Now that is a stellar bug report. ________________________________ From: Bas Gooren <b...@iswd.nl> Sent: Sunday, July 25, 2021 12:06 AM To: users@wicket.apache.org <users@wicket.apache.org>; Sven Meier <s...@meiers.net> Subject: Re: Possible bug / edge case found where page is not detached
Hi Sven, Done - https://issues.apache.org/jira/browse/WICKET-6908 Met vriendelijke groet, Kind regards, Bas Gooren Op 24 juli 2021 bij 10:29:38, Sven Meier (s...@meiers.net) schreef: Hi Bas, that sounds like a bug. Your quickstart didn't make it through the mailing list, would you please attach it to a new Jira issue? Thanks Sven Am 23. Juli 2021 19:30:46 MESZ schrieb Bas Gooren <b...@iswd.nl>: >Hi all, > >Today I spent the better part of my day investigating a bug report >regarding a hibernate LazyInitializationException. >Since we use detaching models everywhere and (in general) never see >such >issues anymore, this one was interesting :-) > >After much debugging I found out what is happening. > >We have a page which has a database model + links for prev/next item >(in >the database). >When the users double-clicks on one of the links, the first click is >OK, >and the second click throws a StalePageException during request cycle >processing. > >So far, normal. > >However, stepping through the wicket code, this is what happens: > >1) Resolve to ListenerRequestHandler, execute it, throws >StalePageException >2) exception mapper handles this and we execute a >RenderPageRequestHandler, >which re-renders the page >3) the request cycle detaches, which delegates in part >to RequestHandlerExecutor.detach() >4) The handlers to detach are both handlers from step 1 and 2; During >the >detach of ListenerRequestHandler, it initializes ListenerLogData, which >(in >the PageLogData ctor) throws the StalePageException again! >5) The second handler (RenderPageRequestHandler) is not detached, thus >all >models in the page are not detached >6) The user clicks on a link and boom, the models are all still >attached >and there we get the LazyInitializationException > >I think that (a) RequestHandlerExecutor.detach() should ensure all >handlers >are detached, and (b) that failing to collect LogData should not stop >the >detaching of a request handler. > >What do you think? > >I tried to make the simplest possible Quickstart to demonstrate this. > >Weird stuff: on the homepage of the quick start, the page is properly >detached when a stale link is clicked; >On another (test) page, the page is not properly detached. > >Steps to reproduce: > >Run Quickstart >Click on “Test” link on homepage >Observe that the following is logged: > >Model still attached? false >Page detaching > >Now click on "Click me (stale link)!” >Now refresh the page (re-render) > >Observe that the following is logged: > >Model still attached? true >Page detaching > >—> So the page was not detached > >These steps don’t have the same result on the homepage. So my guess is >there is some relation to the fact that we are interacting with a >stateful, >non-mounted page. > >Met vriendelijke groet, >Kind regards, > >Bas Gooren [EXTERNAL EMAIL] CAUTION: This email originated from outside of Telenav. DO NOT CLICK links or attachments unless you recognize the sender and know the content is safe.
