Computing asset host in my Rails 3 models using compute_asset_host

helpers.rb

module Mynewsdesk
  module Helpers
    def self.compute_asset_host(path)
      host_config = Mynewsdesk::Application.config.asset_host
      if host_config.respond_to?(:call) && host_config.arity == 1
        host_config.call(path)
      else
        raise "Please set up config.asset_host with a proc that takes one argument"
      end
    end
  end
end