Redirecting the user to the same page after login (Rails)

Question

I want to redirect the user to the same page after login. The scenario is that the user will be redirected to a signin page if he is not logged in. On the signin page, when he clicks on one of the available user options, I want to store the user_id and then redirect him back to the same page where he came from. For this, I'm using the following code:

In application_helper.rb:

module ApplicationHelper
def check_signed_in
if session[:user] == nil
  if request.format.html?
    session[:referer] = request.url
    redirect_to signin_index_path
  else
    @error = 'Please Signin!'
    @forward_page = '/signin'
    render 'signin/show_signin.js'
  end
end
end
end

In SigninController:

class SigninController < ApplicationController
def index
session[:user] = params[:user_id]
redirect_to session[:referer]
end 
end

In signin/index page:

We simulate a signin here. Click on an user and you will logged in as the selected user and you will be redirected the previous page.

<%= link_to 'Sam', controller:"signin", action: "index" , user_id: 284542812, remote: true %> <%= link_to 'Marge', controller:"signin", action: "index" , user_id: 604700687, remote: true %>

Error that I'm getting:

the user_id is not being saved and while redirecting I get an error saying that session[:referer] is nil.

Please explain what am I doing wrong

Answer 1

You are calling it async if request.format.html? then asking a format is html? it returns false. Since it returns false you are not able to store this session session[:referer] = request.url.

Also Rails has redirect_to :back option too. Try this below first, and let me know...

Helper:

module ApplicationHelper
  def check_signed_in
    if session[:user]
      session[:referer] = request.url
    end
  end
end

Controller:

class SigninController < ApplicationController
  include ApplicationHelper

  def index
    check_signed_in
    session[:user] = params[:user_id]
    redirect_to session[:referer]
  end 
end