[
https://issues.apache.org/jira/browse/WICKET-4321?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14170701#comment-14170701
]
Martin Grigorov commented on WICKET-4321:
-----------------------------------------
https://github.com/martin-g/component-rendering-default is a demo app showing
how to achieve the requirement from the mail discussion at users@.
> Allow Behaviors to issue a response restart on a render exception
> -----------------------------------------------------------------
>
> Key: WICKET-4321
> URL: https://issues.apache.org/jira/browse/WICKET-4321
> Project: Wicket
> Issue Type: Improvement
> Components: wicket
> Affects Versions: 1.4.19, 1.5.3, 6.0.0-beta1
> Reporter: Carl-Eric Menzel
> Attachments:
> master-allow-behavior-onexception-to-throw-resetresponse-ex.patch,
> wicket-1.4.x-allow-behavior-onexception-to-throw-resetresponse-ex.patch,
> wicket-1.5.x-allow-behavior-onexception-to-throw-resetresponse-ex.patch
>
>
> Currently, when an exception occurs during the render phase, it propagates
> all the way out to the request cycle. Components can't react at all,
> behaviors are only called to allow them to clean up any resources.
> This strikes me as a bit inflexible, since that means any exceptions thrown
> e.g. by a LoadableDetachableModel or any other lazy loading construct can not
> be handled in the page or the component where they occur. It always leaks out
> to the RequestCycle (or its listeners). I have a number of models that do
> remote calls to load required data. If that doesn't work, I'd like to decide
> what to do close to where it happens - in the component.
> If an exception happens during rendering, a component probably shouldn't do
> much anymore, since who knows what state it's in. But a behavior is isolated
> enough that it could decide to show a new page, for example. I propose that
> the code calling Behavior#onException catches not just all Throwables, but
> ResetResponseException and its subclasses, and rethrows the last one it gets
> of those. This way the default behavior is unchanged, all behaviors will be
> called to clean up their resources, and if a behavior decides, based on the
> exception, to render a new page, it can do that. If more than one wants to do
> it, the last one wins.
> I will attach patches for all three major branches, including tests that
> demonstrate the new behavior and prove that nothing is broken.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
