If we are using Devise gem with our Rails project, One of the common tasks that a developer wants to do is to show a custom page when a user signed in .

So here our intention is to modify the default Devise's behaviour when a user signed in .

Let's consider the following code in application_controller.rb.

class ApplicationController < ActionController::Base

  protect_from_forgery with: :exception

  before_action :authenticate_user!
 
  def after_sign_in_path_for(current_user)
    profile_path
  end
   
  

end

 Here is the routes.rb file :

Rails.application.routes.draw do
  
   
  get 'profile' => 'users#profile'
 

end

Here after_sign_in_path_for  method simply renders profile page after a successful login. Similarly after_sign_out_path_for method renders the intended custom page after a successful log out. Below are the excerpts from the application_controller.rb and config/routes.rb respectively:

  def after_sign_out_path_for(resource_or_scope)
    root_path
  end

 root 'homes#index'

So ,here after log out a user will be on the root page of the application.

One most important thing is  after_sign_out_path_for  method  accepts a symbol with the scope, and not the resource .