Using CheckLogin tag from within tiles

[Alan P Sexton <A....@cs.bham.ac.uk>]

I am switching from plain JSP to using tiles. I was using a CheckLogin
tag on my JSP based on the one in the example for struts. This checks if
there is a valid user in the session and, if not, creates an ActionError
indicating that the session has timed out and forwards to logon.

Now I have a simpleLayout.jsp similar to that in the tiles section of
the Chuck Cavaness's online book draft: I insert a header, a body and a
footer in the simpleLayout for my normal pages.

Now I have a problem with the CheckLogin tag:

- If I put it in the body insert, then when the login check fails
  (because of session timeout) it throws an exception saying that it
  couldn't forward because the output was already committed (I presume
  that the preceding tiles do a flush).

- If I put it at the top of the simpleLayout.jsp (which I thought would
  be before anything was flushed) then it detects the error (and creates
  the correct ActionError) but the forward to the logon page doesn't
  work (the current page is displayed) and the page skip of the
  CheckLogin tag doesn't work.

Can anyone explain to me what is going on and how to fix it?


Alan Sexton




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Re: Using CheckLogin tag from within tiles

[James Mitchell <jm...@telocity.com>]

There have been many "best practices" published (media) and posted (users
list) over the last year or so that, if followed, can/would elimiate these
kinds of issues.

By forcing all interactions with your webapp to go through your custom
actions, you can keep your "check for session expire" code in your action
classes and not have to rely on your jsp to enforce it.

I typically do this in an abstract BaseAction which all actions (except
those not requiring authentication or session data) are required to extend.

> - If I put it in the body insert, then when the login check fails
>   (because of session timeout) it throws an exception saying that it
>   couldn't forward because the output was already committed (I presume
>   that the preceding tiles do a flush).

By placing my "is session expired" code in the base action, I do not have to
replicate the check anywhere else, which elimiates this issue.


> - If I put it at the top of the simpleLayout.jsp (which I thought would
>   be before anything was flushed) then it detects the error (and creates
>   the correct ActionError) but the forward to the logon page doesn't
>   work (the current page is displayed) and the page skip of the
>   CheckLogin tag doesn't work.

Not sure why this is happening, but see above for avoiding it as well.

Hope that helps.
James Mitchell


----- Original Message -----
From: "Alan P Sexton" <A....@cs.bham.ac.uk>
To: <st...@jakarta.apache.org>
Sent: Sunday, October 06, 2002 1:26 PM
Subject: Using CheckLogin tag from within tiles


>
> I am switching from plain JSP to using tiles. I was using a CheckLogin
> tag on my JSP based on the one in the example for struts. This checks if
> there is a valid user in the session and, if not, creates an ActionError
> indicating that the session has timed out and forwards to logon.
>
> Now I have a simpleLayout.jsp similar to that in the tiles section of
> the Chuck Cavaness's online book draft: I insert a header, a body and a
> footer in the simpleLayout for my normal pages.
>
> Now I have a problem with the CheckLogin tag:
>
> - If I put it in the body insert, then when the login check fails
>   (because of session timeout) it throws an exception saying that it
>   couldn't forward because the output was already committed (I presume
>   that the preceding tiles do a flush).
>
> - If I put it at the top of the simpleLayout.jsp (which I thought would
>   be before anything was flushed) then it detects the error (and creates
>   the correct ActionError) but the forward to the logon page doesn't
>   work (the current page is displayed) and the page skip of the
>   CheckLogin tag doesn't work.
>
> Can anyone explain to me what is going on and how to fix it?
>
>
> Alan Sexton
>
>
>
>
> --
> To unsubscribe, e-mail:
<ma...@jakarta.apache.org>
> For additional commands, e-mail:
<ma...@jakarta.apache.org>
>
>


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