Value Relation implementation

Values in the Value Relation widgets can be translated now - means changed.
So the setting-change is made to get translated values over another layer.

Author: signedav

src/core/qgsproject.cpp

@@ -479,10 +479,18 @@ void QgsProject::registerTranslatableObjects( QgsTranslationContext *translation
       const QgsFields fields = vlayer->fields();
       for ( const QgsField &field : fields )
       {
+        QString fieldName;
         if ( field.alias().isEmpty() )
-          translationContext->registerTranslation( QStringLiteral( "project:layers:%1:fieldaliases" ).arg( vlayer->id() ), field.name() );
+          fieldName = field.name();
         else
-          translationContext->registerTranslation( QStringLiteral( "project:layers:%1:fieldaliases" ).arg( vlayer->id() ), field.alias() );
+          fieldName = field.alias();
+
+        translationContext->registerTranslation( QStringLiteral( "project:layers:%1:fieldaliases" ).arg( vlayer->id() ), fieldName );
+
+        if ( field.editorWidgetSetup().type() == QStringLiteral( "ValueRelation" ) )
+        {
+          translationContext->registerTranslation( QStringLiteral( "project:layers:%1:fields:%2:valuerelationvalue" ).arg( vlayer->id(), field.name() ), field.editorWidgetSetup().config().value( QStringLiteral( "Value" ) ).toString() );
+        }
       }
 
       //register formcontainers

src/core/qgsvectorlayer.cpp

@@ -2035,6 +2035,10 @@ bool QgsVectorLayer::readSymbology( const QDomNode &layerNode, QString &errorMes
     const QDomElement cfgElem = fieldConfigElement.elementsByTagName( QStringLiteral( "config" ) ).at( 0 ).toElement();
     const QDomElement optionsElem = cfgElem.childNodes().at( 0 ).toElement();
     QVariantMap optionsMap = QgsXmlUtils::readVariant( optionsElem ).toMap();
+    if ( widgetType == QStringLiteral( "ValueRelation" ) )
+    {
+      optionsMap[ QStringLiteral( "Value" ) ] = context.projectTranslator()->translate( QStringLiteral( "project:layers:%1:fields:%2:valuerelationvalue" ).arg( layerNode.namedItem( QStringLiteral( "id" ) ).toElement().text(), fieldName ), optionsMap[ QStringLiteral( "Value" ) ].toString() );
+    }
     QgsEditorWidgetSetup setup = QgsEditorWidgetSetup( widgetType, optionsMap );
     mFieldWidgetSetups[fieldName] = setup;
   }

tests/src/core/testqgstranslateproject.cpp

@@ -71,7 +71,7 @@ void TestQgsTranslateProject::cleanupTestCase()
 
   //delete created ts file
   QString tsFileName( TEST_DATA_DIR );
-  tsFileName = tsFileName + "/project_translation/points_translation_de.ts";
+  tsFileName = tsFileName + "/project_translation/points_translation.ts";
   QFile tsFile( tsFileName );
   tsFile.remove();
 }
@@ -99,7 +99,7 @@ void TestQgsTranslateProject::createTsFile()
 
   //check if ts file is created
   QString tsFileName( TEST_DATA_DIR );
-  tsFileName = tsFileName + "/project_translation/points_translation_de.ts";
+  tsFileName = tsFileName + "/project_translation/points_translation.ts";
   QFile tsFile( tsFileName );
   QVERIFY( tsFile.exists() );