Fix relation reference widget when 'Chain Filters' is activated. Fixes …

…#16903
qgis · Aug 17, 2017 · 40ad860 · 40ad860
1 parent 987f1ac
commit 40ad860
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Showing 2 changed files with 93 additions and 32 deletions.
diff --git a/src/gui/editorwidgets/qgsrelationreferencewidget.cpp b/src/gui/editorwidgets/qgsrelationreferencewidget.cpp
@@ -785,13 +785,41 @@ void QgsRelationReferenceWidget::filterChanged()
 {
   QVariant nullValue = QSettings().value( "qgis/nullValue", "NULL" );
 
-  QStringList filters;
+  QMap<QString, QString> filters;
   QgsAttributeList attrs;
 
   QComboBox* scb = qobject_cast<QComboBox*>( sender() );
 
   Q_ASSERT( scb );
 
+  QgsFeature f;
+  QgsFeatureIds featureIds;
+  QString filterExpression;
+
+  // comboboxes have to be disabled before building filters
+  if ( mChainFilters )
+    disableChainedComboBoxes( scb );
+
+  // build filters
+  Q_FOREACH ( QComboBox *cb, mFilterComboBoxes )
+  {
+    if ( cb->currentIndex() != 0 )
+    {
+      const QString fieldName = cb->property( "Field" ).toString();
+
+      if ( cb->currentText() == nullValue.toString() )
+      {
+        filters[fieldName] = QString( "\"%1\" IS NULL" ).arg( fieldName );
+      }
+      else
+      {
+        filters[fieldName] = QgsExpression::createFieldEqualityExpression( fieldName, cb->currentText() );
+      }
+      attrs << mReferencedLayer->fieldNameIndex( fieldName );
+    }
+  }
+
+  bool filtered = false;
   if ( mChainFilters )
   {
     QComboBox* ccb = nullptr;
@@ -805,13 +833,11 @@ void QgsRelationReferenceWidget::filterChanged()
         continue;
       }
 
-      if ( ccb->currentIndex() == 0 )
-      {
-        cb->setCurrentIndex( 0 );
-        cb->setEnabled( false );
-      }
-      else
+      if ( ccb->currentIndex() != 0 )
       {
+        const QString fieldName = cb->property( "Field" ).toString();
+        filtered = true;
+
         cb->blockSignals( true );
         cb->clear();
         cb->addItem( cb->property( "FieldAlias" ).toString() );
@@ -821,8 +847,30 @@ void QgsRelationReferenceWidget::filterChanged()
         QStringList texts;
         Q_FOREACH ( const QString& txt, mFilterCache[ccb->property( "Field" ).toString()][ccb->currentText()] )
         {
-          texts << txt;
+          QMap<QString, QString> filtersAttrs = filters;
+          filtersAttrs[fieldName] = QgsExpression::createFieldEqualityExpression( fieldName, txt );
+          QStringList vals = filtersAttrs.values();
+          QString expression = vals.join( QString( " AND " ) );
+
+          QgsAttributeList subset = attrs;
+          subset << mReferencedLayer->fieldNameIndex( fieldName );
+
+          QgsFeatureIterator it( mMasterModel->layerCache()->getFeatures( QgsFeatureRequest().setFilterExpression( expression ).setSubsetOfAttributes( subset ) ) );
+
+          bool found = false;
+          while ( it.nextFeature( f ) )
+          {
+            if ( !featureIds.contains( f.id() ) )
+              featureIds << f.id();
+
+            found = true;
+          }
+
+          // item is only provided if at least 1 feature exists
+          if ( found )
+            texts << txt;
         }
+
         texts.sort();
         cb->addItems( texts );
 
@@ -834,34 +882,21 @@ void QgsRelationReferenceWidget::filterChanged()
     }
   }
 
-  Q_FOREACH ( QComboBox* cb, mFilterComboBoxes )
+  if ( !mChainFilters || ( mChainFilters && !filtered ) )
   {
-    if ( cb->currentIndex() != 0 )
-    {
-      const QString fieldName = cb->property( "Field" ).toString();
+    QStringList vals = filters.values();
+    filterExpression = vals.join( QString( " AND " ) );
 
-      if ( cb->currentText() == nullValue.toString() )
-      {
-        filters << QString( "\"%1\" IS NULL" ).arg( fieldName );
-      }
-      else
-      {
-        filters << QgsExpression::createFieldEqualityExpression( fieldName, cb->currentText() );
-      }
-      attrs << mReferencedLayer->fieldNameIndex( fieldName );
-    }
-  }
-
-  QString filterExpression = filters.join( " AND " );
-
-  QgsFeatureIterator it( mMasterModel->layerCache()->getFeatures( QgsFeatureRequest().setFilterExpression( filterExpression ).setSubsetOfAttributes( attrs ) ) );
+    QgsFeatureRequest req = QgsFeatureRequest().setSubsetOfAttributes( attrs );
+    if ( !filterExpression.isEmpty() )
+      req.setFilterExpression( filterExpression );
 
-  QgsFeature f;
-  QgsFeatureIds featureIds;
+    QgsFeatureIterator it( mMasterModel->layerCache()->getFeatures( req ) );
 
-  while ( it.nextFeature( f ) )
-  {
-    featureIds << f.id();
+    while ( it.nextFeature( f ) )
+    {
+      featureIds << f.id();
+    }
   }
 
   mFilterModel->setFilteredFeatures( featureIds );
@@ -896,3 +931,28 @@ void QgsRelationReferenceWidget::updateAddEntryButton()
   mAddEntryButton->setVisible( mAllowAddFeatures );
   mAddEntryButton->setEnabled( mReferencedLayer && mReferencedLayer->isEditable() );
 }
+
+void QgsRelationReferenceWidget::disableChainedComboBoxes( const QComboBox *scb )
+{
+  QComboBox *ccb = nullptr;
+  Q_FOREACH ( QComboBox *cb, mFilterComboBoxes )
+  {
+    if ( !ccb )
+    {
+      if ( cb == scb )
+      {
+        ccb = cb;
+      }
+
+      continue;
+    }
+
+    if ( ccb->currentIndex() == 0 )
+    {
+      cb->setCurrentIndex( 0 );
+      cb->setEnabled( false );
+    }
+    else
+      ccb = cb;
+  }
+}
diff --git a/src/gui/editorwidgets/qgsrelationreferencewidget.h b/src/gui/editorwidgets/qgsrelationreferencewidget.h
@@ -162,6 +162,7 @@ class GUI_EXPORT QgsRelationReferenceWidget : public QWidget
   private:
     void highlightFeature( QgsFeature f = QgsFeature(), CanvasExtent canvasExtent = Fixed );
     void updateAttributeEditorFrame( const QgsFeature& feature );
+    void disableChainedComboBoxes( const QComboBox *scb );
 
     // initialized
     QgsAttributeEditorContext mEditorContext;