model/SingleJcrNode.java

   1 package org.argeo.jcr.ui.explorer.model;
   2
   3 import javax.jcr.Node;
   4 import javax.jcr.NodeIterator;
   5 import javax.jcr.RepositoryException;
   6 import javax.jcr.Workspace;
   7
   8 import org.argeo.ArgeoException;
   9 import org.argeo.eclipse.ui.TreeParent;
  10
  11 /**
  12  * UI Tree component. Wraps a node of a JCR {@link Workspace}. It also keeps a
  13  * reference to its parent node that can either be a {@link WorkspaceNode}, a
  14  * {@link SingleJcrNode} or null if the node is "mounted" as the root of the UI
  15  * tree.
  16  */
  17
  18 public class SingleJcrNode extends TreeParent implements UiNode {
  19
  20         private final Node node;
  21         private String alias = null;
  22
  23         // keeps a local reference to the node's name to avoid exception when the
  24         // session is lost
  25         // private final String name;
  26
  27         /** Creates a new UiNode in the UI Tree */
  28         public SingleJcrNode(TreeParent parent, Node node, String name) {
  29                 super(name);
  30                 setParent(parent);
  31                 this.node = node;
  32         }
  33
  34         /**
  35          * Creates a new UiNode in the UI Tree, keeping a reference to the alias of
  36          * the corresponding repository in the current UI environment. It is useful
  37          * to be able to mount nodes as roots of the UI tree.
  38          */
  39         public SingleJcrNode(TreeParent parent, Node node, String name, String alias) {
  40                 super(name);
  41                 setParent(parent);
  42                 this.node = node;
  43                 this.alias = alias;
  44         }
  45
  46         /** returns the node wrapped by the current Ui object */
  47         public Node getNode() {
  48                 return node;
  49         }
  50
  51         /**
  52          * Returns the alias corresponding to the repository abstraction that
  53          * contains current node. If the current object is mounted as root of the UI
  54          * tree, the alias is stored in the object. Otherwise, we must browse the
  55          * tree backward to the RepositoryNode.
  56          *
  57          * Alias is then cached in the current object so that next time it will be
  58          * here.
  59          */
  60         public String getAlias() {
  61                 if (alias == null) {
  62                         alias = ((UiNode) getParent()).getAlias();
  63                 }
  64                 return alias;
  65         }
  66
  67         /**
  68          * Override normal behaviour to initialize children only when first
  69          * requested
  70          */
  71         @Override
  72         public synchronized Object[] getChildren() {
  73                 if (isLoaded()) {
  74                         return super.getChildren();
  75                 } else {
  76                         // initialize current object
  77                         try {
  78                                 NodeIterator ni = node.getNodes();
  79                                 while (ni.hasNext()) {
  80                                         Node curNode = ni.nextNode();
  81                                         addChild(new SingleJcrNode(this, curNode, curNode.getName()));
  82                                 }
  83                                 return super.getChildren();
  84                         } catch (RepositoryException re) {
  85                                 throw new ArgeoException(
  86                                                 "Unexcpected error while initializing children SingleJcrNode",
  87                                                 re);
  88                         }
  89                 }
  90         }
  91
  92         @Override
  93         public boolean hasChildren() {
  94                 try {
  95                         return node.hasNodes();
  96                 } catch (RepositoryException re) {
  97                         throw new ArgeoException(
  98                                         "Unexpected error while checking children node existence",
  99                                         re);
 100                 }
 101         }
 102
 103 }