Update object only when form is submitted about ember_data_example

[CodeOfficer]

We used https://github.com/derickbailey/backbone.memento for this in my recent Backbone project. I'd love to see what the Ember community comes up with. Ember-data seems like it might be a while.

[dgeb]

@CodeOfficer - Thanks for the pointer. Memento looks like it takes a pretty rigorous approach, including a change stack as well as support for collections. The difficulty in writing an ember-data example is that I want to do things "the ember-data way", even though that may not have been worked out yet. Since this seems like a pretty common pattern, I would expect support for it in ember-data eventually.

[dgeb]

Form edits are now contained in transactions, which are committed on submit() or rolled back on cancel().