgsExpression expression() const;
186
194 bool prepare( QgsExpressionContext *context );
195
200 bool ascending() const;
201
205 void setAscending( bool ascending );
206
211 bool nullsFirst() const;
212
216 void setNullsFirst( bool nullsFirst );
217
221 QString dump() const;
222
223 // friend inline int qHash(const OrderByClause &a) { return qHash(a.mExpression.expression()) ^ qHash(a.mAscending) ^ qHash( a.mNullsFirst); }
224
225 bool operator==( const OrderByClause &v ) const
226 {
227 return mExpression == v.mExpression &&
228 mAscending == v.mAscending &&
229 mNullsFirst == v.mNullsFirst;
230 }
231
232 bool operator!=( const OrderByClause &v ) const
233 {
234 return !( v == *this );
235 }
236
237 private:
238 QgsExpression mExpression;
239 bool mAscending;
240 bool mNullsFirst;
241 };
242
243
251 class OrderBy : public QList<QgsFeatureRequest::OrderByClause>
252 {
253 public:
254
258 CORE_EXPORT OrderBy();
259
263 CORE_EXPORT OrderBy( const QList<QgsFeatureRequest::OrderByClause> &other );
264
271 QList<QgsFeatureRequest::OrderByClause> CORE_EXPORT list() const;
272
276 void CORE_EXPORT save( QDomElement &elem ) const;
277
281 void CORE_EXPORT load( const QDomElement &elem );
282
287 QSet<QString> CORE_EXPORT usedAttributes() const;
288
293 QSet<int> CORE_EXPORT usedAttributeIndices( const QgsFields &fields ) const;
294
298 QString CORE_EXPORT dump() const;
299 };
300
304 static const QString ALL_ATTRIBUTES;
305
309 explicit QgsFeatureRequest( QgsFeatureId fid );
311 explicit QgsFeatureRequest( const QgsFeatureIds &fids );
312
320 explicit QgsFeatureRequest( const QgsRectangle &rectangle );
321
323 explicit QgsFeatureRequest( const QgsExpression &expr, const QgsExpressionContext &context = QgsExpressionContext() );
327 QgsFeatureRequest &operator=( const QgsFeatureRequest &rh );
328
330
342 FilterType filterType() const { return mFilter; }
343
356 Qgis::SpatialFilterType spatialFilterType() const { return mSpatialFilter; }
357
370 QgsFeatureRequest &setFilterRect( const QgsRectangle &rectangle );
371
387 QgsRectangle filterRect() const;
388
404 QgsFeatureRequest &setDistanceWithin( const QgsGeometry &geometry, double distance );
405
420 QgsGeometry referenceGeometry() const { return mReferenceGeometry; }
421
430 std::shared_ptr< QgsGeometryEngine > referenceGeometryEngine() const SIP_SKIP { return mReferenceGeometryEngine; }
431
443 double distanceWithin() const { return mDistanceWithin; }
444
453 QgsFeatureRequest &setFilterFid( QgsFeatureId fid );
454
461 QgsFeatureId filterFid() const { return mFilterFid; }
462
471 QgsFeatureRequest &setFilterFids( const QgsFeatureIds &fids );
472
479 const QgsFeatureIds &filterFids() const { return mFilterFids; }
480
488 QgsFeatureRequest &setInvalidGeometryCheck( InvalidGeometryCheck check );
489
495 InvalidGeometryCheck invalidGeometryCheck() const { return mInvalidGeometryFilter; }
496
504#ifndef SIP_RUN
505 QgsFeatureRequest &setInvalidGeometryCallback( const std::function< void( const QgsFeature & )> &callback );
506#else
507 QgsFeatureRequest &setInvalidGeometryCallback( SIP_PYCALLABLE / AllowNone / );
508 % MethodCode
509 Py_BEGIN_ALLOW_THREADS
510
511 sipCpp->setInvalidGeometryCallback( [a0]( const QgsFeature &arg )
512 {
513 SIP_BLOCK_THREADS
514 Py_XDECREF( sipCallMethod( NULL, a0, "D", &arg, sipType_QgsFeature, NULL ) );
515 SIP_UNBLOCK_THREADS
516 } );
517
518 sipRes = sipCpp;
519
520 Py_END_ALLOW_THREADS
521 % End
522#endif
523
531 std::function< void( const QgsFeature & ) > invalidGeometryCallback() const { return mInvalidGeometryCallback; } SIP_SKIP
532
542 QgsFeatureRequest &setFilterExpression( const QString &expression );
543
549 QgsExpression *filterExpression() const { return mFilterExpression.get(); }
550
560 QgsFeatureRequest &combineFilterExpression( const QString &expression );
561
568 QgsExpressionContext *expressionContext() { return &mExpressionContext; }
569
576 QgsFeatureRequest &setExpressionContext( const QgsExpressionContext &context );
577
589 QgsFeatureRequest &disableFilter() { mFilter = FilterNone; mFilterExpression.reset(); return *this; }
590
602 QgsFeatureRequest &addOrderBy( const QString &expression, bool ascending = true );
603
613 QgsFeatureRequest &addOrderBy( const QString &expression, bool ascending, bool nullsfirst );
614
620 OrderBy orderBy() const;
621
627 QgsFeatureRequest &setOrderBy( const OrderBy &orderBy );
628
635 QgsFeatureRequest &setLimit( long long limit );
636
642#ifndef SIP_RUN
643 long long limit() const { return mLimit; }
644#else
645 long long limit() const;
646#endif
647
653 QgsFeatureRequest &setFlags( QgsFeatureRequest::Flags flags );
654
660 Flags flags() const { return mFlags; }
661
678 QgsFeatureRequest &setSubsetOfAttributes( const QgsAttributeList &attrs );
679
695 QgsFeatureRequest &setNoAttributes();
696
710 QgsAttributeList subsetOfAttributes() const { return mAttrs; }
711
723 QgsFeatureRequest &setSubsetOfAttributes( const QStringList &attrNames, const QgsFields &fields );
724
736 QgsFeatureRequest &setSubsetOfAttributes( const QSet<QString> &attrNames, const QgsFields &fields );
737
744 QgsFeatureRequest &setSimplifyMethod( const QgsSimplifyMethod &simplifyMethod );
745
752 const QgsSimplifyMethod &simplifyMethod() const { return mSimplifyMethod; }
753
762 QgsCoordinateReferenceSystem destinationCrs() const;
763
771 QgsCoordinateTransformContext transformContext() const;
772
796 QgsFeatureRequest &setDestinationCrs( const QgsCoordinateReferenceSystem &crs, const QgsCoordinateTransformContext &context );
797
806#ifndef SIP_RUN
807 QgsFeatureRequest &setTransformErrorCallback( const std::function< void( const QgsFeature & )> &callback );
808#else
809 QgsFeatureRequest &setTransformErrorCallback( SIP_PYCALLABLE / AllowNone / );
810 % MethodCode
811 Py_BEGIN_ALLOW_THREADS
812
813 sipCpp->setTransformErrorCallback( [a0]( const QgsFeature &arg )
814 {
815 SIP_BLOCK_THREADS
816 Py_XDECREF( sipCallMethod( NULL, a0, "D", &arg, sipType_QgsFeature, NULL ) );
817 SIP_UNBLOCK_THREADS
818 } );
819
820 sipRes = sipCpp;
821
822 Py_END_ALLOW_THREADS
823 % End
824#endif
825
834 std::function< void( const QgsFeature & ) > transformErrorCallback() const { return mTransformErrorCallback; } SIP_SKIP
835
836
846 bool acceptFeature( const QgsFeature &feature );
847
857 Q_DECL_DEPRECATED int connectionTimeout() const SIP_DEPRECATED;
858
868 Q_DECL_DEPRECATED QgsFeatureRequest &setConnectionTimeout( int connectionTimeout ) SIP_DEPRECATED;
869
879 int timeout() const;
880
890 QgsFeatureRequest &setTimeout( int timeout );
891
905 bool requestMayBeNested() const;
906
920 QgsFeatureRequest &setRequestMayBeNested( bool requestMayBeNested );
921
933 void setFeedback( QgsFeedback *feedback );
934
943 QgsFeedback *feedback() const;
944
945 protected:
946
950 FilterType mFilter = FilterNone;
951
957 Qgis::SpatialFilterType mSpatialFilter = Qgis::SpatialFilterType::NoFilter;
958
962 QgsRectangle mFilterRect;
963
967 QgsGeometry mReferenceGeometry;
968
972 std::shared_ptr< QgsGeometryEngine > mReferenceGeometryEngine;
973
977 double mDistanceWithin = 0;
978
979 QgsFeatureId mFilterFid = -1;
980 QgsFeatureIds mFilterFids;
981 std::unique_ptr< QgsExpression > mFilterExpression;
982 QgsExpressionContext mExpressionContext;
983 Flags mFlags = Flags();
985 QgsSimplifyMethod mSimplifyMethod;
986 long long mLimit = -1;
987 OrderBy mOrderBy;
988 InvalidGeometryCheck mInvalidGeometryFilter = GeometryNoCheck;
989 std::function< void( const QgsFeature & ) > mInvalidGeometryCallback;
990 std::function< void( const QgsFeature & ) > mTransformErrorCallback;
993 int mTimeout = -1;
994 int mRequestMayBeNested = false;
995 QgsFeedback *mFeedback = nullptr;
996};
997
999
1000
1001class QgsFeatureIterator;
1003
1010{
1011 public:
1012 virtual ~QgsAbstractFeatureSource();
1013
1014
1015 // IMPORTANT -- do NOT remove the /TransferBack/ annotation here -- while it looks completely wrong, it's
1016 // required for Python data providers to work correctly! Argh!
1017
1024
1025 // IMPORTANT -- do NOT remove the /TransferBack/ annotation here -- while it looks completely wrong, it's
1026 // required for Python data providers to work correctly! Argh!
1027
1028 protected:
1029 void iteratorOpened( QgsAbstractFeatureIterator *it );
1030 void iteratorClosed( QgsAbstractFeatureIterator *it );
1031
1032 QSet< QgsAbstractFeatureIterator * > mActiveIterators;
1033
1034 template<typename> friend class QgsAbstractFeatureIteratorFromSource;
1035};
1036
1037#endif // QGSFEATUREREQUEST_H
The Qgis class provides global constants for use throughout the application.
Definition: qgis.h:72
SpatialFilterType
Feature request spatial filter types.
Definition: qgis.h:1026
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).
InvalidGeometryCheck
Handling of features with invalid geometries.
InvalidGeometryCheck invalidGeometryCheck() const
Returns the invalid geometry checking behavior.
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()...
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.
Flags 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.
FilterType filterType() const
Returns the attribute/ID filter type which is currently set on this request.
FilterType
Types of filters.
@ FilterFid
Filter using feature ID.
@ FilterNone
No filter is applied.
@ FilterExpression
Filter using expression.
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:45
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.
Definition: qgsgeometry.h:125
A rectangle specified with double values.
Definition: qgsrectangle.h:42
This class contains information about how to simplify geometries fetched from a QgsFeatureIterator.
std::unique_ptr< GEOSGeometry, GeosDeleter > unique_ptr
Scoped GEOS pointer.
Definition: qgsgeos.h:79
#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
Definition: qgsfeatureid.h:37
qint64 QgsFeatureId
64 bit feature ids negative numbers are used for uncommitted/newly added features
Definition: qgsfeatureid.h:28
QList< int > QgsAttributeList
Definition: qgsfield.h:26
Q_DECLARE_OPERATORS_FOR_FLAGS(QgsField::ConfigurationFlags) CORE_EXPORT QDataStream &operator<<(QDataStream &out
Writes the field to stream out. QGIS version compatibility is not guaranteed.
const QgsCoordinateReferenceSystem & crs