Override isEnabled instead. That way it is visible, even after being clicked when the other person clicked it first. You may have to add some logic in the onClick that says "oops - already in use".
-- Jeremy Thomerson http://www.wickettraining.com On Wed, Dec 23, 2009 at 9:46 AM, Kogel, Jonck-van-der < [email protected]> wrote: > Hi, > I'm having a problem with a multi-user environment. I have a form, which > has an edit button. When a user presses the edit button, I write to the > database that this current user is editing the form. So when another > user comes along and wants to edit it, he gets the message that the form > cannot be edited because it's locked by another user. This works fine > when user A loads the form, presses the edit button and after that user > B comes along. However, if the process is: user A comes along and loads > the form, user B loads the same form, then user A presses the edit > button and after that user B presses it. Then I get an unexpected > runtimeexception and the message: > WicketMessage: Submit Button topBar:edit (path=arfForm:topBar:edit) is > not visible > > Now this obviously has to do with the way I'm determining whether or not > this button should be visible. What I did is extend the Button class and > override the isVisible method. Here I check whether there is no editor, > if so, the button should be visible so the current user can become the > editor. However, since in this situation, user B became the editor while > this user had already loaded the form, the button is no longer valid for > user A but he already has it on his screen. I thought to check this in > the onSubmit method and retrieve the persisted object and check if > nothing had changed in the meantime, but apparently Wicket checks > whether this button should have been visible in the first place. And > since I use LoadableDetachableModel as the underlying model (arfModel) > the updated object is retrieved and Wicket detects that the isVisible > method returns false and throws an error that I'm trying to call the > onSubmit method. > > Does anyone know of an elegant solution for this problem? Please see > below for my implementation of the edit button. > > Thanks, Jonck > > add(new Button("edit") { > @Override > public void onSubmit() { > String username = > ((AppAuthenticatedWebSession)getSession()).getUsername(); > ARF currentArf = arfModel.getObject(); > > ARF persistedArf = arfService.load(currentArf.getId()); > > if (persistedArf.getEditor() == null || > persistedArf.getEditor().equals(username)) { > currentArf.setEditor(username); > arfService.save(currentArf); > } > } > > @Override > public boolean isVisible() { > String editor = arfModel.getObject().getEditor(); > if (editor == null) { > return true; > } > return false; > } > }); >
