module AbstractController::Helpers::ClassMethods

def modules_for_helpers(args)

helpers provided.
* Array - A normalized list of modules for the list of
==== Returns

* args - An array of helpers
==== Parameters

are returned.
After loading the appropriate files, the corresponding modules

Module:: No further processing

and "foo_bar_helper.rb" is loaded using require_dependency.
String or Symbol:: :FooBar or "FooBar" becomes "foo_bar_helper",

helpers with the following behavior:
Returns a list of modules, normalized from the acceptable kinds of 
def modules_for_helpers(args)
  args.flatten.map! do |arg|
    case arg
    when String, Symbol
      file_name = "#{arg.to_s.underscore}_helper"
      begin
        require_dependency(file_name)
      rescue LoadError => e
        raise AbstractController::Helpers::MissingHelperError.new(e, file_name)
      end
      mod_name = file_name.camelize
      begin
        mod_name.constantize
      rescue LoadError
        # dependencies.rb gives a similar error message but its wording is
        # not as clear because it mentions autoloading. To the user all it
        # matters is that a helper module couldn't be loaded, autoloading
        # is an internal mechanism that should not leak.
        raise NameError, "Couldn't find #{mod_name}, expected it to be defined in helpers/#{file_name}.rb"
      end
    when Module
      arg
    else
      raise ArgumentError, "helper must be a String, Symbol, or Module"
    end
  end
end