QGIS API Documentation  3.8.0-Zanzibar (11aff65)
qgsvaluerelationfieldformatter.h
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1 /***************************************************************************
2  qgsvaluerelationfieldformatter.h - QgsValueRelationFieldFormatter
3 
4  ---------------------
5  begin : 3.12.2016
6  copyright : (C) 2016 by Matthias Kuhn
7  email : [email protected]
8  ***************************************************************************
9  * *
10  * This program is free software; you can redistribute it and/or modify *
11  * it under the terms of the GNU General Public License as published by *
12  * the Free Software Foundation; either version 2 of the License, or *
13  * (at your option) any later version. *
14  * *
15  ***************************************************************************/
16 #ifndef QGSVALUERELATIONFIELDKIT_H
17 #define QGSVALUERELATIONFIELDKIT_H
18 
19 #include "qgis_core.h"
20 #include "qgsfieldformatter.h"
21 #include "qgsexpression.h"
22 #include "qgsexpressioncontext.h"
23 
24 #include <QVector>
25 #include <QVariant>
26 
27 
37 {
38  public:
40  {
42  ValueRelationItem( const QVariant &key, const QString &value )
43  : key( key )
44  , value( value )
45  {}
46 
48  ValueRelationItem() = default;
49 
50  QVariant key;
51  QString value;
52  };
53 
54  typedef QVector < QgsValueRelationFieldFormatter::ValueRelationItem > ValueRelationCache;
55 
60 
61  QString id() const override;
62  QString representValue( QgsVectorLayer *layer, int fieldIndex, const QVariantMap &config, const QVariant &cache, const QVariant &value ) const override;
63 
64  QVariant sortValue( QgsVectorLayer *layer, int fieldIndex, const QVariantMap &config, const QVariant &cache, const QVariant &value ) const override;
65 
66  QVariant createCache( QgsVectorLayer *layer, int fieldIndex, const QVariantMap &config ) const override;
67 
72  static QStringList valueToStringList( const QVariant &value );
73 
84  static QgsValueRelationFieldFormatter::ValueRelationCache createCache( const QVariantMap &config, const QgsFeature &formFeature = QgsFeature() );
85 
94  static bool expressionRequiresFormScope( const QString &expression );
95 
103  static QSet<QString> expressionFormAttributes( const QString &expression );
104 
112  static QSet<QString> expressionFormVariables( const QString &expression );
113 
120  static bool expressionIsUsable( const QString &expression, const QgsFeature &feature );
121 
126  static QgsVectorLayer *resolveLayer( const QVariantMap &config, const QgsProject *project );
127 
128 
129 
130 };
131 
133 
134 #endif // QGSVALUERELATIONFIELDKIT_H
The feature class encapsulates a single feature including its id, geometry and a list of field/values...
Definition: qgsfeature.h:55
QVector< QgsValueRelationFieldFormatter::ValueRelationItem > ValueRelationCache
Q_DECLARE_METATYPE(QgsMeshTimeSettings)
Reads and writes project states.
Definition: qgsproject.h:89
Field formatter for a value relation field.
A field formatter helps to handle and display values for a field.
ValueRelationItem(const QVariant &key, const QString &value)
Constructor for ValueRelationItem.
Represents a vector layer which manages a vector based data sets.