Question about code corner Example#33: How-to open a Bounded Task Flow in a new Browser Tab

Question

Hello All,
I am implementing example #33 in code corner series Oracle ADF Code Corner</title><meta name="Title" content="Oracle ADF Code Corner"><me…
Every thing is going fine, but there is a comment in the java code that I don't understand.
public void onLaunchForEdit(ActionEvent actionEvent) {    
      //access the ADF binding layer and access the tree binding that
      //populates the table
        BindingContext bctx = BindingContext.getCurrent();
        BindingContainer bindings =
                               bctx.getCurrentBindingsEntry();   
        //access the tree binding defined in the ADF binding layer
        JUCtrlHierBinding model =
               (JUCtrlHierBinding) bindings.get("DepartmentsView1");
        //get the current selected row key from the iterator binding
        //referenced from the table binding (tree binding). Of course,
        //I could have used the iterator name directly in the binding
        //lookup, but looking up the tree binding instead allows to
        //change the tree binding iterator dependency to a later point
        //in time without breaking this functionality. Its all about
        //"weak" dependencies that give you flexibility when coding ADF
        String rwKeyString =
               model.getDCIteratorBinding().getCurrentRowKeyString();
        launchWindow(rwKeyString);
What does this comment mean?
         //but looking up the tree binding instead allows to
        //change the tree binding iterator dependency to a later point
        //in time without breaking this functionality. Its all about
        //"weak" dependencies that give you flexibility when coding ADF
Is this a contrast to this line of code?
JUCtrlHierBinding model =
               (JUCtrlHierBinding) bindings.get("DepartmentsView1");
I mean in this line of code we hard coded the tree binding name from the page Def? why getting the tree binding name is a best practice while getting the iterator name is not?

Answer 1

What does this comment mean?
         //but looking up the tree binding instead allows to 
        //change the tree binding iterator dependency to a later point 
        //in time without breaking this functionality. Its all about 
        //"weak" dependencies that give you flexibility when coding ADF 
Is this a contrast to this line of code?
JUCtrlHierBinding model = 
               (JUCtrlHierBinding) bindings.get("DepartmentsView1"); 
Yes, it's exactly this line of code the comment is referring to. If you look at the bindings of a page you see three parts: on the left he bindings, in the middle the executables and on the right side the data control. The statement
JUCtrlHierBinding model = 
               (JUCtrlHierBinding) bindings.get("DepartmentsView1");
access the binding, the tree binding to get the data. if you use the iterator which named 'DepartmentsView1Iterator' you are accessing the executable, the iterator itself. The comment now tell you that if you access the data via the tree binding, that you can change the underlying iterator to point to different data. This you can do without the need to change the code in the been, whihc is good as you (or we all) tend to forget that we have code working on the iterator, so changing things in the bindings will break the application.
Timo