Why are all Rails helpers available to all views, all the time? Is there a way to disable this?

Question

Why can I access helper methods for one controller in the views for a different controller? Is there a way to disable this without hacking/patching Rails?

Answer 1

In Rails 3, actioncontroller/base.rb (around line 224):

def self.inherited(klass)
  super
  klass.helper :all if klass.superclass == ActionController::Base
end

So yes, if you derive your class from ActionController::Base, all helpers will be included.

To come around this, call clear_helpers (AbstractClass::Helpers; included in ActionController::Base) at the beginning of your controller's code. Source code comment for clear_helpers:

# Clears up all existing helpers in this class, only keeping the helper
# with the same name as this class.

E.g.:

class ApplicationController < ActionController::Base
  clear_helpers
  ...
end