[attribute form] Insure that a field features multiple times in a feature form has its constraint properly reflected

python/PyQt6/gui/auto_generated/editorwidgets/core/qgseditorwidgetwrapper.sip.in

@@ -162,6 +162,16 @@ Update constraint on a feature coming from a specific layer.
                          based constraints.
 
 .. versionadded:: 3.0
+%End
+
+    void updateConstraint( QgsEditorWidgetWrapper::ConstraintResult constraintResult, const QString &constraintFailureReason );
+%Docstring
+Update constraint manually by providing the constraint result value and failure reason(s).
+
+:param constraintResult: the constraint result value
+:param constraintFailureReason: the constraint failure reason(s) (blank is the result passes)
+
+.. versionadded:: 3.36
 %End
 
     bool isValidConstraint() const;

python/gui/auto_generated/editorwidgets/core/qgseditorwidgetwrapper.sip.in

@@ -162,6 +162,16 @@ Update constraint on a feature coming from a specific layer.
                          based constraints.
 
 .. versionadded:: 3.0
+%End
+
+    void updateConstraint( QgsEditorWidgetWrapper::ConstraintResult constraintResult, const QString &constraintFailureReason );
+%Docstring
+Update constraint manually by providing the constraint result value and failure reason(s).
+
+:param constraintResult: the constraint result value
+:param constraintFailureReason: the constraint failure reason(s) (blank is the result passes)
+
+.. versionadded:: 3.36
 %End
 
     bool isValidConstraint() const;

src/gui/editorwidgets/core/qgseditorwidgetwrapper.cpp

@@ -266,6 +266,15 @@ void QgsEditorWidgetWrapper::updateConstraint( const QgsVectorLayer *layer, int
   }
 }
 
+void QgsEditorWidgetWrapper::updateConstraint( QgsEditorWidgetWrapper::ConstraintResult constraintResult, const QString &constraintFailureReason )
+{
+  mValidConstraint = constraintResult == ConstraintResultPass;
+  mIsBlockingCommit = constraintResult == ConstraintResultFailHard;
+  mConstraintFailureReason = constraintResult != ConstraintResultPass ? constraintFailureReason : QString();
+  mConstraintResult = constraintResult;
+  updateConstraintWidgetStatus();
+}
+
 bool QgsEditorWidgetWrapper::isValidConstraint() const
 {
   return mValidConstraint;

src/gui/editorwidgets/core/qgseditorwidgetwrapper.h

@@ -175,6 +175,14 @@ class GUI_EXPORT QgsEditorWidgetWrapper : public QgsWidgetWrapper
      */
     void updateConstraint( const QgsVectorLayer *layer, int index, const QgsFeature &feature, QgsFieldConstraints::ConstraintOrigin constraintOrigin = QgsFieldConstraints::ConstraintOriginNotSet );
 
+    /**
+     * Update constraint manually by providing the constraint result value and failure reason(s).
+     * \param constraintResult the constraint result value
+     * \param constraintFailureReason the constraint failure reason(s) (blank is the result passes)
+     * \since QGIS 3.36
+     */
+    void updateConstraint( QgsEditorWidgetWrapper::ConstraintResult constraintResult, const QString &constraintFailureReason );
+
     /**
      * Gets the current constraint status.
      * \returns TRUE if the constraint is valid or if there's no constraint,

src/gui/qgsattributeform.cpp

@@ -1057,6 +1057,21 @@ void QgsAttributeForm::onAttributeChanged( const QVariant &value, const QVariant
       break;
   }
 
+  // Update other widgets pointing to the same field, required to happen now to insure
+  // currentFormValuesFeature() gets the right value when processing constraints
+  const QList<QgsAttributeFormEditorWidget *> formEditorWidgets = mFormEditorWidgets.values( eww->fieldIdx() );
+  for ( QgsAttributeFormEditorWidget *formEditorWidget : formEditorWidgets )
+  {
+    if ( formEditorWidget->editorWidget() == eww )
+      continue;
+
+    // formEditorWidget and eww points to the same field, so block signals
+    // as there is no need to handle valueChanged again for each duplicate
+    formEditorWidget->editorWidget()->blockSignals( true );
+    formEditorWidget->editorWidget()->setValue( value );
+    formEditorWidget->editorWidget()->blockSignals( false );
+  }
+
   updateConstraints( eww );
 
   // Update dependent fields (only if form is not initializing)
@@ -1072,20 +1087,6 @@ void QgsAttributeForm::onAttributeChanged( const QVariant &value, const QVariant
   updateLabels();
   updateEditableState();
 
-  // Update other widgets pointing to the same field
-  const QList<QgsAttributeFormEditorWidget *> formEditorWidgets = mFormEditorWidgets.values( eww->fieldIdx() );
-  for ( QgsAttributeFormEditorWidget *formEditorWidget : formEditorWidgets )
-  {
-    if ( formEditorWidget->editorWidget() == eww )
-      continue;
-
-    // formEditorWidget and eww points to the same field, so block signals
-    // as there is no need to handle valueChanged again for each duplicate
-    formEditorWidget->editorWidget()->blockSignals( true );
-    formEditorWidget->editorWidget()->setValue( value );
-    formEditorWidget->editorWidget()->blockSignals( false );
-  }
-
   if ( !signalEmitted )
   {
     Q_NOWARN_DEPRECATED_PUSH
@@ -1435,7 +1436,13 @@ void QgsAttributeForm::onConstraintStatusChanged( const QString &constraint,
   const QList<QgsAttributeFormEditorWidget *> formEditorWidgets = mFormEditorWidgets.values( eww->fieldIdx() );
 
   for ( QgsAttributeFormEditorWidget *formEditorWidget : formEditorWidgets )
+  {
     formEditorWidget->setConstraintStatus( constraint, description, err, result );
+    if ( formEditorWidget->editorWidget() != eww )
+    {
+      formEditorWidget->editorWidget()->updateConstraint( result, err );
+    }
+  }
 }
 
 QList<QgsEditorWidgetWrapper *> QgsAttributeForm::constraintDependencies( QgsEditorWidgetWrapper *w )

tests/src/gui/testqgsattributeform.cpp

@@ -61,6 +61,7 @@ class TestQgsAttributeForm : public QObject
     void testSameFieldSync();
     void testZeroDoubles();
     void testMinimumWidth();
+    void testFieldConstraintDuplicateField();
 
   private:
     QLabel *constraintsLabel( QgsAttributeForm *form, QgsEditorWidgetWrapper *ww )
@@ -1211,5 +1212,40 @@ void TestQgsAttributeForm::testMinimumWidth()
 
 }
 
+void TestQgsAttributeForm::testFieldConstraintDuplicateField()
+{
+  // make a temporary vector layer
+  const QString def = QStringLiteral( "Point?field=col0:integer" );
+  QgsVectorLayer *layer = new QgsVectorLayer( def, QStringLiteral( "test" ), QStringLiteral( "memory" ) );
+  layer->setEditorWidgetSetup( 0, QgsEditorWidgetSetup( QStringLiteral( "Range" ), QVariantMap() ) );
+
+  // add same field twice so they get synced
+  QgsEditFormConfig editFormConfig = layer->editFormConfig();
+  editFormConfig.clearTabs();
+  editFormConfig.invisibleRootContainer()->addChildElement( new QgsAttributeEditorField( "col0", 0, editFormConfig.invisibleRootContainer() ) );
+  editFormConfig.invisibleRootContainer()->addChildElement( new QgsAttributeEditorField( "col0", 0, editFormConfig.invisibleRootContainer() ) );
+  editFormConfig.setLayout( Qgis::AttributeFormLayout::DragAndDrop );
+  layer->setEditFormConfig( editFormConfig );
+
+  // add a feature to the vector layer
+  QgsFeature ft( layer->dataProvider()->fields(), 1 );
+  ft.setAttribute( QStringLiteral( "col0" ), 1 );
+
+  // set a not null constraint
+  layer->setConstraintExpression( 0, QStringLiteral( "col0 > 10" ) );
+
+  // build a form for this feature
+  QgsAttributeForm form( layer );
+  form.setFeature( ft );
+
+  const QList<QgsAttributeFormEditorWidget *> formEditorWidgets = form.mFormEditorWidgets.values( 0 );
+  QCOMPARE( formEditorWidgets[0]->editorWidget()->constraintResult(), QgsEditorWidgetWrapper::ConstraintResultFailHard );
+  QCOMPARE( formEditorWidgets[1]->editorWidget()->constraintResult(), QgsEditorWidgetWrapper::ConstraintResultFailHard );
+
+  formEditorWidgets[0]->editorWidget()->setValues( 20, QVariantList() );
+  QCOMPARE( formEditorWidgets[0]->editorWidget()->constraintResult(), QgsEditorWidgetWrapper::ConstraintResultPass );
+  QCOMPARE( formEditorWidgets[1]->editorWidget()->constraintResult(), QgsEditorWidgetWrapper::ConstraintResultPass );
+}
+
 QGSTEST_MAIN( TestQgsAttributeForm )
 #include "testqgsattributeform.moc"