iOS GCM error code 501

Question

Recently I start to get this error code whenever I try to use the GCM apis in my iOS app: Error Domain=com.google.gcm Code=501 \"(null)\"

I couldn\'t find the meanin

Answer 1

if you are been developing using this sample

https://github.com/googlesamples/google-services/blob/master/ios/gcm/GcmExample/

than you have to know, it is quite poor and wrong in some points

to fix the error above (you did request the [[GGLInstanceID sharedInstance] tokenWithAuthorizedEntity successfully, but still that error pops up), you have to call ALSO [[GGLInstanceID sharedInstance] startWithConfig: before calling the [[GCMService sharedInstance] connectWithHandler:

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

    NSError* configureError;
    [[GGLContext sharedInstance] configureWithError:&configureError];

    if (configureError) {
        NSLog(@"Error configuring Google services: %@", configureError);
    }

    GCMConfig *gcmConfig = [GCMConfig defaultConfig];
    gcmConfig.receiverDelegate = self;
    [[GCMService sharedInstance] startWithConfig:gcmConfig];

    // add this
    {
        GGLInstanceIDConfig *instanceIDConfig = [GGLInstanceIDConfig defaultConfig];
        instanceIDConfig.delegate = self;

        [[GGLInstanceID sharedInstance] startWithConfig:instanceIDConfig];
    }

    ...
    [self requestAndSynchronizeGCMTokenIfNeeded];
    ...

    return YES;
}

BUT remember, you will always get the error, when the [[GGLInstanceID sharedInstance] tokenWithAuthorizedEntity: did not complete, so you should add a chcek for that in the applicationDidBecomeActive smth. like

- (void)applicationDidBecomeActive:(UIApplication *)application {

    if (self.data.deviceToken) {

        [[GCMService sharedInstance] connectWithHandler:^(NSError *error) {

            if (error) {

                NSLog(@"Could not connect to GCM: %@", error.localizedDescription);

            } else {

                self.connectedToGCM = YES;
                NSLog(@"Connected to GCM");

                [self subscribeToTopic];

            }

        }];

    }

}

and the last thing, you should try to connect in the handler block of tokenWithAuthorizedEntity: as it is sometimes called before the token is recaived and therefore ending in error

[[GGLInstanceID sharedInstance] tokenWithAuthorizedEntity:gcmSenderID scope:kGGLInstanceIDScopeGCM options:options handler:^(NSString *token, NSError *error) {
  // connect to GCM also here ([[GCMService sharedInstance] connectWithHandler:)
}

Answer 2

The error occurred because I was calling

GCMService.sharedInstance().connectWithHandler() { error in  if(error != nil) {   print(error) } } 

before I had received a registration token, or had failed to refresh my token.

"Error Domain=com.google.gcm Code=501 "(null)" " is a really bad error message.