Fix #51543 and make big forms more fluid

domi4484 · github-actions[bot] · commit 398d38df15fd · 2023-03-07T16:21:46.000Z
diff --git a/src/gui/qgsattributeform.cpp b/src/gui/qgsattributeform.cpp
@@ -522,8 +522,6 @@ QgsFeature QgsAttributeForm::getUpdatedFeature() const
 
 void QgsAttributeForm::updateValuesDependencies( const int originIdx )
 {
-  updateFieldDependencies();
-
   updateValuesDependenciesDefaultValues( originIdx );
   updateValuesDependenciesVirtualFields( originIdx );
 }
@@ -547,7 +545,11 @@ void QgsAttributeForm::updateValuesDependenciesDefaultValues( const int originId
     QgsEditorWidgetWrapper *eww = qobject_cast<QgsEditorWidgetWrapper *>( ww );
     if ( eww )
     {
-      //do not update when when mMode is not AddFeatureMode and it's not applyOnUpdate
+      // 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;
@@ -906,6 +908,23 @@ void QgsAttributeForm::resetValues()
   {
     ww->setFeature( mFeature );
   }
+
+  // Prepare value dependencies
+  updateFieldDependencies();
+
+  // Update dependent fields
+  for ( QgsWidgetWrapper *ww : constMWidgets )
+  {
+    QgsEditorWidgetWrapper *eww = qobject_cast<QgsEditorWidgetWrapper *>( ww );
+    if ( !eww )
+      continue;
+
+    // Append field index here, so it's not updated recursively
+    mAlreadyUpdatedFields.append( eww->fieldIdx() );
+    updateValuesDependencies( eww->fieldIdx() );
+    mAlreadyUpdatedFields.removeAll( eww->fieldIdx() );
+  }
+
   mValuesInitialized = true;
   mDirty = false;
 }
diff --git a/tests/src/python/test_qgsattributeform.py b/tests/src/python/test_qgsattributeform.py
@@ -178,6 +178,38 @@ def test_on_update(self):
         form.changeAttribute('age', 7)
         self.assertEqual(form.currentFormFeature()['numbers'], [1, 7])
 
+    def test_default_value_alway_updated(self):
+        """Test that default values are not updated on every edit operation
+        when containing an 'attribute' expression"""
+
+        layer = QgsVectorLayer("Point?field=age:int&field=number:int", "vl", "memory")
+
+        layer.setEditorWidgetSetup(0, QgsEditorWidgetSetup('Range', {}))
+
+        # set default value for numbers to attribute("age"), it will depend on the field age and should not update
+        layer.setDefaultValueDefinition(1, QgsDefaultValue("attribute(@feature, 'age')", False))
+        layer.setEditorWidgetSetup(1, QgsEditorWidgetSetup('Range', {}))
+
+        layer.startEditing()
+
+        feature = QgsFeature(layer.fields())
+        feature.setAttribute('age', 15)
+
+        form = QgsAttributeForm(layer)
+        form.setMode(QgsAttributeEditorContext.AddFeatureMode)
+        form.setFeature(feature)
+
+        QGISAPP.processEvents()
+
+        self.assertEqual(form.currentFormFeature()['age'], 15)
+        self.assertEqual(form.currentFormFeature()['number'], 15)
+        # return
+        form.changeAttribute('number', 12)
+        form.changeAttribute('age', 1)
+        self.assertEqual(form.currentFormFeature()['number'], 12)
+        form.changeAttribute('age', 7)
+        self.assertEqual(form.currentFormFeature()['number'], 12)
+
 
 if __name__ == '__main__':
     unittest.main()
