Richtree on Demand Loading

[gewuerzgurke]

Hi everyone,

I've got a problem using rich:tree to display some data. I'm using Richfaces 3.2.2 GA, Seam 2.2.0 GA on a Jboss 5.0.1 GA.

I want the tree to display some rootnodes. By clicking on one rootnode the necessary data must be loaded by my component. Because I've got a tree with around 22000 nodes this kind of lazy-loading is the only possible way to display that much data.

Here is my xhtml:

<h:panelGrid columns="2">
 <rich:panel id="selectedNodes">
  </rich:panel>
 <rich:tree value="#{selectCategoryTree.nodes}" var="node" id="tree" treeNodeVar="nodeTree" ajaxSubmitSelection="true" switchType="ajax" ajaxKeys="#{null}" changeExpandListener="#{selectCategoryTree.processExpansion}" nodeSelectListener="#{selectCategoryTree.processSelection}">
  <rich:treeNode type="parent" icon="/img/iconset/box_48.png" iconCollapsed="/img/iconset/arrow_right_48.png" iconExpanded="/img/iconset/arrow_down_48.png" >#{node.name}
  </rich:treeNode>
 </rich:tree>
</h:panelGrid>

And the selectCategoryTree Component:

@Name("selectCategoryTree")
@Scope(ScopeType.SESSION)
public class SelectCategoryTree {
     @Logger
     Log log;
     
     @In
     EbayDriver ebayDriver;
     
     private TreeNode<Category> root;
     
     private List<TreeNode<Category>> selectedCategories;
     
     protected void addNode(TreeNode<Category> parent, List<Category> categories, Integer level) {
          int count = 0;          
          for( Category cat : categories ) {
               if( ! cat.getLevel().equals(1) && ! cat.getInternalParentId().equals(parent.getData().getInternalId()) ) {
                    continue;
               }
               if( cat.getLevel().equals(level) ) {                    
                         TreeNode<Category> add = new TreeNodeImpl<Category>();
                         add.setData(cat);          
                         if( ! cat.getLevel().equals(1) ) {
                              add.setParent(parent);
                         }
                         parent.addChild(count++, add);                              
               }
          }          
     }
     
     public void processExpansion(NodeExpandedEvent event) {
          HtmlTreeNode source = (HtmlTreeNode)event.getSource();
          UITree tree = ((HtmlTreeNode)source).getUITree();
          Object rowKey = tree.getRowKey();
          TreeNode<Category> selectedNode = tree.getModelTreeNode(rowKey);
          addNode(selectedNode, ebayDriver.getEbayChildCategories(selectedNode.getData()), selectedNode.getData().getLevel()+1);
     }
     
     public void processSelection(NodeSelectedEvent event) {
          HtmlTree tree = (HtmlTree)event.getComponent();                         
          Object rowKey = tree.getRowKey();
          TreeNode<Category> selectedNode = tree.getModelTreeNode(rowKey);
          addNode(selectedNode, ebayDriver.getEbayChildCategories(selectedNode.getData()), selectedNode.getData().getLevel()+1);
     }
     
     protected void buildNodes() {
          List<Category> categories = ebayDriver.getEbayCategories();
          Category internalRoot = new Category();
          internalRoot.setName("Root");
          root = new TreeNodeImpl<Category>();
          root.setData(internalRoot);               
          root.setParent(null);
          // Build demo stuff
          addNode(root, categories, 1);
     }
     
     public TreeNode<Category> getNodes() {
          if( root == null )
               buildNodes();
          
          return root;
     }

     public List<TreeNode<Category>> getSelectedCategories() {
          return selectedCategories;
     }

     public void setSelectedCategories(List<TreeNode<Category>> selectedCategories) {
          this.selectedCategories = selectedCategories;
     }
}

Now I'm faced with different problems:

1. The root nodes don't contain childs (they should be loaded on demand). So I cannot really expand the single root nodes


2. When I select a node the right listener is called and data is fetched, but isn't displayed


3. Google'd around a lot and even bought a Richfaces book, cannot figure out if it's even possible to load data on demand for rich:tree

Any ideas?

Best Regards,

Alexander Müller

[franckoliver]

hi Alexander,

did you figute out how to load the data on demand and expand a rich:tree. I stuck in it for weeks. Can you please be you can provide here, how you fix it? thanks a lot.

[aareshchanka]

You are right, if you are using

rich:treeNode

it's impossible to rerender single node.

There are 2 ways:
1-st is to rerender whole tree after selection listeners are invoked
2-nd is to use treeNodeAdapter

see richfaces demo My Link

[franckoliver]

thanks for your reply. I'm using rich:node to render data from a database at run time on user request, because the data model is too large. So i'm trying to update the data model, when the user select or expand a node in the tree(listener will be call). Do you know, if i can achieve it with the treeNodeAdapter? or how?

[aareshchanka]

I created example and uploaded it to google code, see sources.

Tree is loaded dynamically on expand. Database is empty just insert some data manually. Project runs from eclipse on Jboss 4.3, add tree-ds.xml to deploy folder, and mysql jdbc driver to libs to run it.

Richfaces dynamic node load example

[franckoliver]

hi,

i just want to thank you, your example works and help me a lot.