Question

I am working through the rails tutorial (railstutorial.org) and noticed an issue with the sign in form when a validation occurs. My route for this action is:

match '/signin',  to: 'sessions#new'

When a validation occurs the URL for the page switches to /sessions. My controller for sessions looks like this:

class SessionsController < ApplicationController

  def new
  end

  def create
    user = User.find_by_email(params[:session][:email])
    if user && user.authenticate(params[:session][:password])
      sign_in user
      redirect_back_or user
    else
      flash.now[:error] = "Invalid email/password combination"
      render 'new'
    end
  end

My question is how to have this validated form still appear with the url of /signin. Thank you.

Answer 1

If you want to keep using restful routing (which is the current and long time standard for Rails), you can’t. If you don’t mind deviating from this path you can create some custom routes instead of using the “normal” resource-style routing.

First you have to change your controller and move the sign in actions from the create method to the new method (which is what /signin routes to):

class SessionsController < ApplicationController
  def new
    if request.post?
      user = User.find_by_email(params[:session][:email])
      if user && user.authenticate(params[:session][:password])
        sign_in user
        redirect_back_or user
      else
        flash.now[:error] = "Invalid email/password combination"
      end
    end
  end
end

This means both the initial GET /signin request and the eventual POST /signin requests will get handled by the same action. If a POST was detected it will try to log in the user and redirect on success. If a GET request was made it will simply render the form as normal.

Then you have to change your login form (app/views/sessions/new.html.erb) to use the signin path instead of the normal route:

<% form_tag '/signin' do %>
  ....
<% end -%>

That should do it.