how i have handled this so far: if load fails it throws EntityNotFoundException, in requestcycle.onruntimeexception() i check if this is in the stack, and if it is i redirect the user to "object you are working on has been deleted by another user" error page.
-igor On Feb 1, 2008 8:24 AM, Sam Barnum <[EMAIL PROTECTED]> wrote: > Good explanation, I wasn't aware that was how it worked. Time to > switch all my edit pages to use detachable models! > > One more question on this topic (changing the subject of the thread) > > Consider the scenario: > > * Your edit page uses a detachable model to hold your business object. > * The user edits an object succesfully. > * On a later page, the user deletes the object. > * Then uses the back button to navigate back to the edit page, and > hits reload, or tries saving the object again. > > The detachable model will fire, and will fail to load the object from > the DB. Depending on how your DAO is implemented, this will either > return null or throw an exception. Do you have a recommendation on > how to handle this scenario? Would you just check for null/catch the > exception and do a redirect to an error message page? > > Thanks! > > On Jan 31, 2008, at 7:23 PM, Nick Heudecker wrote: > > > Answer inline. > > > > On Jan 31, 2008 8:42 PM, Sam Barnum <[EMAIL PROTECTED]> wrote: > > > >> Question on detachable models: > >> > >> You use detachable models in the contact edit page. It seems like > >> this would cause your changes to be lost if the edit process takes > >> more than one request to complete. > >> > >> If you use the no-arg constructor, the loadableDetachableModel > >> creates a new contact at the beginning of every request. If you > >> enter a name that's too long, a validation message is displayed. Then > >> the detach() is called on the model, and a new Contact is loaded on > >> the next request, erasing your temporary changes. > > > > > > If validation fails, the input isn't copied to the Contact object. > > The form > > input is only copied to the Contact object when the form successfully > > submits. > > > > > >> > >> > >> I may well be misunderstanding something, I'm fairly new to this > >> stuff. It seems that for edit pages you want a non-detachable model, > >> which gets serialized to the session. > > > > > > I had the same misconception when I started using Wicket. > > > > > >> > >> > >> Thanks for taking the time to write this article, and thanks in > >> advance for any clarification on this topic. > >> > >> -- > >> Sam Barnum > >> 360 Works > >> http://www.360works.com > >> 415.865.0952 > >> > >> > >> > >> On Jan 28, 2008, at 11:02 AM, Nick Heudecker wrote: > >> > >>> It's finally up: > >>> http://www.theserverside.com/news/thread.tss?thread_id=48234 > >>> > >>> Thanks to the various reviewers that helped improve both the > >>> content and > >>> quality of the article, including Martijn, Eelco, Igor, Gerolf and > >>> Talios. > >>> > >>> -- > >>> Nick Heudecker > >>> Professional Wicket Training & Consulting > >>> http://www.systemmobile.com > >>> > >>> Eventful - Intelligent Event Management > >>> http://www.eventfulhq.com > >> > >> > > > > > > -- > > Nick Heudecker > > Professional Wicket Training & Consulting > > http://www.systemmobile.com > > > > Eventful - Intelligent Event Management > > http://www.eventfulhq.com > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
