Rails - Apr 2006 - respond_to causes DoubleRenderError?

I have a custom authentication plugin that redirects users to a login
site if they aren''t already authenticated and their session
hasn''t
timed out. I had things working fine with straight http requests, but
wanted to add support for ajax requests. I thought this would be a
simple matter of replacing all of my "redirect_to <blah> and return
false" calls with something like "redirect <blah> and return
false",
where the redirect method wraps a respond_to block. For example:

    def redirect(url)
      respond_to do |wants|
        wants.html { redirect_to url }
        wants.js { render :update do |page| page.redirect_to url end }
      end
    end

However, this causes a DRE when I deployed it on my FCGI production
server. In fact, removing the wants.js line so that the function is
just

    def redirect(url)
      respond_to do |wants|
        wants.html { redirect_to url }
      end
    end

still triggers a DRE. The only time things work as expected are when
the function reads:

    def redirect(url)
        redirect_to url
    end

It seems that the respond_to method is breaking my login plugin. I''m a
little confused as to why this would hapen, though. Has anyone seen
this behavior before?

--
Ryan

2006/4/7, Ryan Nielsen <rpnielsen@gmail.com>:
>     def redirect(url)
>       respond_to do |wants|
>         wants.html { redirect_to url }
>         wants.js { render :update do |page| page.redirect_to url end }
>       end
>     end
Are you sure you are not doing any render work in the CALLERs of redirect ?

Check the stacktrace to see where the second render occurs.

Hope that helps,
--
Fran?ois Beausoleil
http://blog.teksol.info/

Nope, there are absolutely no calls to render or redirect_to on the
stack. I wish there were, that''s the first thing I checked! Here is
the backtrace:

ActionController::DoubleRenderError:
    `redirect_to''
    `redirect''
    `respond''
    `respond''
    `respond_to''
    `redirect''
    `validate_user_identity''
    `call_filters''
    `call_filters''
    `before_action''
    `perform_action_without_benchmark''
    `perform_action_without_rescue''
    `measure''
    `perform_action_without_rescue''
    `perform_action''
    `process_without_filters''
    `process_without_session_management_support''
    `process''
    `dispatch''
    `process_request''
    `process!''
    `each_cgi''
    `each_cgi''
    `process!''
    `process!''
    dispatch.fcgi:24

You can see my plugin''s calls to
''validate_user_identity'' and
''redirect'' on the stack, but no calls to
''redirect_to'' or ''render''.
Basically, stuff works when I don''t have a respond_to but breaks when
I do have a redirect_to. This is on 1.1.1, fwiw.

--
Ryan

On 4/7/06, Francois Beausoleil <francois.beausoleil@gmail.com>
wrote:
> 2006/4/7, Ryan Nielsen <rpnielsen@gmail.com>:
> >     def redirect(url)
> >       respond_to do |wants|
> >         wants.html { redirect_to url }
> >         wants.js { render :update do |page| page.redirect_to url end }
> >       end
> >     end
>
> Are you sure you are not doing any render work in the CALLERs of redirect ?
>
> Check the stacktrace to see where the second render occurs.
>
> Hope that helps,
> --
> Fran?ois Beausoleil
> http://blog.teksol.info/
>
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