Question

I’m trying to implement a login form, but my routing seems to be wrong.
When the authentication fails, the app redirects to subdomain.domain.com/login but it should only render the login page again (only subdomain.domain.com without “/login”).

views/login/index.html

<%= form_tag(check_login_path, :method => "post")  do %>
    ... form fields
<% end %>

routes.rb

constraints(Subdomain) do
  match '/' => 'login#index', :as => :login
  match '/login' => 'login#check', :as => :check_login
  match '/dashboard' => 'dashboard#index', :as => :dashboard    
end

login_controller.rb

class LoginController < ApplicationController

  def index
      # some index logic
  end

  def check

    # authenticate with mite.yo.lk account login

    Mite.account = params[:domain]
    Mite.authenticate(params[:email], params[:password])
    if Mite.validate
      redirect_to dashboard_path
    else
      flash[:error] = "not valid"
      render :template => 'login/index'
    end
  end

end

Answer 1

In your routes, you are routing ‘/login’ to the check action, and then in that action you are rendering a template for a failed validation. Rendering does not change the URL, which is why you end up with the url ‘/login’.

If you want the user to see the root url after a failed login attempt, then you’ll need to change the render to a redirect_to :index:

if Mite.validate
  redirect_to dashboard_path
else
  flash[:error] = "not valid"
  redirect_to :index
end

Alternatively, you could replace your check_login path to use the root url with a POST request, and make your login path route to the root only for a GET request, like so:

constraints(Subdomain) do
  get '/' => 'login#index', :as => :login
  post '/' => 'login#check', :as => :check_login
  match '/dashboard' => 'dashboard#index', :as => :dashboard    
end

If you do this, then you should be able to leave your current controller code as is and get the result you want.