[bugfix] Fixes relation widget reference when filter value contains a…

… quote #16399
qgis · Jul 10, 2017 · a20b0dc · a20b0dc
1 parent e6dc103
commit a20b0dc
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Showing 5 changed files with 34 additions and 35 deletions.
diff --git a/python/core/qgsexpression.sip b/python/core/qgsexpression.sip
@@ -1008,6 +1008,15 @@ class QgsExpression
      */
     static QString formatPreviewString( const QVariant& value );
 
+    /** Create an expression allowing to evaluate if a field is equal to a
+     *  value. The value may be null.
+     * @param fieldName the name of the field
+     * @param value the value of the field
+     * @returns the expression to evaluate field equality
+     * @since QGIS 2.18
+     */
+    static QString createFieldEqualityExpression( const QString &fieldName, const QVariant &value );
+
   protected:
     void initGeomCalculator();
 };
diff --git a/src/core/qgsexpression.cpp b/src/core/qgsexpression.cpp
@@ -5324,6 +5324,18 @@ QVariant QgsExpression::StaticFunction::func( const QVariantList &values, const
   Q_NOWARN_DEPRECATED_POP
 }
 
+QString QgsExpression::createFieldEqualityExpression( const QString &fieldName, const QVariant &value )
+{
+  QString expr;
+
+  if ( value.isNull() )
+    expr = QString( "%1 IS NULL" ).arg( quotedColumnRef( fieldName ) );
+  else
+    expr = QString( "%1 = %2" ).arg( quotedColumnRef( fieldName ), quotedValue( value ) );
+
+  return expr;
+}
+
 const QgsExpression::Node* QgsExpression::rootNode() const
 {
   return d->mRootNode;

diff --git a/src/core/qgsexpression.h b/src/core/qgsexpression.h
@@ -1488,6 +1488,15 @@ class CORE_EXPORT QgsExpression
      */
     static QString formatPreviewString( const QVariant& value );
 
+    /** Create an expression allowing to evaluate if a field is equal to a
+     *  value. The value may be null.
+     * @param fieldName the name of the field
+     * @param value the value of the field
+     * @returns the expression to evaluate field equality
+     * @since QGIS 2.18
+     */
+    static QString createFieldEqualityExpression( const QString &fieldName, const QVariant &value );
+
   protected:
     void initGeomCalculator();
 

diff --git a/src/core/qgsrelation.cpp b/src/core/qgsrelation.cpp
@@ -167,19 +167,8 @@ QString QgsRelation::getRelatedFeaturesFilter( const QgsFeature& feature ) const
 
   Q_FOREACH ( const QgsRelation::FieldPair& fieldPair, mFieldPairs )
   {
-    int referencingIdx = referencingLayer()->fields().indexFromName( fieldPair.referencingField() );
-    QgsField referencingField = referencingLayer()->fields().at( referencingIdx );
-
-    if ( referencingField.type() == QVariant::String )
-    {
-      // Use quotes
-      conditions << QString( "\"%1\" = '%2'" ).arg( fieldPair.referencingField(), feature.attribute( fieldPair.referencedField() ).toString() );
-    }
-    else
-    {
-      // No quotes
-      conditions << QString( "\"%1\" = %2" ).arg( fieldPair.referencingField(), feature.attribute( fieldPair.referencedField() ).toString() );
-    }
+    QVariant val( feature.attribute( fieldPair.referencedField() ) );
+    conditions << QgsExpression::createFieldEqualityExpression( fieldPair.referencingField(), val );
   }
 
   return conditions.join( " AND " );
@@ -191,21 +180,8 @@ QgsFeatureRequest QgsRelation::getReferencedFeatureRequest( const QgsAttributes&
 
   Q_FOREACH ( const QgsRelation::FieldPair& fieldPair, mFieldPairs )
   {
-    int referencedIdx = referencedLayer()->fields().indexFromName( fieldPair.referencedField() );
     int referencingIdx = referencingLayer()->fields().indexFromName( fieldPair.referencingField() );
-
-    QgsField referencedField = referencedLayer()->fields().at( referencedIdx );
-
-    if ( referencedField.type() == QVariant::String )
-    {
-      // Use quotes
-      conditions << QString( "\"%1\" = '%2'" ).arg( fieldPair.referencedField(), attributes.at( referencingIdx ).toString() );
-    }
-    else
-    {
-      // No quotes
-      conditions << QString( "\"%1\" = %2" ).arg( fieldPair.referencedField(), attributes.at( referencingIdx ).toString() );
-    }
+    conditions << QgsExpression::createFieldEqualityExpression( fieldPair.referencedField(), attributes.at( referencingIdx ) );
   }
 
   QgsFeatureRequest myRequest;

diff --git a/src/gui/editorwidgets/qgsrelationreferencewidget.cpp b/src/gui/editorwidgets/qgsrelationreferencewidget.cpp
@@ -846,14 +846,7 @@ void QgsRelationReferenceWidget::filterChanged()
       }
       else
       {
-        if ( mReferencedLayer->fields().field( fieldName ).type() == QVariant::String )
-        {
-          filters << QString( "\"%1\" = '%2'" ).arg( fieldName, cb->currentText() );
-        }
-        else
-        {
-          filters << QString( "\"%1\" = %2" ).arg( fieldName, cb->currentText() );
-        }
+        filters << QgsExpression::createFieldEqualityExpression( fieldName, cb->currentText() );
       }
       attrs << mReferencedLayer->fieldNameIndex( fieldName );
     }