[API] add QgsVectorLayer::updateFeature()

jef-n · jef-n · commit f39a19c12b13 · 2011-10-07T16:15:51.000Z
diff --git a/python/core/qgsvectorlayer.sip b/python/core/qgsvectorlayer.sip
@@ -272,10 +272,18 @@ public:
   bool featureAtId(int featureId, QgsFeature& f, bool fetchGeometries = true, bool fetchAttributes = true);
 
   /** Adds a feature
+      @param f feature to add
       @param alsoUpdateExtent    If True, will also go to the effort of e.g. updating the extents.
       @return                    True in case of success and False in case of error
    */
   bool addFeature(QgsFeature& f, bool alsoUpdateExtent = TRUE);
+
+  /** Update an existing feature
+      @param f feature to update
+      @return                    True in case of success and False in case of error
+      @note added in 1.8
+   */
+  bool updateFeature(QgsFeature& f );
   
   
   /** Insert a new vertex before the given vertex number,
diff --git a/src/core/qgsvectorlayer.cpp b/src/core/qgsvectorlayer.cpp
@@ -1947,6 +1947,42 @@ bool QgsVectorLayer::addFeature( QgsFeature& f, bool alsoUpdateExtent )
   return true;
 }
 
+bool QgsVectorLayer::updateFeature( QgsFeature &f )
+{
+  QgsFeature current;
+  if ( !featureAtId( f.id(), current, f.geometry(), !f.attributeMap().isEmpty() ) )
+  {
+    QgsDebugMsg( QString( "feature %1 could not be retrieved" ).arg( f.id() ) );
+    return false;
+  }
+
+  if ( f.geometry() && current.geometry() && f.geometry() != current.geometry() && !f.geometry()->isGeosEqual( *current.geometry() ) )
+  {
+    if ( !changeGeometry( f.id(), f.geometry() ) )
+    {
+      QgsDebugMsg( QString( "geometry of feature %1 could not be changed." ).arg( f.id() ) );
+      return false;
+    }
+  }
+
+  const QgsAttributeMap &fa = f.attributeMap();
+  const QgsAttributeMap &ca = current.attributeMap();
+
+  foreach( int attr, fa.keys() )
+  {
+    if ( fa.contains( attr ) && ca.contains( attr ) && fa[attr] != ca[attr] )
+    {
+      if ( !changeAttributeValue( f.id(), attr, fa[attr] ) )
+      {
+        QgsDebugMsg( QString( "attribute %1 of feature %2 could not be changed." ).arg( attr ).arg( f.id() ) );
+        return false;
+      }
+    }
+  }
+
+  return true;
+}
+
 
 bool QgsVectorLayer::insertVertex( double x, double y, QgsFeatureId atFeatureId, int beforeVertex )
 {
diff --git a/src/core/qgsvectorlayer.h b/src/core/qgsvectorlayer.h
@@ -351,6 +351,12 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer
      */
     bool addFeature( QgsFeature& f, bool alsoUpdateExtent = true );
 
+    /** Updates an existing feature
+        @param f feature to update
+        @return                    True in case of success and False in case of error
+        @note added in 1.8
+     */
+    bool updateFeature( QgsFeature &f );
 
     /** Insert a new vertex before the given vertex number,
      *  in the given ring, item (first number is index 0), and feature
