inherited_resources - best practices for missing parent model - ruby

Question

Maybe you have seen/read the Railscast/Asciicast about subdomains in Rails 3. I'd like you to ask about best practices on how to implement an application behavior when the parent (in this article: "blog") is not found. Let me explain.
blog1.example.com/articles # it's normal situation
example.com/articles # abnormal situation.
In the second example no blog to find, but articles's routes are still available. I know, I can use something like this ...
def rescue_action(exception)
case exception
when ActiveRecord::RecordNotFound
return redirect_to blogs_path, :status => :moved_permanently
end
super
end
... but is it the "Rails way"? Any idea/comment on this?

Answer 1

What I did in this case, was to restrict the routing based on subdomain or no subdomain. In that case, you can easily have routes that only work on subdomains, resulting in a routing error (404) if someone tries to access that same route without a subdomain.
So for example:
routes.rb
Backend::Application.routes.draw do
constraints AppDomainRoutes.new do
# signup paths
get "/signup" => "accounts#new", as: "signup"
post "/signup" => "accounts#create", as: "signup"
# root
root to: "accounts#new"
end
constraints AccountDomainRoutes.new do
# password reset paths
get "/reset_password/:password_reset_token" => "reset_passwords#edit", as: "reset_user_password"
put "/reset_password/:password_reset_token" => "reset_passwords#update", as: "reset_user_password"
# websites
resources :websites
# root
root to: "websites#new"
end
# request password reset paths
get "/reset_password" => "reset_passwords#new", as: "reset_password_request"
post "/reset_password" => "reset_passwords#create", as: "reset_password_request"
# login paths
get "/login" => "sessions#new", as: "login"
post "/login" => "sessions#create", as: "login"
# logout paths
get "/logout" => "sessions#destroy", as: "logout"
delete "/logout" => "sessions#destroy", as: "logout"
end
And then in lib/routes:
app_domain_routes.rb
class AppDomainRoutes
def matches?(request)
request.subdomain.blank? || request.subdomain == "www"
end
end
account_domain_routes.rb
class AccountDomainRoutes
def matches?(request)
request.subdomain.present? && request.subdomain != "www"
end
end
Now, /signup is only accessible from the main application domain www.mydomain.com or mydomain.com and /websites/new is only accessible from *.mydomain.com. But /login is still accessible in both situations, for convenience sake.
Obviously this doesn't solve the issue of visiting invalid.mydomain.com when invalid in fact is not an account in the database.
For this you go back to the application_controller.rb and handle redirection there, like this:
application_controller.rb
class ApplicationController < ActionController::Base
protect_from_forgery
before_filter :redirect_unknown_account
private
# returns current subdomain (account.subdomain) or nil
def account_subdomain
#account_subdomain ||= request.subdomain if request.subdomain.present? && request.subdomain != "www"
end
def current_account
#current_account ||= Account.find_by_username(account_subdomain) if account_subdomain
end
def redirect_unknown_account
if account_subdomain && ! current_account
redirect_to signup_url(host: app_domain), alert: "This account does not exist."
end
end
def account_domain
#account_domain ||= "#{current_account.username}.#{app_domain}" if current_account
end
def app_domain
#app_domain ||= "mydomain.com"
end
end