How to implement tabs and workspaces within tabs.

[Scott Updike]

I want to create tabs within my Struts application where once a tab is selected, there will be navigation links down one side, and when links are selected, the remainder of the tab area will serve as the "workspace" for displaying the corresponding JSP page. I have tried using the struts-display tag library and have been able to generate tabs and panels for my links, but I'm not sure how to direct the jsp output to a specific panel in a tab.

Is there a better method to do this? I would like some possible suggestions on ways of accomplishing this that has ample documentation. I know this is a very common design these days, so I know there has to be a better way (or at least one with more documentation than struts-display library). Just looking for suggstions on technologies/frameworks that I could start investigating.

Thanks in advance,
Scott

[Bear Bibeault]

I've always just used good old HTML, CSS, JavaScript and an iframe to hold the "workspace".

[Scott Updike]

Great suggestion. When I try using the iframe tag (pointing to test.jsp) I get the 404 resource not found error in Tomcat. Here's how I have it coded:

<IFRAME ID=adminlist src="/WEB-INF/jsp/mlist.jsp">
</IFRAME>

All my jsp files are kept in Tomcat under the /WEB-INF/jsp/ directory. Do I need to do anything differently? Usually I can just put the path from web app root directory to jsp directory and the app can find the files. Why is this different?

Scott

[Ben Souther]

Servlet containers do not allow web access to files under the WEB-INF directory.

In and MVC environment (such as with Struts), you typically forward to any JSPs. The browser is not requesting them directly.
To preserve your MVC archetecture, create a controller servlet that forwards to these JSPs using a requestDispatcher. Otherwise, move the JSPs out from under WEB-INF.
[ May 19, 2006: Message edited by: Ben Souther ]

[Scott Updike]

In my application, I have an action servlet that dispatches to one jsp, but now with iframes, that jsp page contains two iframe tags that both point to separate jsp pages. So, I'm dispatching to one jsp file that needs to refrence two other jsp files contained in iframe tags.

I hope I'm following your advice correctly. If not, please point me to some reference material on this type of thing. I'm just looking for a simple example (with code snippets).

Thanks for everyone's patience.
Scott

[Ben Souther]

Remember, in a page with frames, each frame generates a completely seperate request.

You could either

enhance your controller so that is knows how to dispatch to different JSPs according to the URL (preferred).

Create servlet entries and servlet-mappings for each of your frame JSPs.

Move the JSPs out from under the WEB-INF directory so that they can be accessed directly from a browser.

[Scott Updike]

Are you saying that I would code the iframe SRC property in a way that the controller knows that this request is coming from this particular frame (and only this frame)?

I think I need an example. Can you suggest a link/book/paper that has a simple example of how to do this?

Again, many thanks.
Scott

[Ben Souther]

Here's one approach.

Lets say you have one controller for the app.
Set up one mapping that grabs any requests that end with ".do"

    <servlet-mapping>
        <servlet-name>ControllerServlet</servlet-name>
        <url-pattern>/*.do</url-pattern>
    </servlet-mapping> 

Now, lets suppose you have 3 JSPs (a frameset, a menu, and a main page)
Your framset (index.do) will have two frame tags:

<frameset cols="20%, 80%">
  <frame src="menu.do" />
  <frame src="main.do" />
</frameset>

Now in your controller, write code that analyzes the URI and forwards to the proper JSP according to the URI

If URI ends with "main.do"
   forward to the main.jsp page
else if URI ends with "menu.do"
   forward to the menu.jsp page
else
   forward to the index.jsp page
 
// Side note: 
// The command pattern is a very popular way of implementing this logic

When you hit the initial page, the servlet will forward to the index.jsp (your frameset page) page. Once the page loads in the browser, the browser will fire off two new requests, one for the menu and one for the main page.
The controller will analyze each of these requests and forward to the correct JSP.

[Scott Updike]

Wow. Great response. I'll work with it and see where it goes.

Thanks a lot for taking the time to provide an example. I'm also just starting the chapter on the command design pattern - what great timing.

Scott

[Scott Updike]

Ok, I have one last question. When I try and add the frameset tags into my jsp (my tab actually) I don't see any output at all. I would at least expect to see empty frames or frames with the "Page not found" error, but I don't see the outlines of the frames at all. Here's my main display page:

<%@ taglib uri="/tags/struts-html" prefix="html" %>
<%@ taglib uri="/WEB-INF/struts-layout.tld" prefix="layout" %>
<head>
<layout:skin/>
</head>

<html>
<body>
<layout:tabs styleClass="FORM" width="100%">
<layout:tab key="Administration" width="50">
<frameset cols="20,*">
<frame src="display.do" />
<frame name="workspace" />
</frameset>
</layout:tab>
</layout:tabs>
</body>
<html>


Where the controller forwards the display.do to a jsp page which lists my links. What's interesting is that when I was playing around with the iframe tag, I was getting it to display, but when I switched to the frame tags, I see nothing - just an empty tab. I really like the functionality of the frame tag as opposed to iframes.

Do you know if there are any known issues with having frameset and frame tags within a display:tab tag?

Thanks,
Scott

[Ben Souther]

I'm not a big user of Struts so I'm not sure what the tab tag does.
You might want to ask that this thread be moved into the Struts forum.