Renamed to represent_attributes

qgis · Dec 13, 2021 · f0a337c · f0a337c
1 parent c9c5896
commit f0a337c
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Showing 3 changed files with 68 additions and 18 deletions.
diff --git a/resources/function_help/json/represent_attributes b/resources/function_help/json/represent_attributes
@@ -0,0 +1,14 @@
+{
+  "name": "represent_attributes",
+  "type": "function",
+  "groups": ["Record and Attributes"],
+  "description": "Returns a map with the attribute names as keys and the configured representation values as values. The representation value for the attributes depends on the configured widget type for each attribute. Often, this is useful for 'Value Map' widgets.",
+  "arguments": [
+    {"arg":"feature", "description": "The feature containing the attributes to be represented. (Optional)" },
+    {"arg":"layer", "description": "The vector layer the feature belongs to. (Optional)"}
+  ],
+  "examples": [
+    { "expression":"represent_attributes()", "returns":"The representation values for the current feature"},
+    { "expression":"represent_attributes(feature, layer)", "returns":"The representation values for the specified feature and layer"}
+  ]
+}
diff --git a/src/core/expression/qgsexpressionfunction.cpp b/src/core/expression/qgsexpressionfunction.cpp
@@ -1727,47 +1727,78 @@ static QVariant fcnAttributes( const QVariantList &values, const QgsExpressionCo
   return result;
 }
 
-static QVariant fcnFormattedAttributes( const QVariantList &values, const QgsExpressionContext *context, QgsExpression *parent, const QgsExpressionNodeFunction * )
+static QVariant fcnRepresentAttributes( const QVariantList &values, const QgsExpressionContext *context, QgsExpression *parent, const QgsExpressionNodeFunction * )
 {
-  QgsVectorLayer *vl = nullptr;
+  QgsVectorLayer *layer = nullptr;
   QgsFeature feature;
-  if ( values.size() == 0 || values.at( 0 ).isNull() )
+  if ( ( values.size() == 0 || values.at( 0 ).isNull() ) && context )
   {
     feature = context->feature();
     // first step - find current layer
-    vl = QgsExpressionUtils::getVectorLayer( context->variable( QStringLiteral( "layer" ) ), parent );
+    layer = QgsExpressionUtils::getVectorLayer( context->variable( QStringLiteral( "layer" ) ), parent );
   }
   else if ( values.size() == 2 && ! values.at( 1 ).isNull() )
   {
     feature = QgsExpressionUtils::getFeature( values.at( 0 ), parent );
-    vl = QgsExpressionUtils::getVectorLayer( values.at( 1 ), parent );
+    layer = QgsExpressionUtils::getVectorLayer( values.at( 1 ), parent );
   }
   else
   {
     parent->setEvalErrorString( QObject::tr( "Layer is not set" ) );
     return QVariant();
   }
 
-  if ( !vl )
+  if ( !layer )
   {
-    parent->setEvalErrorString( QObject::tr( "Cannot use formatted attributes function in this context" ) );
+    parent->setEvalErrorString( QObject::tr( "Cannot use represent attributes function in this context: layer coould not be resolved." ) );
     return QVariant();
   }
 
   const QgsFields fields = feature.fields();
   QVariantMap result;
-  for ( int idx = 0; idx < fields.count(); ++idx )
+  for ( int fieldIndex = 0; fieldIndex < fields.count(); ++fieldIndex )
   {
-    QVariant attributeVal { feature.attribute( idx ) };
-    const QgsEditorWidgetSetup setup = vl->editorWidgetSetup( idx );
-    QgsFieldFormatter *fieldFormatter = QgsApplication::fieldFormatterRegistry()->fieldFormatter( setup.type() );
-    QString value( fieldFormatter->representValue( vl, idx, setup.config(), QVariant(), attributeVal ) );
-
-    if ( setup.config().value( QStringLiteral( "AllowMulti" ) ).toBool() && value.startsWith( QLatin1Char( '{' ) ) && value.endsWith( QLatin1Char( '}' ) ) )
+    const QString fieldName { fields.at( fieldIndex ).name() };
+    QVariant attributeVal { feature.attribute( fieldIndex ) };
+    const QString cacheValueKey = QStringLiteral( "repvalfcnval:%1:%2:%3" ).arg( layer ? layer->id() : QStringLiteral( "[None]" ), fieldName, attributeVal.toString() );
+    if ( context && context->hasCachedValue( cacheValueKey ) )
     {
-      value = value.mid( 1, value.size() - 2 );
+      result.insert( fieldName, context->cachedValue( cacheValueKey ) );
+    }
+    else
+    {
+      const QgsEditorWidgetSetup setup = layer->editorWidgetSetup( fieldIndex );
+      QgsFieldFormatter *fieldFormatter = QgsApplication::fieldFormatterRegistry()->fieldFormatter( setup.type() );
+      QVariant cache;
+      if ( context )
+      {
+        const QString cacheKey = QStringLiteral( "repvalfcn:%1:%2" ).arg( layer ? layer->id() : QStringLiteral( "[None]" ), fieldName );
+
+        if ( !context->hasCachedValue( cacheKey ) )
+        {
+          cache = fieldFormatter->createCache( layer, fieldIndex, setup.config() );
+          context->setCachedValue( cacheKey, cache );
+        }
+        else
+        {
+          cache = context->cachedValue( cacheKey );
+        }
+      }
+      QString value( fieldFormatter->representValue( layer, fieldIndex, setup.config(), cache, attributeVal ) );
+
+      if ( setup.config().value( QStringLiteral( "AllowMulti" ), false ).toBool() && value.startsWith( QLatin1Char( '{' ) ) && value.endsWith( QLatin1Char( '}' ) ) )
+      {
+        value = value.mid( 1, value.size() - 2 );
+      }
+
+      result.insert( fields.at( fieldIndex ).name(), value );
+
+      if ( context )
+      {
+        context->setCachedValue( cacheValueKey, value );
+      }
+
     }
-    result.insert( fields.at( idx ).name(), value );
   }
   return result;
 }
@@ -7708,8 +7739,8 @@ const QList<QgsExpressionFunction *> &QgsExpression::Functions()
         fcnAttributes, QStringLiteral( "Record and Attributes" ), QString(), false, QSet<QString>() << QgsFeatureRequest::ALL_ATTRIBUTES );
     attributesFunc->setIsStatic( false );
     functions << attributesFunc;
-    QgsStaticExpressionFunction *formattedAttributesFunc = new QgsStaticExpressionFunction( QStringLiteral( "formatted_attributes" ), QgsExpressionFunction::ParameterList() << QgsExpressionFunction::Parameter( QStringLiteral( "feature" ), true ) << QgsExpressionFunction::Parameter( QStringLiteral( "layer" ), true ),
-        fcnFormattedAttributes, QStringLiteral( "Record and Attributes" ), QString(), false, QSet<QString>() << QgsFeatureRequest::ALL_ATTRIBUTES );
+    QgsStaticExpressionFunction *formattedAttributesFunc = new QgsStaticExpressionFunction( QStringLiteral( "represent_attributes" ), QgsExpressionFunction::ParameterList() << QgsExpressionFunction::Parameter( QStringLiteral( "feature" ), true ) << QgsExpressionFunction::Parameter( QStringLiteral( "layer" ), true ),
+        fcnRepresentAttributes, QStringLiteral( "Record and Attributes" ), QString(), false, QSet<QString>() << QgsFeatureRequest::ALL_ATTRIBUTES );
     formattedAttributesFunc->setIsStatic( false );
     functions << formattedAttributesFunc;
 

diff --git a/tests/src/core/testqgsexpression.cpp b/tests/src/core/testqgsexpression.cpp
@@ -516,6 +516,11 @@ class TestQgsExpression: public QObject
       QCOMPARE( exp.dump(), dump );
     }
 
+    void  represent_attributes()
+    {
+
+    };
+
     void represent_value()
     {
       QVariantMap config;