Rails namespace admin on custom subdomain

Question

My rails app is set to use subdomains as described in this RailsCast:

http://railscasts.com/episodes/221-subdomains-in-rails-3

Now, I would like to add an ad

Answer 1

I was able to solve this, although it feels a little hackish. Understanding that Rails treats constraints either true or false, I set another constraint inside the initial subdomain constraint check. It splits the subdomain in 2 and examines the first subdomain to see if it equals "admin". If true, it routes to the admin/controllers and admin/views (because of module: "admin"), if not, it routes to the less specific routes that are not inside the "admin" module.

At first I didn't have the namespace :admin, and my route helpers were incorrect (the admin routes weren't prefixed with "admin" and the less specific routes weren't being set since they were duplicates). Once I added namespace :admin and the path: "" (this is important, too, because it removes "admin/" from the URI Pattern), it worked!

One last thing, in the admin/controllers, you have to edit the set_blog method, since "admin.company" is being interpreted instead (see admin/blogs_controller.rb).

routes.rb

Blog::Application.routes.draw do
  constraints(Subdomain) do
    namespace :admin, module: "admin", path: "", constraints: lamda { |r| r.subdomain.split('.')[0] == 'admin' } do
      match '/', to: 'blogs#show', via: 'get'
      ...
    end

    match '/', to: 'blogs#show', via: 'get'
    ...
  end
  ...
end

Rake Routes:

Prefix Verb URI Pattern Controller#Action
 admin GET  /   admin/blogs#show
 ...

​ GET / blogs#show ...

admin/blogs_controller.rb

BlogController < ApplicationController
  before_action :set_blog
  ...
  private
    set_blog
      @blog = Blog.find_by_subdomain!(request.subdomain.split('.')[1])
    end
end

Let me know if there's anything cleaner out there, if not, hopefully this helps others with this issue.