Why is `layout nil` not working?

Question

I just upgraded my Rails site from Rails 2 to Rails 3.2.

On my old controller I had:

class Foo::BarController < ApplicationController
   layout nil 
   ... 
end

However now that I upgraded to Rails 3 it seems I need to change that to:

layout false

The documentation on Rails Guides claims that layout nil should work fine:

Layout declarations cascade downward in the hierarchy ...

class OldPostsController < SpecialPostsController
layout nil

I have the following relevant gems in my Gemfile.lock

GEM

actionpack (3.2.6)
  activemodel (= 3.2.6)
  activesupport (= 3.2.6)
  builder (~> 3.0.0)
  erubis (~> 2.7.0)
builder (3.0.0)
erubis (2.7.0)
haml (3.1.6)

jquery-rails (2.0.2)
  railties (>= 3.2.0, < 5.0)

Is this a documented change somewhere, or is it a related gem monkey patching something?

Answer 1

The API explains it like this:

If the specified layout is:

• a string: the string is the template name
• a symbol: call the method specified by the symbol, which will return the template name
• false: there is no layout
• true: raise an ArgumentError
• nil: force default layout behavior with inheritance

So the meaning of nil changed from no layout to "force default layout behavior with inheritance". Seems the explanation in Rails Guides is incorrect.