=== modified file 'dhis-2/dhis-api/src/main/java/org/hisp/dhis/indicator/IndicatorGroup.java'
--- dhis-2/dhis-api/src/main/java/org/hisp/dhis/indicator/IndicatorGroup.java	2011-05-05 21:14:56 +0000
+++ dhis-2/dhis-api/src/main/java/org/hisp/dhis/indicator/IndicatorGroup.java	2011-05-30 15:27:38 +0000
@@ -60,6 +60,38 @@
     {
         this.name = name;
     }
+
+    // -------------------------------------------------------------------------
+    // Logic
+    // -------------------------------------------------------------------------
+
+    public void addIndicator( Indicator indicator )
+    {
+        members.add( indicator );
+        indicator.getGroups().remove( this );
+    }
+    
+    public void removeIndicator( Indicator indicator )
+    {
+        members.remove( indicator );
+        indicator.getGroups().remove( this );
+    }
+    
+    public void updateIndicators( Set<Indicator> updates )
+    {
+        for ( Indicator indicator : new HashSet<Indicator>( members ) )
+        {
+            if ( !updates.contains( indicator ) )
+            {
+                removeIndicator( indicator );
+            }
+        }
+        
+        for ( Indicator indicator : updates )
+        {
+            addIndicator( indicator );
+        }
+    }
     
     // -------------------------------------------------------------------------
     // hashCode and equals

=== modified file 'dhis-2/dhis-web/dhis-web-maintenance/dhis-web-maintenance-datadictionary/src/main/java/org/hisp/dhis/dd/action/dataelementgroup/UpdateDataElementGroupAction.java'
--- dhis-2/dhis-web/dhis-web-maintenance/dhis-web-maintenance-datadictionary/src/main/java/org/hisp/dhis/dd/action/dataelementgroup/UpdateDataElementGroupAction.java	2011-05-30 14:56:19 +0000
+++ dhis-2/dhis-web/dhis-web-maintenance/dhis-web-maintenance-datadictionary/src/main/java/org/hisp/dhis/dd/action/dataelementgroup/UpdateDataElementGroupAction.java	2011-05-30 15:27:38 +0000
@@ -104,18 +104,15 @@
             dataElementGroup.setName( name );
         }
 
-        if ( !groupMembers.isEmpty() )
+        Set<DataElement> members = new HashSet<DataElement>();
+
+        for ( String id : groupMembers )
         {
-            Set<DataElement> members = new HashSet<DataElement>();
-
-            for ( String id : groupMembers )
-            {
-                members.add( dataElementService.getDataElement( Integer.parseInt( id ) ) );
-            }
-
-            dataElementGroup.updateDataElements( members );
+            members.add( dataElementService.getDataElement( Integer.parseInt( id ) ) );
         }
 
+        dataElementGroup.updateDataElements( members );
+
         dataElementService.updateDataElementGroup( dataElementGroup );
 
         return SUCCESS;

=== modified file 'dhis-2/dhis-web/dhis-web-maintenance/dhis-web-maintenance-datadictionary/src/main/java/org/hisp/dhis/dd/action/indicatorgroup/AddIndicatorGroupAction.java'
--- dhis-2/dhis-web/dhis-web-maintenance/dhis-web-maintenance-datadictionary/src/main/java/org/hisp/dhis/dd/action/indicatorgroup/AddIndicatorGroupAction.java	2011-05-05 21:15:45 +0000
+++ dhis-2/dhis-web/dhis-web-maintenance/dhis-web-maintenance-datadictionary/src/main/java/org/hisp/dhis/dd/action/indicatorgroup/AddIndicatorGroupAction.java	2011-05-30 15:27:38 +0000
@@ -27,11 +27,9 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-import java.util.Collection;
 import java.util.HashSet;
 import java.util.Set;
 
-import org.hisp.dhis.indicator.Indicator;
 import org.hisp.dhis.indicator.IndicatorGroup;
 import org.hisp.dhis.indicator.IndicatorService;
 
@@ -66,9 +64,9 @@
         this.name = name;
     }
 
-    private Collection<String> groupMembers;
+    private Set<String> groupMembers = new HashSet<String>();
 
-    public void setGroupMembers( Collection<String> groupMembers )
+    public void setGroupMembers( Set<String> groupMembers )
     {
         this.groupMembers = groupMembers;
     }
@@ -88,18 +86,11 @@
     {
         indicatorGroup = new IndicatorGroup( name );
         
-        if ( groupMembers != null )
+        for ( String id : groupMembers )
         {
-            Set<Indicator> members = new HashSet<Indicator>();
-
-            for ( String id : groupMembers )
-            {
-                members.add( indicatorService.getIndicator( Integer.parseInt( id ) ) );
-            }
-
-            indicatorGroup.setMembers( members );            
+            indicatorGroup.addIndicator( indicatorService.getIndicator( Integer.parseInt( id ) ) );
         }
-        
+
         indicatorService.addIndicatorGroup( indicatorGroup );        
 
         return SUCCESS;

=== modified file 'dhis-2/dhis-web/dhis-web-maintenance/dhis-web-maintenance-datadictionary/src/main/java/org/hisp/dhis/dd/action/indicatorgroup/UpdateIndicatorGroupAction.java'
--- dhis-2/dhis-web/dhis-web-maintenance/dhis-web-maintenance-datadictionary/src/main/java/org/hisp/dhis/dd/action/indicatorgroup/UpdateIndicatorGroupAction.java	2011-05-05 21:15:45 +0000
+++ dhis-2/dhis-web/dhis-web-maintenance/dhis-web-maintenance-datadictionary/src/main/java/org/hisp/dhis/dd/action/indicatorgroup/UpdateIndicatorGroupAction.java	2011-05-30 15:27:38 +0000
@@ -27,7 +27,6 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-import java.util.Collection;
 import java.util.HashSet;
 import java.util.Set;
 
@@ -74,9 +73,9 @@
         this.name = name;
     }
 
-    private Collection<String> groupMembers;
+    private Set<String> groupMembers = new HashSet<String>();
 
-    public void setGroupMembers( Collection<String> groupMembers )
+    public void setGroupMembers( Set<String> groupMembers )
     {
         this.groupMembers = groupMembers;
     }
@@ -101,21 +100,14 @@
             indicatorGroup.setName( name );
         }
 
-        if ( groupMembers != null )
-        {
-            Set<Indicator> members = new HashSet<Indicator>();
-
-            for ( String memberId : groupMembers )
-            {
-                members.add( indicatorService.getIndicator( Integer.parseInt( memberId ) ) );
-            }
-
-            indicatorGroup.setMembers( members );
-        }
-        else
-        {
-            indicatorGroup.getMembers().clear();
-        }
+        Set<Indicator> members = new HashSet<Indicator>();
+
+        for ( String memberId : groupMembers )
+        {
+            members.add( indicatorService.getIndicator( Integer.parseInt( memberId ) ) );
+        }
+
+        indicatorGroup.updateIndicators( members );
 
         indicatorService.updateIndicatorGroup( indicatorGroup );