The admin form of a PortalWorkspace now shows a mapped category system without a restart (issue #1899).

git-svn-id: https://svn.libreccm.org/ccm/trunk@2708 8810af33-2d31-482b-a856-94f89814c4df

ccm-portalworkspace/src/com/arsdigita/portalworkspace/ui/admin/CategoryComponent.java

@@ -22,12 +22,14 @@ import org.apache.log4j.Logger;
 
 import com.arsdigita.bebop.Label;
 import com.arsdigita.bebop.PageState;
+import com.arsdigita.bebop.RequestLocal;
 import com.arsdigita.bebop.SimpleContainer;
 import com.arsdigita.bebop.Tree;
 import com.arsdigita.bebop.event.ActionEvent;
 import com.arsdigita.bebop.event.ActionListener;
 import com.arsdigita.bebop.tree.TreeModel;
 import com.arsdigita.bebop.tree.TreeModelBuilder;
+import com.arsdigita.bebop.tree.TreeNode;
 import com.arsdigita.categorization.Category;
 import com.arsdigita.categorization.CategoryTreeModelLite;
 import com.arsdigita.domain.DomainObjectFactory;
@@ -41,6 +43,7 @@ import com.arsdigita.util.Assert;
 import com.arsdigita.util.LockableImpl;
 import com.arsdigita.web.Application;
 import com.arsdigita.web.Web;
+import java.util.Iterator;
 
 /**
  * CategoryComponent.
@@ -49,8 +52,7 @@ import com.arsdigita.web.Web;
  */
 public class CategoryComponent extends SimpleContainer {
 
-    private static final Logger s_log = Logger
-            .getLogger(CategoryComponent.class);
+    private static final Logger s_log = Logger.getLogger(CategoryComponent.class);
     private ACSObjectSelectionModel m_catModel;
     private CategoryTree m_tree;
     private ApplicationSelectionModel m_appModel;
@@ -63,12 +65,6 @@ public class CategoryComponent extends SimpleContainer {
      * @param appModel
      */
     public CategoryComponent(ApplicationSelectionModel appModel) {
-        // this model means that the server needs a restart
-        // if you want to map a category to this personal portal
-        // AND vice versa - if you remove a domain mapping you need to
-        // restart the server otherwise you will get an exception next time
-        // this Component is viewed.
-        if (m_root != null) {
         setNamespace(WorkspacePage.PORTAL_XML_NS);
         setTag("portal:categoryPanel");
 
@@ -83,7 +79,6 @@ public class CategoryComponent extends SimpleContainer {
         m_error = new Label("");
         add(m_error);
     }
-    }
 
     /**
      *
@@ -150,23 +145,115 @@ public class CategoryComponent extends SimpleContainer {
     /**
      * A TreeModelBuilder that loads the tree from the current category
      */
-    private static class SectionTreeModelBuilder extends LockableImpl implements
-            TreeModelBuilder {
+    private static class SectionTreeModelBuilder extends LockableImpl implements TreeModelBuilder {
+
+        /**
+         * A RequestLocal wrapper for the model. It is necessary to wrap the model into a 
+         * {@link RequestLocal} wrapper because the contents of the model may change. Before this
+         * was introduced the system had be restarted if a new category system was mapped to 
+         * a PortalWorkspace.
+         */
+        final RequestLocal treeModel = new TreeModelRequestLocal();
 
         public SectionTreeModelBuilder() {
             super();
         }
 
+        @Override
         public TreeModel makeModel(Tree t, PageState s) {
+            return (TreeModel) treeModel.get(s);
+
+        }
+
+    }
+
+    /**
+     * The RequestLocal used by the {@link SectionTreeModelBuilder}. 
+     */
+    private static class TreeModelRequestLocal extends RequestLocal {
+
+        public TreeModelRequestLocal() {
+            //Nothing
+        }
+        
+        /**
+         * Provides the initial value for this {@code {RequestLocal}. If a category system
+         * is mapped to the current PortalWorkspace (the current Application instance), the method 
+         * returns a {@link CategoryTreeModelLite} instance. The {link CategoryTreeModelLite} is 
+         * created using the root category of the mapped category system.
+         * If there is no mapping the method returns an instance of {@link EmptyTreeModel}.
+         * 
+         * @param state
+         * @return 
+         */
+        @Override
+        protected Object initialValue(final PageState state) {
             Application app = Web.getWebContext().getApplication();
             Category root = null;
             while (app != null && root == null) {
                 root = Category.getRootForObject(app);
                 app = (Application) app.getParentResource();
             }
+
+            if (root == null) {
+                return new EmptyTreeModel();
+
+            } else {
                 Assert.exists(root, Category.class);
                 return new CategoryTreeModelLite(root);
             }
 
         }
+
+    }
+
+    /**
+     * A simple helper class representing an empty tree.
+     */
+    private static class EmptyTreeModel implements TreeModel {
+
+        public EmptyTreeModel() {
+            //Nothing
+        }
+        
+        @Override
+        public TreeNode getRoot(final PageState data) {
+            return new EmptyTreeRootNode();
+        }
+
+        @Override
+        public boolean hasChildren(final TreeNode node,
+                                   final PageState state) {
+            return false;
+        }
+
+        @Override
+        public Iterator getChildren(final TreeNode node,
+                                    final PageState data) {
+            return null;
+        }
+
+    }
+
+    /**
+     * The root node of an empty tree.
+     */
+    private static class EmptyTreeRootNode implements TreeNode {
+
+        public EmptyTreeRootNode() {
+            //Nothing
+        }
+        
+        @Override
+        public Object getKey() {
+            return "empty";
+        }
+
+        @Override
+        public Object getElement() {
+            return "";
+        }
+
+    }
+
 }

ccm-sci-bundle/bundles/devel/cfg/project.xml

@@ -9,7 +9,7 @@
                     name="ScientificCMS" 
               prettyName="Scientific CMS" 
                  version="2.3.0" 
-                 release="devel-SNAPSHOT-r2691" 
+                 release="devel-SNAPSHOT-r2707" 
                   webxml="sci-web.xml" 
               portletxml="sci-portlet.xml" 
                   webapp="libreccm"