Restore view context patching to Action Mailer

[rf-]

The main change here is moving the view context patching back into Draper::System.setup, which makes Draper work properly in Action Mailer again.

I also removed a couple of view_context calls that aren't necessary anymore. There may be others, but by inspection it looks like all of the remaining calls are actually necessary.

[travisbot]

This pull request passes (merged 75a8204 into c54341c).

[rf-]

A side note: why does Draper now depend on Rails 3.2? Is there really anything in there that won't work with 3.1?

[steveklabnik]

why does Draper now depend on Rails 3.2?

Rails 3.2 is the only supported version by the Rails team. And therefore, the only version I officially support with Draper. I don't remember if it's a hard dependency or not, to be honest. 3.1.x is security fixes only.

[steveklabnik]

Thanks for doing this work, by the way. :)

[rf-]

Thanks for doing this work, by the way. :)

No problem.

Rails 3.2 is the only supported version by the Rails team. And therefore, the only version I officially support with Draper.

This is a weird conflation of two different meanings of the word "support". You can allow people to install Draper on Rails 3.1 without signing a binding contract that you'll personally fix any problem anyone ever has with it.

I don't remember if it's a hard dependency or not, to be honest.

It is a hard dependency.

[steveklabnik]

I didn't mean hard as in the gemfile, I meant hard as in "I don't remember if I'm relying on any 3.2 behavior."

Maybe it's just me, but if I saw ~> 3.1 in a Gemfile, i'd assume that 3.1 is supported by the author. If someone wants to run Draper with Rails 3.1, they can really easily do this in combination with `gem "draper", :github => "foo/draper" and run it on whatever they'd like.