Question

I have used this method for logout facebook in app

- (void)fbDidLogout {
    // Remove saved authorization information if it exists
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    if ([defaults objectForKey:@"FBAccessTokenKey"]) {
        [defaults removeObjectForKey:@"FBAccessTokenKey"];
        [defaults removeObjectForKey:@"FBExpirationDateKey"];
        [defaults synchronize];
    }
    NSLog(@"logout success!");
}

This method has been invoked, but when I relaunch app the facebook still know about my latest authorization.

My full implementation

I create singleton object for facebook instance.

this is my manager .h

#import <Foundation/Foundation.h>
#import "FBConnect.h"

@interface FacebookManager : NSObject <FBSessionDelegate> {
    Facebook *facebook;
}
@property (nonatomic, strong) Facebook *facebook;

+ (FacebookManager *)sharedInstance;
- (void)initWithAppID:(NSString *)appID;

@end

this is singleton facebookmanager .m

#import "FacebookManager.h"

@implementation FacebookManager
@synthesize facebook;

static FacebookManager *_sharedInstance = nil;

+ (FacebookManager *)sharedInstance {
    @synchronized(self) {
        if (!_sharedInstance) {
            _sharedInstance = [[FacebookManager alloc] init];
        }
    }
    return _sharedInstance;
}

- (void)initWithAppID:(NSString *)appID {
    facebook = [[Facebook alloc] initWithAppId:appID andDelegate:self];
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    if ([defaults objectForKey:@"FBAccessTokenKey"]
        && [defaults objectForKey:@"FBExpirationDateKey"]) {
        facebook.accessToken = [defaults objectForKey:@"FBAccessTokenKey"];
        facebook.expirationDate = [defaults objectForKey:@"FBExpirationDateKey"];
    }
    if (![facebook isSessionValid]) {
        [facebook authorize:nil];
    }
}

- (void)fbDidLogout {
    // Remove saved authorization information if it exists
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    if ([defaults objectForKey:@"FBAccessTokenKey"]) {
        [defaults removeObjectForKey:@"FBAccessTokenKey"];
        [defaults removeObjectForKey:@"FBExpirationDateKey"];
        [defaults synchronize];
    }
    NSLog(@"logout success!");
}

@end

in appDelegate I make next:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{

    fbManager = [FacebookManager sharedInstance];
    [fbManager initWithAppID:@"myappid"];

... (some other code)

}

also add this code to app delegate:

- (BOOL)application:(UIApplication *)application handleOpenURL:(NSURL *)url {
    return [fbManager.facebook handleOpenURL:url]; 
}

- (void)fbDidLogin {
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    [defaults setObject:[fbManager.facebook accessToken] forKey:@"FBAccessTokenKey"];
    [defaults setObject:[fbManager.facebook expirationDate] forKey:@"FBExpirationDateKey"];
    [defaults synchronize];    
}

In other view controller I call this method for logout:

- (IBAction)logoutFacebook:(id)sender {
    FacebookManager *fbManager = [FacebookManager sharedInstance];
    [fbManager.facebook logout];
}

also in plist I have add needed url scheme.

Answer 1

That seems to be the way the ios sdk api with sso/oauth 2.0 works. I have not been able to logout completely even after clearing the tokens and I have not been able to switch users from the App. Got to go to the FB app to switch users

As a workaround, change the line in Facebook.m and disable the safariAuth

// [self authorizeWithFBAppAuth:YES safariAuth:YES];

 [self authorizeWithFBAppAuth:NO safariAuth:NO]

But then you have to type in the username and password everytime you authorize.