QgsValueMapSearchW inherits QgsSearchW

and not QgsDefaultSearchW anymore
fixes expression creation

src/gui/editorwidgets/qgsvaluemapsearchwidgetwrapper.cpp

@@ -23,7 +23,7 @@
 #include <QSizePolicy>
 
 QgsValueMapSearchWidgetWrapper::QgsValueMapSearchWidgetWrapper( QgsVectorLayer* vl, int fieldIdx, QWidget* parent )
-    : QgsDefaultSearchWidgetWrapper( vl, fieldIdx, parent ),
+    : QgsSearchWidgetWrapper( vl, fieldIdx, parent ),
     mComboBox( NULL )
 {
 }
@@ -33,17 +33,30 @@ QWidget* QgsValueMapSearchWidgetWrapper::createWidget( QWidget* parent )
   return new QComboBox( parent );
 }
 
-void QgsValueMapSearchWidgetWrapper::comboBoxIndexChanged( int )
+void QgsValueMapSearchWidgetWrapper::comboBoxIndexChanged( int idx )
 {
   if ( mComboBox )
-    setExpression( mComboBox->itemData( mComboBox->currentIndex() ).toString() );
+  {
+    setExpression( mComboBox->itemData( idx ).toString() );
+    emit expressionChanged( mExpression );
+  }
 }
 
 bool QgsValueMapSearchWidgetWrapper::applyDirectly()
 {
   return true;
 }
 
+QString QgsValueMapSearchWidgetWrapper::expression()
+{
+  return mExpression;
+}
+
+bool QgsValueMapSearchWidgetWrapper::valid()
+{
+  return true;
+}
+
 void QgsValueMapSearchWidgetWrapper::initWidget( QWidget* editor )
 {
   mComboBox = qobject_cast<QComboBox*>( editor );
@@ -63,3 +76,15 @@ void QgsValueMapSearchWidgetWrapper::initWidget( QWidget* editor )
   }
 }
 
+void QgsValueMapSearchWidgetWrapper::setExpression( QString exp )
+{
+  QString fieldName = layer()->fields().at( mFieldIdx ).name();
+  QString str;
+
+  str = QString( "%1 = '%2'" )
+        .arg( QgsExpression::quotedColumnRef( fieldName ),
+              exp.replace( '\'', "''" ) );
+
+  mExpression = str;
+}
+

src/gui/editorwidgets/qgsvaluemapsearchwidgetwrapper.h

@@ -16,24 +16,33 @@
 #ifndef QGSVALUEMAPSEARCHWIDGETWRAPPER_H
 #define QGSVALUEMAPSEARCHWIDGETWRAPPER_H
 
-#include "qgsdefaultsearchwidgetwrapper.h"
+#include "qgssearchwidgetwrapper.h"
 #include <QComboBox>
 
+/**
+ * Wraps a value map search widget. This widget will offer a combobox with values from another layer
+ * referenced by a foreign key (a constraint may be set but is not required on data level).
+ * It will be used as a search widget and produces expression to look for in the layer.
+ */
 
-
-class GUI_EXPORT QgsValueMapSearchWidgetWrapper : public QgsDefaultSearchWidgetWrapper
+class GUI_EXPORT QgsValueMapSearchWidgetWrapper : public QgsSearchWidgetWrapper
 {
     Q_OBJECT
   public:
     explicit QgsValueMapSearchWidgetWrapper( QgsVectorLayer* vl, int fieldIdx, QWidget* parent = 0 );
     bool applyDirectly() override;
+    QString expression() override;
+    bool valid() override;
 
   protected:
     QWidget* createWidget( QWidget* parent ) override;
     void initWidget( QWidget* editor ) override;
 
+  protected slots:
+    void setExpression( QString exp ) override;
+
   private slots:
-    void comboBoxIndexChanged( int );
+    void comboBoxIndexChanged( int idx );
 
   private:
     QComboBox * mComboBox;