Where/How do I programmatically build the component tree?

Question

Hi! I'm having a lot of problems trying to make my JSF application work...
Here's the situation:
- I have to display a form (questionnaire) consisting of a tree (form - subforms - sections - groups - questions - checkboxes/dropdowns...). Each of these parts are custom components, with custom renderers.
- This display is only a small part of a wider application (so the custom ViewHandler solution seems impossible to me), and it is done in an imported jsp (using <jstl:import ...>). In this jsp, there is only one component, representing the "root" of the questionnaire, because the structure of the questionnaire is unknown at the beginning.
- I need to build programmatically (in Java) the component tree of my questionnaire (according to the structure loaded from a database) and integrate it in the component tree of the whole application.
- The problem is I can't get this to work properly in the JSF lifecycle (either the restoreState/saveState methods aren't called, or the "main" tree doesn't contain my "sub-tree" although everything is rendered properly...). I searched on a lot of forums, I tried a lot of solutions (new UIComponent() vs. application.createComponent(...) / create the tree in the component constructor vs. in the component renderer... ) but none of them seemed to meet my requirements, since it seems to be a tricky situation.
So, does anyone knows how to achieve this? How and where to build my component tree?
(ask me if a you need more information about my code!)
Thanks in advance!!
Adriano

Answer 1

Bit_happens wrote:
- I'm using the "createComponent" method to build my tree (instead of just calling the component constructor), is that right? For example:
UISubform subformComponent = (UISubform) application.createComponent(UISubform.TYPE);
//UISubform subformComponent = new UISubform();What is the difference with the plain constructor call?You are not implementation dependent then.
- Apparently, I have to explicitly add the panelGroup to the component tree, or else it won't be part of the tree. Is that normal? Shouldn't JSF add it to the tree automatically when it finds it in the JSP? I have to do the following:
UIComponent parent = facesContext.getViewRoot().findComponent("form_subview").findComponent("main_form");
parent.getChildren().add(panel);
panel.setParent(parent);- Is there a difference between creating the "sub-tree" in an ascending way, or in a descending way? I.e. first creating the leaves and then going up the branches until I plug the root component into the main tree, or first creating the root component and then going down the branches until all the leaves are created?No, there isn't.
- I think my custom components themselves should be right, and they're declared in faces-config. It looks like the panelGroup doesn't renders its children, but it should by default, right? When I look at the rendered page source code, the panelGroup is empty:
<span id="form_subview:main_form:formPanel"></span>- Do you think of anything else I should check? Any tricky setting I could have forgot?Try adding existing components to the panelGroup, e.g. HtmlOutputText. If that works, then I rather think there is a flaw in your component.