Get long live access token from Facebook

As I understand it, recently Facebook has decided to remove the offline_access permission and has introduced a concept called long-lived access tokens which last a maximum of 60 days. Is there anyone who knows how to get this access token with the Facebook JavaScript SDK?

Solution

There is a way to extend this to 60 days. described here: https://developers.facebook.com/docs/roadmap/completed-changes/offline-access-removal/ under Scenario 4: Client-side OAuth and Extending Access_Token Expiration Time through New Endpoint

Edit: In order to extend the access token you need to make the following request with your short lived access token:

https://graph.facebook.com/oauth/access_token?             
    client_id=APP_ID&
    client_secret=APP_SECRET&
    grant_type=fb_exchange_token&
    fb_exchange_token=EXISTING_ACCESS_TOKEN