How to revert/undo local changes to an Activerecord object?

Question

Is there a way to undo/revert any local changes to an Activerecord object. For example:

user = User.first
user.name # "Fred"
user.name = "Sam"
user.name_was # "Fred"

user.revert
user.name # "Fred"

I know I could do user.reload but I shouldn't have to hit the database to do this since the old values are stored in the state of the object.

Preferably a Rails 3 solution.

Answer 1

You could just loop through the 'changes' and reset them. There might be a method that does this, but I didn't look.

> c = Course.first
> c.name
=> "Athabasca Country Club"
> c.name = "Foo Bar"
=> "Foo Bar"
> c.changes
=> {"name"=>["Athabasca Country Club", "Foo Bar"]}
> c.changes.each {|k,vs| c[k] = vs.first}
> c.name
=> "Athabasca Country Club"

Actually looks like there is a "name_reset!" method you could call...

> c.changes.each {|k,vs| c.send("#{k}_reset!")}