Please send your changes as a "cvs diff -u".
john mcnally
Glenn Golden wrote:
>
> I'm working on Jetspeed, and am tracking down a problem with some of the
> Action code in Jetspeed, which was recently changed to start calling for a
> URL redirect. With Internet Explorer, this doesn't work.
>
> I'm proposing some chages to Turbine to better support the ability to call
> for a URL redirect in an Action class.
>
> Bug: IE hangs when leaving the Jetspeed customizers... I don't know how
> widespread this problem is, is it just IE 6 on XP? Is it just Jetspeed
> running with jdk 1.4.0 in Tomcat 4.0.2? Whatever - it's a problem, and we
> are doing something against the HTTP rules.
>
> Problem: last month, many Jetspeed Actions were modified to use a redirect
> on cancel or done. Code like this in MultiColumnControllerAction.java:
>
> // bring logged on user to homepage with internal redirect
> DynamicURI duri = new DynamicURI(data);
> data.getResponse().sendRedirect(duri.toString());
>
> Note the comment refers to "internal redirect", but this is a real HTTP
> redirect attempt. After this is done in the action, the page goes on to
> execute the screen. It known nothing about the redirect. It goes on to
> write stuff to the response.
>
> HTTP / servlet rules are that a) a redirect can be placed into the response
> only before anything has been written to the response, and b) once the
> redirect is placed, nothing may be written. It seems that our violation of
> this rule is messing up IE.
>
> Comment: I *really* like the idea of being able to use a redirect in an
> action to end a customization to get the browser URL back to a good URL.
>
> Solution: Fix Turbine. Turbine should not let us make this mistake. Or
> better, Turbine should have a well defined and supported way to call for a
> redirect from an Action. The Page code that is messing us up is in
> Turbine's DefaultPage. And a final mess up is made in the Turbine servlet's
> doGet().
>
> 1) Define a standard in Turbine for an action to make an HTTP redirect.
> RunData already has get/setRedirectURI(), and just setting this to a
> non-null non-blank value in an Action should be enough to tell Turbine that
> we want a redirect.
>
> 2) Modify DefaultPage doBuild() to, after running the action, check for a
> redirect, and do whatever is needed. If we standardize on
> "RunData.setRedirectURI()", then the following code inserted in doBuild()
> after the action call would work:
>
> ActionLoader.getInstance().exec ( data, data.getAction() );
> if ((data.getRedirectURI() != null) && (data.getRedirectURI().length() > 0))
> {
> // directly set the response object for a redirect
> data.declareDirectResponse();
> data.getResponse().sendRedirect(data.getRedirectURI());
> return;
> }
>
> 3) Turbine doGet() must make sure not to inadvertently create an output if
> one has not yet been created! This is what it does now in the finally()
> block with "data.getOut().close();". getOut() makes the PrintWriter, and
> even closing it right away causes IE to get messed up. We need this code
> instead:
>
> if (data.isOutSet()) data.getOut().close()
>
> - Glenn
>
> --------------------------------------------
> Glenn R. Golden, Systems Research Programmer
> University of Michigan School of Information
> [EMAIL PROTECTED] 734-615-1419
> http://www-personal.si.umich.edu/~ggolden/
> --------------------------------------------
>
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