Rails: Detecting User Session

In this episode we show you how to detect the user session so we can have the context of current_user in our application. We will then be able to use the context in our controller and views.

In the application_controller we'll implement the current_user method so we can access it from any other controller that inherits from it.

class ApplicationController < ActionController::Base  # ...    def current_user    User.where(id: session[:user_id]).first  end    # allows us to use the same method in the view  helper_method :current_userend

Now in the layout we'll render the email of the user.

# app/views/layouts/application.html.erb# ...<div id='main' class='container'>  # ...  <% if current_user %>    # if we have the user session    <%= current_user.email %>    <%= link_to 'Sign Out', sessions_path, method: :delete %>  <% else %>    # if we don't have the user session    <%= link_to 'Sign in', new_session_path %>    <%= link_to 'Sign up', new_user_path %>   <% end %>  <%= yield %></div>

View wise this should cover most of the functionality of the user authentication process.