How to use url helpers in lib modules, and set host for multiple environments

Question

In a Rails 3.2 app I need to access url_helpers in a lib file. I\'m using

Rails.application.routes.url_helpers.model_url(model)

<

Answer 1

This is a problem that I keep running into and has bugged me for a while.

I know many will say it goes against the MVC architecture to access url_helpers in models and modules, but there are times—such as when interfacing with an external API—where it does make sense.

And now thanks to this great blog post I've found an answer!

#lib/routing.rb

module Routing
  extend ActiveSupport::Concern
  include Rails.application.routes.url_helpers

  included do
    def default_url_options
      ActionMailer::Base.default_url_options
    end
  end
end

#lib/url_generator.rb

class UrlGenerator
  include Routing
end

I can now call the following in any model, module, class, console, etc

UrlGenerator.new.models_url

Result!