On Nov 19, 2009, at 2:24 PM, Igor Vaynberg wrote:
> On Thu, Nov 19, 2009 at 2:15 PM, Hawk Newton <[email protected]> wrote:
>> 2. Extend WebRequestCycle.onRuntimeException() to redirect the browser back
>> to the target page instead of the "expired session" error page. This
>> approach has the drawback that the model will be reset which will cause the
>> page to revert to default values. Ultimately, initializing the page using
>> values from a cookie or some other stateful store that is not tied to the
>> user's session would be ideal, if possible.
>
> unless you encode the page class into every url there is no way to
> know what page was being accessed once the session is expired.
I got this working today provided each page is mounted as bookmarkable. I
might be missing some of the long-reaching implications, but here's the code if
anyone is interested in it:
// In my WicketApplication class:
public RequestCycle newRequestCycle(Request request, Response response)
{
return new WebRequestCycle(this, (WebRequest)request,
(WebResponse)response) {
@Override
public Page onRuntimeException(Page page,
RuntimeException e) {
if(e instanceof PageExpiredException) {
IRequestCycleProcessor processor =
WicketApplication.this.getRequestCycleProcessor();
RequestParameters params =
request.getRequestParameters();
// We're just looking for the original
page, not a component on that page.
String interfaceName =
params.getInterfaceName();
// Strip the interfaceName from the
request so we can get the original target
params.setInterfaceName(null);
IRequestTarget target =
processor.resolve(this, params);
params.setInterfaceName(interfaceName);
if(target != null && target instanceof
BookmarkablePageRequestTarget) {
Class<? extends Page> pageClass
= ((BookmarkablePageRequestTarget)target).getPageClass();
RequestCycle.get(); // I'm
not 100% on why I need this.
CharSequence path =
processor.getRequestCodingStrategy().pathForTarget(
new
BookmarkablePageRequestTarget(pageClass));
if(path != null) {
// This is a
bookmarkable page, so lets send the user to the bookmark
RequestCycle.get().setRedirect(true);
throw new
RestartResponseException(pageClass);
}
}
}
return null;
}
};
}
>
>> 3. Use an external store instead of the J2EE session (like a RDBMS) with a
>> data-retention policy so high the chance of a ajax request being issued
>> against a page which has expired is practically nil. We'd also probably
>> need to implement our own encoder to ensure the session id is placed on
>> every link to survive J2EE session invalidation.
>
> or simply set the j2ee session timeout to a high value. servlet
> containers these days can swap inactive sessions to disk to keep the
> memory overhead low. same effect and no need to deal with a database.
>
> -igor
Thank you, with a high enough session timeout and a disk-backed session
overflow we should be good.
-- Hawk
