ActiveSupport::CurrentAttributes

What is Active Support?

Active Support is the Ruby on Rails component responsible for providing Ruby language extensions, utilities, and other transversal stuff.

What is ActiveSupport::CurrentAttributes

Abstract super class that provides a thread-isolated attributes singleton, which resets automatically before and after each request. This allows you to keep all the per-request attributes easily available to the whole system.

How to use it in your Rails APP?

first in your application_controller define a method called set_current_user. we put this method in application controller because all other controllers inhert from it

class ApplicationController < ActionController::Base
before_action :set_current_user
 def set_current_user
  if session[:user_id]
   Current.user = User.find_by[id: session[:user_id]
  end
 end
end

before_action method in rails means before you run any actions in other controllers call first ‘set_current_user’ method. When you make request in your rails app ‘set_current_user’ method will check if the Current.user = nil (means user not logged in) or Current.user = “hashed string” (means user is logged in).

after that in app/model define Current model

class Current < ActiveSupport::CurrentAttributes
 attribute :user
end

If you do not want to use ActiveSupport::CurrentAttributes class to check if user already logged in or not you can do the following in your Application controller

class ApplicationController < ActionController::Base   
 
  def home        
   if logged_in?            
    redirect_to user_path(current_user)         
   end    
  end     
 def current_user        
  @current_user ||= User.find(session[:user_id]) 
   if session[:user_id]    
 end        
 def logged_in?       
  !!current_user    
 end     
 def authenticate_user        
   if !logged_in?          
    redirect_to '/'        
   end      
 end
end

That’s all thank you for reading check out some of the cool functionality provided to you By Active Support

Active Support Core Extensions - Ruby on Rails Guides

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