Currently I am learning node.js, passport.js and angular.js, the main idea is to have an overall concept of how is working the full stack javascript.
I implemented local strategies for sign-in or log in and I want to do some examples with facebook and twitter oauth. I saw that there is a callback before the authentication but I'm not sure how I can implement this in a single page application. I can return to the root path in nodejs but how Angular can know if the user is logged in or not?