I am using GWTs Activities and Places pretty much as described on http://code.google.com/webtoolkit/doc/latest/DevGuideMvpActivitiesAndPlaces.html and it is all working fine.
What I would like to do is from a particular page navigate to the previous page without using History.back() as I don't want to lose the history state. (I have a page where the user performs an action, on success I want to return to the previous page and keep the history state, on the other hand if they cancel I do want to use History.back() as I do want to lose the state).
The only way I can think of to do this is to create my own Place/History tracking code that listens to Place/History change events and makes the previous Place available to me so that I can call placeController.goto(...)
Is there an easier way of doing this? Am I missing something?
You have to somehow keep track of were to return, because instead of cancel the user can hit the back button, which would be the same as clicking cancel, except there is no code in your application executed, so you have no control.
Secondly if you have the history in the url, the user could navigate directly to that page and then you should know where to go to when the user click ok. Or if the user goes directly to the page, redirect the user to another page.
One approach is to store the return history token in the history token of the page you go to. When the page is finished it can go back(or technically it would be 'go forward') to that page based on the passed return token. (Although with GWT you could easily store the history token in code).