Addition of tidyup code for when clf:classified aspect is removed. Also added notes on what's to do if this ever becomes a core service.

git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/modules/recordsmanagement/BRANCHES/classified_renditions@111768 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

rm-server/source/java/org/alfresco/module/org_alfresco_module_rm/model/clf/aspect/ClassifiedAspect.java

@@ -56,6 +56,7 @@ import java.util.Map;
 )
 public class ClassifiedAspect extends BaseBehaviourBean implements NodeServicePolicies.OnUpdatePropertiesPolicy,
                                                                    NodeServicePolicies.OnAddAspectPolicy,
+                                                                   NodeServicePolicies.OnRemoveAspectPolicy,
                                                                    ClassifiedContentModel
 {
     private ClassificationSchemeService classificationSchemeService;
@@ -123,7 +124,7 @@ public class ClassifiedAspect extends BaseBehaviourBean implements NodeServicePo
     }
 
     /**
-     * Behaviour associated with updating the classified aspect properties.
+     * Behaviour associated with adding the classified aspect.
      * <p>
      * Validates the consistency of the properties.
      */
@@ -158,6 +159,37 @@ public class ClassifiedAspect extends BaseBehaviourBean implements NodeServicePo
         }, AuthenticationUtil.getSystemUserName());
     }
 
+    /**
+     * Behaviour associated with removing the classified aspect.
+     * <p>
+     * Validates the consistency of the properties.
+     */
+    @Override
+    @Behaviour
+    (
+        kind = BehaviourKind.CLASS,
+        notificationFrequency = NotificationFrequency.FIRST_EVENT
+    )
+    public void onRemoveAspect(final NodeRef classifiedNode, final QName aspectTypeQName)
+    {
+        AuthenticationUtil.runAs(new RunAsWork<Void>()
+        {
+            public Void doWork()
+            {
+                // If this node has any renditions, we should remove the metadata link
+                final List<ChildAssociationRef> renditions = renditionService.getRenditions(classifiedNode);
+                for (ChildAssociationRef chAssRef : renditions)
+                {
+                    // In RM, renditions are only attached to one metadata referent - the source node.
+                    // Therefore it is safe to (and we must) remove the aspect from the rendition node.
+                    nodeService.removeAspect(chAssRef.getChildRef(), ASPECT_CLASSIFIED_RENDITION);
+                }
+
+                return null;
+            }
+        }, AuthenticationUtil.getSystemUserName());
+    }
+
     /**
      * Check the consistency of the classification properties and throw an exception if they are invalid.
      *

rm-server/source/java/org/alfresco/module/org_alfresco_module_rm/referredmetadata/ReferralAdminServiceImpl.java

@@ -37,6 +37,35 @@ import java.util.Set;
  */
 public class ReferralAdminServiceImpl implements ReferralAdminService
 {
+    // Author's implementation note
+    // ----------------------------
+    //
+    // I can imagine that these services would be potentially useful in core Alfresco.
+    // However they are not yet full services and couldn't be moved as is into core.
+    // They solve a very specific RM problem in a fairly generic way that should allow
+    // someone to use them as the basis for fuller services within core.
+    //
+    // The problem they solve is that of 'classified renditions' whereby the classification
+    // metadata on a node should appear to be on its renditions as well. This particular problem
+    // is simplified by the fact that renditions are not 'normal' nodes, as they are usually
+    // not accessed directly. This implementation also relies on the fact that RM already
+    // has interceptors for checking content classification and we can programmatically add
+    // the calls to metadata referral within the ContentClassificationService.
+    //
+    // To solve the problem of Metadata Referral in a general way would require the provision
+    // of 'MetadataReferral' interceptors that could sit in front of the NodeService. Only in this
+    // way could the services be used declaratively, thus minimising their impact on calling code.
+    // To add these to core would require careful assessment of their impact, not least in
+    // performance terms. This work is beyond RM's scope at this stage.
+    // The addition of such interceptors to the NodeService would also ensure that any metadata
+    // returned to e.g. Share for a particular node could automatically include 'linked' metadata
+    // which would be important.
+    //
+    // There are further enhancements that should be considered if these were developed into
+    // fuller services including the automatic registration of behaviours (onAddAspect, onRemoveAspect)
+    // for the aspect types which are linked. Currently these behaviours need to be hand-coded.
+    // See ClassifiedAspect.java for an example.
+
     private ReferralRegistry registry;
     private NodeService      nodeService;