I use devise and cancan
class PostsController < ApplicationController
before_filter :authenticate_user!, only: [:create, :update, :destroy]
so an unauthentificate user can access new post form. Now when unauthentificate user submit new or edit forms, he is redirected to login form. But when he logs in, his post is not save in database. Is there anythings to do such as callback if I want the post to be saved ?