How to Display the Facebook login page when button is clicked - ios

Question

I want to display display the Facebook login page in my app when the user is not signed-in yet. I'm using Facebook SDK for posting a status message on the users Facebook wall when the user allows the app.
Heres the code:
if (FBSession.activeSession.isOpen) {
// post to wall
#try {
[self postStatusMethod];
[self dismissViewControllerAnimated:YES completion:nil];
}
#catch (NSException *exception) {
NSLog(#"Error on posting to fb: %#", exception);
}
#finally {
}
} else {
// try to open session with existing valid token
NSArray *permissions = [[NSArray alloc] initWithObjects:
#"read_stream",
#"publish_actions",
nil];
FBSession *session = [[FBSession alloc] initWithPermissions:permissions];
[FBSession setActiveSession:session];
if([FBSession openActiveSessionWithAllowLoginUI:NO]) {
// post to wall
#try {
[self postStatusMethod];
[self dismissViewControllerAnimated:YES completion:nil];
}
#catch (NSException *exception) {
NSLog(#"Error on posting to fb: %#", exception);
}
#finally {
}
} else {
// you need to log the user
[self userLogin];
}
}
how do i create the userLogin function so that is will display this:
Then, go back to the same view controller. i am using Facebook sdk.

Answer 1

Finally, i build the code:
-(void) userLogin {
NSLog(#"Clicked!");
// If the session state is any of the two "open" states when the button is clicked
if (FBSession.activeSession.state == FBSessionStateOpen
|| FBSession.activeSession.state == FBSessionStateOpenTokenExtended) {
// Close the session and remove the access token from the cache
// The session state handler (in the app delegate) will be called automatically
[FBSession.activeSession closeAndClearTokenInformation];
// If the session state is not any of the two "open" states when the button is clicked
} else {
// Open a session showing the user the login UI
// You must ALWAYS ask for public_profile permissions when opening a session
[FBSession openActiveSessionWithReadPermissions:#[#"public_profile"]
allowLoginUI:YES
completionHandler:
^(FBSession *session, FBSessionState state, NSError *error) {
}];
}
}
But it goes back to my main menu not on the same menu where i click it.