Add note about upgrading custom routes from put to patch.

[javan]

I assume this is expected behavior and not a bug?

[carlosantoniodasilva]

Hm I'm afraid this wasn't intentional, it should be accepting both put and patch verbs interchangeably. At least that was the original idea of introducing patch as far as I know, so we may need to review it to see if we aren't missing some place that needs fixing. Thanks!

[steveklabnik]

Yeah, this feels like an accident.

[javan]

Aha! I suspect this was introduced somewhere in between 4.0.0.beta1 and 4.0.0.rc1. At least that's when we noticed it in Basecamp.

[trevorturk]

I'm digging into this a bit more...

I don't think it was caused by the 4.0.0.beta1 -> 4.0.0.rc1 upgrade, I think we just didn't notice the bug right away.

I think the change came from this commit: b7a0945 /cc @fxn

I made a test app here to isolate the commit: https://github.com/trevorturk/rails-issue-patch

According to this blog post we want to continue supporting PUT routes: http://weblog.rubyonrails.org/2012/2/25/edge-rails-patch-is-the-new-primary-http-method-for-updates/

Perhaps this should be added to the Rails 4.0.0 milestone? It's a potential blocker for release. Perhaps it's worth considering making this a breaking change in the upgrade from 3.x?

I'll dig some more to see if I can fix the issue, but I'm not 100% sure how to proceed. If we see a PUT route with no conflicting PATCH route, should we make one? (I haven't thought through all of the potential areas of conflict yet.)

[trevorturk]

Another option would be to undo some of b7a0945. We could set default_method_for_update to put by default, but generate new apps with it set to patch to make the change opt-in for existing apps and set by default for new apps like ye olde new_rails_defaults did.

[trevorturk]

If we decide to leave things as-is, another possible note for the upgrade guide would be suggesting an alternative workaround. You can force form_for to use put instead of patch if, for example, you didn't want to upgrade your routes to avoid breaking API clients:

# Rails 3
<%= form_for [ :update_name, @user ] do |f| %>

# Rails 4
<%= form_for [ :update_name, @user ], method: :put do |f| %>

[dhh]

We've gone with PATCH, so I think we should stick to it and document the issue. Applying this. Please add further doc changes if necessary to make this clear.