[atribute form] Add parent context when editing a child feature throu…

…gh the relation editor widget
qgis · Apr 28, 2024 · 0c108b3 · 0c108b3
1 parent 5739343
commit 0c108b3
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Showing 3 changed files with 55 additions and 1 deletion.
diff --git a/src/gui/attributeformconfig/qgsattributetypedialog.cpp b/src/gui/attributeformconfig/qgsattributetypedialog.cpp
@@ -346,6 +346,7 @@ QgsExpressionContext QgsAttributeTypeDialog::createExpressionContext() const
       << QgsExpressionContextUtils::projectScope( QgsProject::instance() )
       << QgsExpressionContextUtils::layerScope( mLayer )
       << QgsExpressionContextUtils::formScope( )
+      << QgsExpressionContextUtils::parentFormScope( QgsFeature() )
       << QgsExpressionContextUtils::mapToolCaptureScope( QList<QgsPointLocator::Match>() );
 
   return context;

diff --git a/src/gui/qgsattributeform.cpp b/src/gui/qgsattributeform.cpp
@@ -354,7 +354,13 @@ bool QgsAttributeForm::saveEdits( QString *error )
     // An add dialog should perform an action by default
     // and not only if attributes have "changed"
     if ( mMode == QgsAttributeEditorContext::AddFeatureMode || mMode == QgsAttributeEditorContext::FixAttributeMode )
+    {
       doUpdate = true;
+    }
+    else
+    {
+      updateDefaultValues();
+    }
 
     QgsAttributes src = mFeature.attributes();
     QgsAttributes dst = mFeature.attributes();
@@ -462,7 +468,7 @@ bool QgsAttributeForm::saveEdits( QString *error )
           n++;
         }
 
-        success = mLayer->changeAttributeValues( mFeature.id(), newValues, oldValues );
+        success = mLayer->changeAttributeValues( mFeature.id(), newValues, oldValues, true );
 
         if ( success && n > 0 )
         {
@@ -530,6 +536,44 @@ QgsFeature QgsAttributeForm::getUpdatedFeature() const
   return updatedFeature;
 }
 
+void QgsAttributeForm::updateDefaultValues()
+{
+  if ( !mFeature.isValid()
+       && mMode != QgsAttributeEditorContext::AddFeatureMode )
+    return;
+
+  // create updated Feature
+  QgsFeature updatedFeature = getUpdatedFeature();
+
+  // go through depending fields and update the fields with defaultexpression
+  for ( QgsWidgetWrapper *ww : std::as_const( mWidgets ) )
+  {
+    QgsEditorWidgetWrapper *eww = qobject_cast<QgsEditorWidgetWrapper *>( ww );
+    if ( eww )
+    {
+      // Update only on form opening (except when applyOnUpdate is activated)
+      if ( mValuesInitialized && !eww->field().defaultValueDefinition().applyOnUpdate() )
+        continue;
+
+      // Update only when mMode is AddFeatureMode (except when applyOnUpdate is activated)
+      if ( mMode != QgsAttributeEditorContext::AddFeatureMode && !eww->field().defaultValueDefinition().applyOnUpdate() )
+      {
+        continue;
+      }
+
+      //do not update when this widget is already updating (avoid recursions)
+      if ( mAlreadyUpdatedFields.contains( eww->fieldIdx() ) )
+        continue;
+
+      QgsExpressionContext context = createExpressionContext( updatedFeature );
+
+      const QVariant value = mLayer->defaultValue( eww->fieldIdx(), updatedFeature, &context );
+      eww->setValue( value );
+      mCurrentFormFeature.setAttribute( eww->field().name(), value );
+    }
+  }
+}
+
 void QgsAttributeForm::updateValuesDependencies( const int originIdx )
 {
   updateValuesDependenciesDefaultValues( originIdx );
@@ -570,6 +614,7 @@ void QgsAttributeForm::updateValuesDependenciesDefaultValues( const int originId
         continue;
 
       QgsExpressionContext context = createExpressionContext( updatedFeature );
+
       const QVariant value = mLayer->defaultValue( eww->fieldIdx(), updatedFeature, &context );
       eww->setValue( value );
       mCurrentFormFeature.setAttribute( eww->field().name(), value );
@@ -984,7 +1029,13 @@ QgsExpressionContext QgsAttributeForm::createExpressionContext( const QgsFeature
   context.appendScopes( QgsExpressionContextUtils::globalProjectLayerScopes( mLayer ) );
   context.appendScope( QgsExpressionContextUtils::formScope( feature, mContext.attributeFormModeString() ) );
   if ( mExtraContextScope )
+  {
     context.appendScope( new QgsExpressionContextScope( *mExtraContextScope.get() ) );
+  }
+  if ( mContext.parentFormFeature().isValid() )
+  {
+    context.appendScope( QgsExpressionContextUtils::parentFormScope( mContext.parentFormFeature() ) );
+  }
   context.setFeature( feature );
   return context;
 }

diff --git a/src/gui/qgsattributeform.h b/src/gui/qgsattributeform.h
@@ -424,6 +424,8 @@ class GUI_EXPORT QgsAttributeForm : public QWidget
     void updateValuesDependenciesVirtualFields( const int originIdx );
     void updateRelatedLayerFields();
 
+    void updateDefaultValues();
+
     void clearMultiEditMessages();
     void pushSelectedFeaturesMessage();
     void runSearchSelect( Qgis::SelectBehavior behavior );