Question

Is there a way to fetch cached access token through FBSession using Facebook SDK if the user is logged in native Facebook.

I am trying to implement autologin through Facebook in an app i.e.when a user is logged in native Facebook then the app should not ask for the login and user should get automatically logged in.

I have used FBSession and FBTokenCacheStrategy and the user is getting logged in automatically but I am not able to fetch the access token which I need to call some API. The following code I am using to get this done :

CacheToken = [[FBTokenCache alloc]init];
NSArray *permissions = [[NSArray alloc]initWithObjects:@"email,user_photos,user_videos,publish_stream,offline_access,user_checkins,friends_checkins", nil];


self.fbsession = [[FBSession alloc] initWithAppID:@"484473011575776"
                                              permissions:permissions
                                          urlSchemeSuffix:nil
                                       tokenCacheStrategy:CacheToken];

(fbsession is the object of Facebook SDK class FBSession)
[FBSession setActiveSession:self.fbsession];


[FBSession openActiveSessionWithReadPermissions:permissions
                                                   allowLoginUI:YES
                                              completionHandler:^(FBSession *session, FBSessionState state, NSError *error) {
                                                  [self sessionStateChanged:session state:state error:error];

Thanks in advance.

Answer 1

To get the access token you should use this:
[FBSession activeSession] accessToken]

However, it seems like you want to check whether there is already a (cached) access token. To do this you can do this:

// See if we have a valid token for the current state.
if (FBSession.activeSession.state == FBSessionStateCreatedTokenLoaded) {
    NSLog(@"The value access token is: %@", [[FBSession activeSession] accessToken]);
} else { 
    // No, display the login page.
}

Make sure also to do this in your app delegate or the access token will be nil:

- (BOOL)application:(UIApplication *)application openURL:(NSURL *)url sourceApplication:(NSString *)sourceApplication annotation:(id)annotation
{
    return [FBSession.activeSession handleOpenURL:url];
}

- (void)applicationDidBecomeActive:(UIApplication *)application
{
// We need to properly handle activation of the application with regards to Facebook Login
    // (e.g., returning from iOS 6.0 Login Dialog or from fast app switching).
    [FBSession.activeSession handleDidBecomeActive];
}

Hope this helps