QGIS API Documentation  3.21.0-Master (909859188c)
qgsalgorithmdropfields.h
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1 /***************************************************************************
2  qgsalgorithmdropfields.h
3  ---------------------------------
4  begin : November 2020
5  copyright : (C) 2020 by Nyall Dawson
6  email : nyall dot dawson at gmail dot com
7  ***************************************************************************/
8 
9 /***************************************************************************
10  * *
11  * This program is free software; you can redistribute it and/or modify *
12  * it under the terms of the GNU General Public License as published by *
13  * the Free Software Foundation; either version 2 of the License, or *
14  * (at your option) any later version. *
15  * *
16  ***************************************************************************/
17 
18 #ifndef QGSALGORITHMDROPFIELDS_H
19 #define QGSALGORITHMDROPFIELDS_H
20 
21 #define SIP_NO_FILE
22 
23 #include "qgis_sip.h"
24 #include "qgsprocessingalgorithm.h"
25 
27 
31 class QgsDropTableFieldsAlgorithm : public QgsProcessingFeatureBasedAlgorithm
32 {
33 
34  public:
35 
36  QgsDropTableFieldsAlgorithm() = default;
37  QgsProcessingAlgorithm::Flags flags() const override;
38  QString name() const override;
39  QString displayName() const override;
40  QStringList tags() const override;
41  QString group() const override;
42  QString groupId() const override;
43  QString shortHelpString() const override;
44  QString shortDescription() const override;
45  QList<int> inputLayerTypes() const override;
46  QgsDropTableFieldsAlgorithm *createInstance() const override SIP_FACTORY;
47 
48  protected:
49 
50  void initParameters( const QVariantMap &configuration = QVariantMap() ) override;
51  QString outputName() const override;
52  QgsFields outputFields( const QgsFields &inputFields ) const override;
53  QgsProcessingFeatureSource::Flag sourceFlags() const override;
54 
55  bool prepareAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback ) override;
56  QgsFeatureList processFeature( const QgsFeature &feature, QgsProcessingContext &context, QgsProcessingFeedback *feedback ) override;
57  bool supportInPlaceEdit( const QgsMapLayer *layer ) const override;
58 
59  private:
60 
61  QStringList mFieldsToDelete;
62  mutable QList< int > mFieldIndices;
63 };
64 
65 
69 class QgsRetainTableFieldsAlgorithm : public QgsProcessingFeatureBasedAlgorithm
70 {
71 
72  public:
73 
74  QgsRetainTableFieldsAlgorithm() = default;
75  QgsProcessingAlgorithm::Flags flags() const override;
76  QString name() const override;
77  QString displayName() const override;
78  QStringList tags() const override;
79  QString group() const override;
80  QString groupId() const override;
81  QString shortHelpString() const override;
82  QString shortDescription() const override;
83  QList<int> inputLayerTypes() const override;
84  QgsRetainTableFieldsAlgorithm *createInstance() const override SIP_FACTORY;
85 
86  protected:
87 
88  void initParameters( const QVariantMap &configuration = QVariantMap() ) override;
89  QString outputName() const override;
90  QgsFields outputFields( const QgsFields &inputFields ) const override;
91  QgsProcessingFeatureSource::Flag sourceFlags() const override;
92 
93  bool prepareAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback ) override;
94  QgsFeatureList processFeature( const QgsFeature &feature, QgsProcessingContext &context, QgsProcessingFeedback *feedback ) override;
95  bool supportInPlaceEdit( const QgsMapLayer *layer ) const override;
96 
97  private:
98 
99  QStringList mFieldsToRetain;
100  mutable QList< int > mFieldIndices;
101 };
102 
103 
105 
106 #endif // QGSALGORITHMDROPFIELDS_H
The feature class encapsulates a single feature including its unique ID, geometry and a list of field...
Definition: qgsfeature.h:56
Container of fields for a vector layer.
Definition: qgsfields.h:45
Base class for all map layer types.
Definition: qgsmaplayer.h:72
virtual QString group() const
Returns the name of the group this algorithm belongs to.
virtual QString groupId() const
Returns the unique ID of the group this algorithm belongs to.
virtual QString shortHelpString() const
Returns a localised short helper string for the algorithm.
virtual QString shortDescription() const
Returns an optional translated short description of the algorithm.
virtual QString displayName() const =0
Returns the translated algorithm name, which should be used for any user-visible display of the algor...
virtual QgsProcessingAlgorithm * createInstance() const =0
Creates a new instance of the algorithm class.
virtual QStringList tags() const
Returns a list of tags which relate to the algorithm, and are used to assist users in searching for s...
virtual QString name() const =0
Returns the algorithm name, used for identifying the algorithm.
Contains information about the context in which a processing algorithm is executed.
An abstract QgsProcessingAlgorithm base class for processing algorithms which operate "feature-by-fea...
QgsProcessingAlgorithm::Flags flags() const override
Returns the flags indicating how and when the algorithm operates and should be exposed to users.
virtual QList< int > inputLayerTypes() const
Returns the valid input layer types for the source layer for this algorithm.
QgsFeatureSource subclass which proxies methods to an underlying QgsFeatureSource,...
Flag
Flags controlling how QgsProcessingFeatureSource fetches features.
Base class for providing feedback from a processing algorithm.
#define SIP_FACTORY
Definition: qgis_sip.h:76
QList< QgsFeature > QgsFeatureList
Definition: qgsfeature.h:831