QGIS API Documentation  3.21.0-Master (5b68dc587e)
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 
38 {
39  public:
41  {
43  ValueRelationItem( const QVariant &key, const QString &value, const QString &description = QString() )
44  : key( key )
45  , value( value )
46  , description( description )
47  {}
48 
50  ValueRelationItem() = default;
51 
52  QVariant key;
53  QString value;
54  QString description;
55  };
56 
57  typedef QVector < QgsValueRelationFieldFormatter::ValueRelationItem > ValueRelationCache;
58 
63 
64  QString id() const override;
65  QString representValue( QgsVectorLayer *layer, int fieldIndex, const QVariantMap &config, const QVariant &cache, const QVariant &value ) const override;
66 
67  QVariant sortValue( QgsVectorLayer *layer, int fieldIndex, const QVariantMap &config, const QVariant &cache, const QVariant &value ) const override;
68 
69  QVariant createCache( QgsVectorLayer *layer, int fieldIndex, const QVariantMap &config ) const override;
70 
75  static QStringList valueToStringList( const QVariant &value );
76 
88  static QgsValueRelationFieldFormatter::ValueRelationCache createCache( const QVariantMap &config, const QgsFeature &formFeature = QgsFeature(), const QgsFeature &parentFormFeature = QgsFeature() );
89 
98  static bool expressionRequiresFormScope( const QString &expression );
99 
107  static QSet<QString> expressionFormAttributes( const QString &expression );
108 
116  static QSet<QString> expressionFormVariables( const QString &expression );
117 
126  static bool expressionRequiresParentFormScope( const QString &expression );
127 
135  static QSet<QString> expressionParentFormAttributes( const QString &expression );
136 
144  static QSet<QString> expressionParentFormVariables( const QString &expression );
145 
146 
154  static bool expressionIsUsable( const QString &expression, const QgsFeature &feature, const QgsFeature &parentFeature = QgsFeature() );
155 
160  static QgsVectorLayer *resolveLayer( const QVariantMap &config, const QgsProject *project );
161 
162  QList<QgsVectorLayerRef> layerDependencies( const QVariantMap &config ) const override SIP_SKIP;
163 
164  QVariantList availableValues( const QVariantMap &config, int countLimit, const QgsFieldFormatterContext &context ) const override;
165 };
166 
168 
169 #endif // QGSVALUERELATIONFIELDKIT_H
The feature class encapsulates a single feature including its unique ID, geometry and a list of field...
Definition: qgsfeature.h:56
A context for field formatter containing information like the project.
A field formatter helps to handle and display values for a field.
virtual QVariant createCache(QgsVectorLayer *layer, int fieldIndex, const QVariantMap &config) const
Create a cache for a given field.
virtual QString id() const =0
Returns a unique id for this field formatter.
virtual QVariantList availableValues(const QVariantMap &config, int countLimit, const QgsFieldFormatterContext &context) const
Returns a list of the values that would be possible to select with this widget type On a RelationRefe...
virtual QVariant sortValue(QgsVectorLayer *layer, int fieldIndex, const QVariantMap &config, const QVariant &cache, const QVariant &value) const
If the default sort order should be overwritten for this widget, you can transform the value in here.
virtual QList< QgsVectorLayerRef > layerDependencies(const QVariantMap &config) const SIP_SKIP
Returns a list of weak layer references to other layers required by this formatter for the given conf...
virtual QString representValue(QgsVectorLayer *layer, int fieldIndex, const QVariantMap &config, const QVariant &cache, const QVariant &value) const
Create a pretty String representation of the value.
Encapsulates a QGIS project, including sets of map layers and their styles, layouts,...
Definition: qgsproject.h:101
Field formatter for a value relation field.
QVector< QgsValueRelationFieldFormatter::ValueRelationItem > ValueRelationCache
Represents a vector layer which manages a vector based data sets.
#define SIP_SKIP
Definition: qgis_sip.h:126
Q_DECLARE_METATYPE(QgsMeshTimeSettings)
ValueRelationItem()=default
Constructor for ValueRelationItem.
ValueRelationItem(const QVariant &key, const QString &value, const QString &description=QString())
Constructor for ValueRelationItem.