Dynamic JSF GUI

Question

Hi
I have a problem with creating dynamic GUIs. I have tried it the way it is described in Hans Bergstens book chapter 15, but it does not work. This may be because I am using WebSphere Application Developer 5.1.2 with a Tomcat 4.0.6.2 plugin. I do always get an "java.lang.IllegalStateException" when performing the second code line:
ServletResponse response = (ServletResponse)context.getExternalContext().getResponse();
OutputStream os = response.getOutputStream();" //Error is generated
BUT there seems to be a slightly different way to generate dynamic user GUIs. This looks like this:
//begin
HtmlPanelGrid grid = new HtmlPanelGrid();
HtmlOutputText title = new HtmlOutputText();
title.setValue("This is my component!");grid.getChildren().add(title);
//end
I have just seen that code in this forum and I have no idea what I should make with it. How does it work to make a GUI this way? How and where is it rendered?
Thanks

Answer 1

What I need is a JSP that has a tag which should look like this:
<pre>
<f:view>
<hx:scriptCollector id="scriptCollector1">
<h:form styleClass="form" id="form1">
<myTag: generateGUI />
</h:form>
</hx:scriptCollector>
</f:view>
</pre>
Alternatively it would be possible to use something else than a tag.
The Tag should then be able to generate the GUI.
<pre>
public class GUITag extends TagSupport
public int doStartTag()
HtmlCommandButton button = new HtmlCommandButton();
button.setId("myButton1");
button.setValue("button");
MethodBinding mbButton = application.createMethodBinding("#{InputValueChanged.print}", null);
button.setAction(mbButton);
component.getAttributes().put("action", mbButton);
//try
button.encodeBegin(facesContext);
button.encodeChildren(facesContext);
button.encodeEnd(facesContext);
//catch block
</pre>
So for example here a button should be generated in the GUI. This button should work. This means when pressing the button the print method of the InputValueChangedBean should be performed. And this does not work at the moment.
The important thing is that the JSP must not contain any JSF code like:
<pre>
<h:outputText ....
</h:outputText>
</pre>
This is because at the beginning of the JSP rendering process I have no idea which components are going to be displayed on it. What will be displayed on the JSP stands in an XML file. This XML file does not only contain the GUI information for one page, it does contain all the GUI information for the entire WebApplication. Depending on which button the user clicks on the dynamically generated GUI a different part of that XML file will be rendered (made to a GUI). So the user sees something different.
I have also thought about using a custom presentation layer as described in chapter 15 of your book. But as far as I have understood that I have to create a ViewHandler. As a result of that the entire GUI of the WebApplication is then rendered using that ViewHandler. And this means I am not longer able to use normal JSPs (I would need to use the ViewHandler and normal JSPs together. So one part of the WebApplication should be rendered using the ViewHandler and the other part of the WebApplication should consist of normal JSPs).
Is there any possibility having one part of the WebApplication rendered by the information of an XML file and a different part of the same WebApplication to be rendered the normal way by using JSPs with JSF tags?