#user_locale shall be private

[tmaier]

Only actions shall be public methods of ApplicationController. (see http://api.rubyonrails.org/classes/ActionController/Base.html)

I used to have #user_locale as a private method.

Now I get the following error message: private methoduser_locale' called for FooController`

[mateomurphy]

Having only actions be public methods is more of a best practice than an obligation (and that's only mentioned in the guides, not the documentation you linked). It's still a good practice though, so I will fix this shortly.