Merge pull request #33436 from signedav/relating_values

List referenced layer values in Expression Builder
qgis · Dec 20, 2019 · 2a01772 · 2a01772
2 parents d211de2 + ea912a1
commit 2a01772
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Showing 17 changed files with 362 additions and 27 deletions.
diff --git a/python/core/auto_generated/fieldformatter/qgsrelationreferencefieldformatter.sip.in b/python/core/auto_generated/fieldformatter/qgsrelationreferencefieldformatter.sip.in
@@ -40,6 +40,9 @@ Default constructor of field formatter for a relation reference field.
 
 
 
+    virtual QVariantList availableValues( const QVariantMap &config, int countLimit, const QgsFieldFormatterContext &context ) const;
+
+
 
 };
 

diff --git a/python/core/auto_generated/fieldformatter/qgsvaluemapfieldformatter.sip.in b/python/core/auto_generated/fieldformatter/qgsvaluemapfieldformatter.sip.in
@@ -46,6 +46,9 @@ Default constructor of field formatter for a value map field.
 
     virtual QVariant sortValue( QgsVectorLayer *layer, int fieldIndex, const QVariantMap &config, const QVariant &cache, const QVariant &value ) const;
 
+
+    virtual QVariantList availableValues( const QVariantMap &config, int countLimit, const QgsFieldFormatterContext &context ) const;
+
 };
 
 /************************************************************************

diff --git a/python/core/auto_generated/fieldformatter/qgsvaluerelationfieldformatter.sip.in b/python/core/auto_generated/fieldformatter/qgsvaluerelationfieldformatter.sip.in
@@ -128,6 +128,9 @@ Returns the (possibly NULL) layer from the widget's ``config`` and ``project``
 .. versionadded:: 3.8
 %End
 
+
+    virtual QVariantList availableValues( const QVariantMap &config, int countLimit, const QgsFieldFormatterContext &context ) const;
+
 };
 
 

diff --git a/python/core/auto_generated/qgsfieldformatter.sip.in b/python/core/auto_generated/qgsfieldformatter.sip.in
@@ -9,6 +9,40 @@
 
 
 
+class QgsFieldFormatterContext
+{
+%Docstring
+A context for field formatter containing information like the project
+
+.. versionadded:: 3.12
+%End
+
+%TypeHeaderCode
+#include "qgsfieldformatter.h"
+%End
+  public:
+
+    QgsFieldFormatterContext();
+%Docstring
+Constructor
+%End
+
+    QgsProject *project() const;
+%Docstring
+Returns the project used in field formatter
+
+.. seealso:: :py:func:`setProject`
+%End
+
+    void setProject( QgsProject *project );
+%Docstring
+Sets the ``project`` used in field formatter
+
+.. seealso:: :py:func:`project`
+%End
+
+};
+
 class QgsFieldFormatter
 {
 %Docstring
@@ -17,7 +51,7 @@ A field formatter helps to handle and display values for a field.
 It allows for using a shared configuration with the editor widgets
 for representation of attribute values.
 Field kits normally have one single instance which is managed by the
-QgsFieldFormatterRegistry. Custom field formatters should be registered there and
+:py:class:`QgsFieldFormatterRegistry`. Custom field formatters should be registered there and
 field formatters for use within code should normally be obtained from there.
 
 This is an abstract base class and will always need to be subclassed.
@@ -37,6 +71,13 @@ Default constructor
 
     virtual ~QgsFieldFormatter();
 
+    enum Flag
+    {
+      CanProvideAvailableValues
+    };
+    typedef QFlags<QgsFieldFormatter::Flag> Flags;
+
+
     virtual QString id() const = 0;
 %Docstring
 Returns a unique id for this field formatter.
@@ -87,6 +128,28 @@ make use of a cache if present.
 %End
 
 
+    virtual QVariantList availableValues( const QVariantMap &config, int countLimit, const QgsFieldFormatterContext &context ) const;
+%Docstring
+Returns a list of the values that would be possible to select with this widget type
+On a RelationReference that would be the parents ids or on ValueMap all the configured keys
+according to the settings in the ``config``
+
+.. versionadded:: 3.12
+%End
+
+    Flags flags() const;
+%Docstring
+Returns the flags
+
+.. versionadded:: 3.12
+%End
+
+    void setFlags( const Flags &flags );
+%Docstring
+Sets the ``flags``
+
+.. versionadded:: 3.12
+%End
 
 };
 

diff --git a/python/gui/auto_generated/qgsexpressionbuilderwidget.sip.in b/python/gui/auto_generated/qgsexpressionbuilderwidget.sip.in
@@ -323,12 +323,34 @@ with the context.
 
     void loadSampleValues();
 %Docstring
-Load sample values into the sample value area
+Load sample values into the sample value area.
+Including available values, in case the formatter can
+provide them (eg. RelationReference).
 %End
 
     void loadAllValues();
 %Docstring
-Load all unique values from the set layer into the sample area
+Load all unique values from the set layer into the sample area.
+Including all available values, in case the formatter can
+provide them (eg. RelationReference).
+%End
+
+    void loadSampleUsedValues();
+%Docstring
+Load used sample values into the sample value area.
+Only the used ones. Without available values, even if the
+formatter can provide them (eg. RelationReference).
+
+.. versionadded:: 3.12
+%End
+
+    void loadAllUsedValues();
+%Docstring
+Load all unique values from the set layer into the sample area.
+Only the used ones. Without available values, even if the
+formatter can provide them (eg. RelationReference).
+
+.. versionadded:: 3.12
 %End
 
     void autosave();

diff --git a/src/core/fieldformatter/qgsrelationreferencefieldformatter.cpp b/src/core/fieldformatter/qgsrelationreferencefieldformatter.cpp
@@ -23,6 +23,11 @@
 #include "qgsvectorlayer.h"
 #include "qgsexpressioncontextutils.h"
 
+QgsRelationReferenceFieldFormatter::QgsRelationReferenceFieldFormatter()
+{
+  setFlags( flags() | QgsFieldFormatter::CanProvideAvailableValues );
+}
+
 QString QgsRelationReferenceFieldFormatter::id() const
 {
   return QStringLiteral( "RelationReference" );
@@ -181,3 +186,18 @@ QList<QgsVectorLayerRef> QgsRelationReferenceFieldFormatter::layerDependencies(
     }};
   return result;
 }
+
+QVariantList QgsRelationReferenceFieldFormatter::availableValues( const QVariantMap &config, int countLimit, const QgsFieldFormatterContext &context ) const
+{
+  QVariantList values;
+  if ( context.project() )
+  {
+    const QgsVectorLayer *referencedLayer = context.project()->relationManager()->relation( config[QStringLiteral( "Relation" )].toString() ).referencedLayer();
+    if ( referencedLayer )
+    {
+      int fieldIndex =  context.project()->relationManager()->relation( config[QStringLiteral( "Relation" )].toString() ).referencedFields().first();
+      values = referencedLayer->uniqueValues( fieldIndex, countLimit ).toList();
+    }
+  }
+  return values;
+}
diff --git a/src/core/fieldformatter/qgsrelationreferencefieldformatter.h b/src/core/fieldformatter/qgsrelationreferencefieldformatter.h
@@ -34,7 +34,7 @@ class CORE_EXPORT QgsRelationReferenceFieldFormatter : public QgsFieldFormatter
     /**
       * Default constructor of field formatter for a relation reference field.
       */
-    QgsRelationReferenceFieldFormatter() = default;
+    QgsRelationReferenceFieldFormatter();
 
     QString id() const override;
 
@@ -46,6 +46,8 @@ class CORE_EXPORT QgsRelationReferenceFieldFormatter : public QgsFieldFormatter
 
     QList<QgsVectorLayerRef> layerDependencies( const QVariantMap &config ) const override SIP_SKIP;
 
+    QVariantList availableValues( const QVariantMap &config, int countLimit, const QgsFieldFormatterContext &context ) const override;
+
     //friend class TestQgsRelationReferenceFieldFormatter;
 
 };

diff --git a/src/core/fieldformatter/qgsvaluemapfieldformatter.cpp b/src/core/fieldformatter/qgsvaluemapfieldformatter.cpp
@@ -19,6 +19,11 @@
 
 const QString QgsValueMapFieldFormatter::NULL_VALUE = QStringLiteral( "{2839923C-8B7D-419E-B84B-CA2FE9B80EC7}" );
 
+QgsValueMapFieldFormatter::QgsValueMapFieldFormatter()
+{
+  setFlags( flags() | QgsFieldFormatter::CanProvideAvailableValues );
+}
+
 QString QgsValueMapFieldFormatter::id() const
 {
   return QStringLiteral( "ValueMap" );
@@ -62,3 +67,19 @@ QVariant QgsValueMapFieldFormatter::sortValue( QgsVectorLayer *layer, int fieldI
 {
   return representValue( layer, fieldIndex, config, cache, value );
 }
+
+QVariantList QgsValueMapFieldFormatter::availableValues( const QVariantMap &config, int countLimit, const QgsFieldFormatterContext &context ) const
+{
+  Q_UNUSED( context )
+
+  QVariantList values;
+  const QList<QVariant> valueList = config.value( QStringLiteral( "map" ) ).toList();
+  for ( const QVariant &item : valueList )
+  {
+    values.append( item.toMap().constBegin().value() );
+    if ( values.count() == countLimit )
+      break;
+  }
+
+  return values;
+}
diff --git a/src/core/fieldformatter/qgsvaluemapfieldformatter.h b/src/core/fieldformatter/qgsvaluemapfieldformatter.h
@@ -49,13 +49,15 @@ class CORE_EXPORT QgsValueMapFieldFormatter : public QgsFieldFormatter
     /**
       * Default constructor of field formatter for a value map field.
       */
-    QgsValueMapFieldFormatter() = default;
+    QgsValueMapFieldFormatter();
 
     QString id() const override;
 
     QString representValue( QgsVectorLayer *layer, int fieldIndex, const QVariantMap &config, const QVariant &cache, const QVariant &value ) const override;
 
     QVariant sortValue( QgsVectorLayer *layer, int fieldIndex, const QVariantMap &config, const QVariant &cache, const QVariant &value ) const override;
+
+    QVariantList availableValues( const QVariantMap &config, int countLimit, const QgsFieldFormatterContext &context ) const override;
 };
 
 #endif // QGSVALUEMAPFIELDKIT_H
diff --git a/src/core/fieldformatter/qgsvaluerelationfieldformatter.cpp b/src/core/fieldformatter/qgsvaluerelationfieldformatter.cpp
@@ -40,6 +40,11 @@ bool orderByValueLessThan( const QgsValueRelationFieldFormatter::ValueRelationIt
   return qgsVariantLessThan( p1.value, p2.value );
 }
 
+QgsValueRelationFieldFormatter::QgsValueRelationFieldFormatter()
+{
+  setFlags( flags() | QgsFieldFormatter::CanProvideAvailableValues );
+}
+
 QString QgsValueRelationFieldFormatter::id() const
 {
   return QStringLiteral( "ValueRelation" );
@@ -183,6 +188,22 @@ QList<QgsVectorLayerRef> QgsValueRelationFieldFormatter::layerDependencies( cons
   return result;
 }
 
+QVariantList QgsValueRelationFieldFormatter::availableValues( const QVariantMap &config, int countLimit, const QgsFieldFormatterContext &context ) const
+{
+  QVariantList values;
+
+  if ( context.project() )
+  {
+    const QgsVectorLayer *referencedLayer = qobject_cast<QgsVectorLayer *>( context.project()->mapLayer( config[QStringLiteral( "Layer" )].toString() ) );
+    if ( referencedLayer )
+    {
+      int fieldIndex = referencedLayer->fields().indexOf( config.value( QStringLiteral( "Key" ) ).toString() );
+      values = referencedLayer->uniqueValues( fieldIndex, countLimit ).toList();
+    }
+  }
+  return values;
+}
+
 QStringList QgsValueRelationFieldFormatter::valueToStringList( const QVariant &value )
 {
   QStringList checkList;

diff --git a/src/core/fieldformatter/qgsvaluerelationfieldformatter.h b/src/core/fieldformatter/qgsvaluerelationfieldformatter.h
@@ -56,7 +56,7 @@ class CORE_EXPORT QgsValueRelationFieldFormatter : public QgsFieldFormatter
     /**
      * Constructor for QgsValueRelationFieldFormatter.
      */
-    QgsValueRelationFieldFormatter() = default;
+    QgsValueRelationFieldFormatter();
 
     QString id() const override;
     QString representValue( QgsVectorLayer *layer, int fieldIndex, const QVariantMap &config, const QVariant &cache, const QVariant &value ) const override;
@@ -126,6 +126,8 @@ class CORE_EXPORT QgsValueRelationFieldFormatter : public QgsFieldFormatter
     static QgsVectorLayer *resolveLayer( const QVariantMap &config, const QgsProject *project );
 
     QList<QgsVectorLayerRef> layerDependencies( const QVariantMap &config ) const override SIP_SKIP;
+
+    QVariantList availableValues( const QVariantMap &config, int countLimit, const QgsFieldFormatterContext &context ) const override;
 };
 
 Q_DECLARE_METATYPE( QgsValueRelationFieldFormatter::ValueRelationCache )

diff --git a/src/core/qgsfieldformatter.cpp b/src/core/qgsfieldformatter.cpp
@@ -68,3 +68,17 @@ QList<QgsVectorLayerRef> QgsFieldFormatter::layerDependencies( const QVariantMap
   Q_UNUSED( config )
   return QList<QgsVectorLayerRef>();
 }
+
+QVariantList QgsFieldFormatter::availableValues( const QVariantMap &config, int countLimit, const QgsFieldFormatterContext &context ) const
+{
+  Q_UNUSED( config )
+  Q_UNUSED( countLimit )
+  Q_UNUSED( context )
+
+  return QVariantList();
+}
+
+void QgsFieldFormatter::setFlags( const Flags &flags )
+{
+  mFlags = flags;
+}