The sync callback is invoked first on a canvas page, in which case we
require the user to add the application. Later the user will be redirected
to this callback on the locale server, with an token that allows us to
write the necessary row to the…
Wrapper function for fb_api_init. This helps for functions that should
work whether or not we are on a canvas page. For canvas pages, the active
fb object is used. For non-canvas pages, it will initialize the API using
an infinite session, if…