Provide the ability to refresh access token

[anderscheow]

The token may expired, the native SDK provide the ability to refresh token. Please expose the method.

[hkakutalua]

Is there some progress related to this?

[hairen]

@anderscheow @Henry-Keys As this plugin depends on FB Login SDK, token is refreshed once per day. I think we can regarded it as time-unlimited token.

[cubuspl42]

@hairen Have you actually seen the token provided by flutter_facebook_login to extend?

The documentation is misleading. If I understand correctly, the native SDK doesn't actually automatically refresh the token.

[cubuspl42]

See my answer on StackOverflow.