Cannot find conversation when using a link during page-setup

[daniell]

Hi!

I've an application running on JBoss AS 5.1.0.GA with Seam 2.2.2.Final.
Most of the time, everything works fine ;)

But if a user with a low bandwidth is using the webapp, there is a chance of being redirected to the no-conversation-view-id - even if a conversation is running:

On (one of the) problematic page(s), there is a form containing a table containing some information and a h:commandLink in each table row. When entering this page, a new conversation is started.
Usually the whole page is populated to the user immediately. But it may be possible that it takes some time until the page is fully loaded. The user sees the page building up row per row.
If the user is fast enough and uses one of the command-links while only a part of the page is loaded, he will be redirected to the no-conversation-view-id.

I guess the problem is the following: Even with javax.faces.STATE_SAVING_METHOD=server, JSF appends a hidden field javax.faces.ViewState in each form. This auto-generated identifier token, passed through the hidden form field, is used to identify the component tree object in the users server-side session.

Since the page is not fully loaded (or displayed) by the browser, the POST-request is sent without the ViewState. I was able to verify this with wireshark: in the standard case the identifier token is part of the POSt while in the problematic case it is not.

So the component-tree cannot be found, seam writes No stored conversation into the log-file (but no exception) and redirects to the no-conversation-view-id with the faces message The conversation ended, timed out or was processing another request.

Is this a known issue or am I doing something wrong? Is it possible to move the hidden field containing the javax.faces.ViewState to the beginning of each form instead of the end?

Btw: to handle concurrent requests there's a RichFaces queue and a defined concurrent-request-timeout in components.xml.

[cosmo]

Isn't it easier to handle this in a Gmail way? I mean not letting the user interact until the page is fully load, which I'm sure can be achievable by some JQuery magic for instance.

Also, (and I know this is a little off topic) if bandwidth/response time is the problem, may be tunning up your application could improve user experience with it.

[daniell]

Hi Aldo!

Thank you for your response! I already had some similar idea by preventing the browser to execute scripts until the page is fully loaded - but didn't find anything suitable for any browser (without user action).
There are only some browser-specific settings like the Opera's Delayed Script Execution=1.

But the JQuery-Plugin sounds pretty useful. I will give it a try.

And yes, I know that there are some places to optimize the application with respect to bandwidth usage (the posted article is really informative) - but anyway: since users may use very poor connections the problem only becomes less likely ;)