This is a well known topic, but i can't find the existing solution that will fully satisfy me. So i write it by myself :).
Assume we have a "single page" web site, that is talking with backend via REST API. Client side can be written with ember, angularjs or some like this. Backend - django rest framework (DRF). We've got a task - add social login (OAuth protocol).
How it will look like in case ...