This document says 'Users will never see this dialog, it's specific to the Explorer, but it brings up two important things. First, the permissions that your application needs are requested at authorization time. This is important because it means that your application will need to request a full set of permissions up front for everything it might want to do.
' But elsewhere in the docs (e.g. https://developers.facebook.com/docs/technical-guides/ ) we say to only ask for permissions before they're needed ; Also the iOS login dialog enforces asking for read and write separately