Howto: display dynamic form on tree selection (jdev 11gR1)

Question

Heya,
another question by myself, hoping for an advice.
I finally made a tree including different types of "objects" into one tree (based on ADF BC). Simple example use case used in this post: displaying employee hierarchy PLUS assigned projects per employee.
So my current problem is: what is the "way to go" to change the form in the "content" facet (made a simple splitter layout with tree in left facet and "content" in right facet) AND binding the data to it? Clicking on an employee would open the employee form and load data for selected employee into it, but clicking on a project would open the project form and loading data for selected project into it. I have all data available in the tree application module and the decision "what to display" is based on one of the attributes.
All tutorials I found so far for master/detail are kinda "static" (linking employee tree to employee form) and I can't figure out how to do want I want to do.
Is this possible going the declarative way? If yes, how? Or do I have to code something? If yes, how? No need for actual code, just need a hint what to look for.. feeling lost atm.
Any help is highly appreciated. :)

Answer 1

Hi,
here's how you do it
1. Create a iterator binding for the project ViewObject (choose a ViewObject instance that is not dependent to the employees ViewObject you use as the tree top level)
2. In the binding editor, expand the Data Source entry (below the rule attribute configuration) and create an EL expression that references the iterator bindingyou created
This ensures that selecting an emplloyee is synchronized with the Employee iterator used to build the top level nodes and the selected project is synchronized with the project iterator node.
3. Add a switcher component to switch between the employee and the project edit form
4. Create a facet in the af:switcher that has the name of the full employee view object e.g. adf.mysample.EmployeesView
5. Create a facet in the af:switcher for the full name of the Project VO
6. Drag and drop the EmployeeView entry from the data Controls palette as a form into the Employees facet
7. Do the same for the Projects (make sure you use the Projects VO that is not depedent)
Set the default value of the switcher too point to the facet that should be shown by default. The value of the switcher set to an EL that points to a managed bean method or memory attribute. Upon selecting a node (you can use the tree node selection listener) you access the selected tree node. The selection listener code woud look as shown below
  //tree reference can be obtained from the selectionListener event (Source) or from a JSF component binding property reference
  //example uses the latter
  RichTree tree = this.getTree1();
  //get selected row keys. This could be a single entry or
  //multiple entries dependent on whether the tree is
  //configured for multi row selection or single row selection
  RowKeySet rks = tree.getSelectedRowKeys();
  Iterator rksIterator = rks.iterator();
  //assuming single select use case. Otherwise, this is where you
  //need to add iteration over the entries in the multi select use case
  if (rksIterator.hasNext()){
    //a key is a list object that containe the node path information for the
    //selected node
    List key = (List)rksIterator.next();
    //determine the selected node. Note that the tree binding is an instance of
    //JUCtrlHierBinding
    JUCtrlHierBinding treeBinding = null;
    //We can get the binding information without using EL in our Java, which you always should
    //try to do. Using EL in Java is good to use, but only second best as a solution
    treeBinding = (JUCtrlHierBinding) ((CollectionModel)tree.getValue()).getWrappedData();
    //the row data is represented by the JUCtrlHierNodeBinding class at runtime. We get the node value
    //from the tree binding at runtime     
    JUCtrlHierNodeBinding nodeBinding = treeBinding.findNodeByKeyPath(key);
        //the JUCtrlHierNodeBinding object allows you to access the row data, so if all you want is to
    //get the selected row data, then you are done already. However, in many cases you need to further
    //distinguish the node, which is what we can do using the HierTypeBinding
    String nodeStuctureDefname = nodeBinding.getHierTypeBinding().getStructureDefName();
   //determine the selected node by the ViewObject name and package
   String employeesDef = "adf.mysample.EmployeesView";
   String projectDef = "adf.mysample.ProjectsView";
  if (nodeStuctureDefname.equalsIgnoreCase(empoyeesDef)){
     // change value reference used in af:switcher and partially refresh the af:switcher component to show the edit form
     // e.g. change the value of the refrenced memory attribute or managed bean variable
   else if (nodeStuctureDefname.equalsIgnoreCase(projectDefDef)){
     // change value reference used in af:switcher and partially refresh the af:switcher component to show the edit form
     // e.g. change the value of the refrenced memory attribute or managed bean variable
   else{
    //what the heck did the user click on? Ask him ;-)
   }Frank