objective c - iOS Facebook SDK SSO Safari log out -

i use latest facebook sdk in ios app.

it uses single sign on, after calling facebook logout method, when user log in again, dialog window saying logged in fine.

in other ios applications there logout button on safari web view, user can log out app.

my question how can implement such webview in application?

i know can use fbdialog instead of safari window control logout process need have possibility logout safari web view. may window logout button accessible in old versions of sdk?

i facing problem,there no default method logout facebook on safari when app under development,may safari show logout button when app goes live on app store