Custom URL helpers in Rails

Ever want a named route for something that's not necessarily a resource in your Rails app?

In your any of your route files you can utilize direct.

# config/routes.rb

Rails.application.routes.draw do
  get 'foo', to: 'foo#bar'

  direct :get_to_the_goog do
    "https://google.com"
  end
end

This gives a nice named route of get_to_the_goog_url!

This can be even more useful as the return value of the block has to be valid arguments that you would pass to url_for. So you can use pretty much anything you'd normally use to build a url helper.

Let's modify this just a bit to be more useful.

# config/routes.rb

Rails.application.routes.draw do
  get 'foo', to: 'foo#bar'

  direct :get_to_the_goog, search: nil do |options|
    "https://google.com/search?q=#{options[:search]}"
  end
end

Now we can call get_to_the_goog_url(search: "TIL").

Pretty cool... just take note of a few caveats. You get access to the _path version of the named helper but even if the helper is using a hard coded string (like our example above), it will remove the domain info (rightfully so). Also you are not able to use the direct functionality inside of a namespace or scope, however it will raise an error if you do... so that's nice.