title: Way to design user permission check
body: <p>I am new to this codeigniter. I am building a application where in user roles play a important role. In a controller i want to check if user has a particular role or permission and then give access to functions. I was wondering if i can create a flow such that i don't need to check permissions or roles for each controller, when extending only this can be done. Can i do so? </p>
  
  <p>/** Update **/</p>
  
  <p>How will i do if i want to set permissions for each method in a controller or only some methods in a controller.</p>