[FEATURE] Allow changing vector layer data source

NathanW2 · NathanW2 · commit e249bfee9422 · 2015-05-17T19:54:35.000+10:00
diff --git a/python/core/qgsvectorlayer.sip b/python/core/qgsvectorlayer.sip
@@ -560,6 +560,8 @@ class QgsVectorLayer : QgsMapLayer
      */
     virtual long featureCount() const;
 
+    void setDataSource(QString dataSource, QString baseName, QString provider, bool loadDefaultStyleFlag = true);
+
     /**
      * Number of features rendered with specified symbol. Features must be first
      * calculated by countSymbolFeatures()
diff --git a/src/core/qgsvectorlayer.cpp b/src/core/qgsvectorlayer.cpp
@@ -151,31 +151,7 @@ QgsVectorLayer::QgsVectorLayer( QString vectorLayerPath,
   // if we're given a provider type, try to create and bind one to this layer
   if ( ! mProviderKey.isEmpty() )
   {
-    setDataProvider( mProviderKey );
-  }
-  if ( mValid )
-  {
-    // Always set crs
-    setCoordinateSystem();
-
-    // check if there is a default style / propertysheet defined
-    // for this layer and if so apply it
-    bool defaultLoadedFlag = false;
-    if ( loadDefaultStyleFlag )
-    {
-      loadDefaultStyle( defaultLoadedFlag );
-    }
-
-    // if the default style failed to load or was disabled use some very basic defaults
-    if ( !defaultLoadedFlag && hasGeometryType() )
-    {
-      // add single symbol renderer
-      setRendererV2( QgsFeatureRendererV2::defaultRenderer( geometryType() ) );
-    }
-
-    setLegend( QgsMapLayerLegend::defaultVectorLegend( this ) );
-
-    connect( QgsMapLayerRegistry::instance(), SIGNAL( layerWillBeRemoved( QString ) ), this, SLOT( checkJoinLayerRemove( QString ) ) );
+    setDataSource( vectorLayerPath, baseName, providerKey, loadDefaultStyleFlag );
   }
 
   connect( this, SIGNAL( selectionChanged( QgsFeatureIds, QgsFeatureIds, bool ) ), this, SIGNAL( selectionChanged() ) );
@@ -1380,6 +1356,40 @@ bool QgsVectorLayer::readXml( const QDomNode& layer_node )
 } // void QgsVectorLayer::readXml
 
 
+void QgsVectorLayer::setDataSource( QString dataSource, QString baseName, QString provider, bool loadDefaultStyleFlag )
+{
+  mDataSource = dataSource;
+  mLayerName = capitaliseLayerName( baseName );
+  setLayerName( mLayerName );
+  setDataProvider( provider );
+
+  if ( mValid )
+  {
+    // Always set crs
+    setCoordinateSystem();
+
+    // check if there is a default style / propertysheet defined
+    // for this layer and if so apply it
+    bool defaultLoadedFlag = false;
+    if ( loadDefaultStyleFlag )
+    {
+      loadDefaultStyle( defaultLoadedFlag );
+    }
+
+    // if the default style failed to load or was disabled use some very basic defaults
+    if ( !defaultLoadedFlag && hasGeometryType() )
+    {
+      // add single symbol renderer
+      setRendererV2( QgsFeatureRendererV2::defaultRenderer( geometryType() ) );
+    }
+
+    setLegend( QgsMapLayerLegend::defaultVectorLegend( this ) );
+
+    connect( QgsMapLayerRegistry::instance(), SIGNAL( layerWillBeRemoved( QString ) ), this, SLOT( checkJoinLayerRemove( QString ) ) );
+  }
+}
+
+
 bool QgsVectorLayer::setDataProvider( QString const & provider )
 {
   // XXX should I check for and possibly delete any pre-existing providers?
diff --git a/src/core/qgsvectorlayer.h b/src/core/qgsvectorlayer.h
@@ -930,6 +930,11 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer
      */
     long featureCount( QgsSymbolV2* symbol );
 
+    /**
+     * Update the data source of the layer
+     */
+    void setDataSource( QString dataSource, QString baseName, QString provider , bool loadDefaultStyleFlag = false );
+
     /**
      * Count features for symbols. Feature counts may be get by featureCount( QgsSymbolV2*).
      * @param showProgress show progress dialog
@@ -1721,6 +1726,7 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer
      */
     void writeCustomSymbology( QDomElement& element, QDomDocument& doc, QString& errorMessage ) const;
 
+
   private slots:
     void onRelationsLoaded();
     void onJoinedFieldsChanged();
@@ -1737,6 +1743,7 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer
     /** vector layers are not copyable */
     QgsVectorLayer & operator=( QgsVectorLayer const & rhs );
 
+
     /** bind layer to a specific data provider
        @param provider should be "postgres", "ogr", or ??
        @todo XXX should this return bool?  Throw exceptions?
