What does this mean: +[UAirship executeUnsafeTakeOff:]?

Question

I am trying to setup push notifications using Urban Airship and I believe I'm having a problem with the provisioning profiles or ssl certificates. The app is not prompting the user for Push Notifications permissions but I am not getting a 'no valid "aps-environment" entitlement string found for application' message, and I can see the aps-environment entitlement in the .mobileprovision.

I can't find any documentation on +[UAirship executeUnsafeTakeOff:] so I am wondering if anyone knows what that could mean?

Also, the device token is being returned as nil, as logged by Urban Airship:

[D] -[UAPush updateRegistrationForcefully:] [Line 544] Device token is nil. Registration will be attempted at a later time

There is no Urban Airship code running prior to the [UAirship takeOff:config] call, and the app does not crash as a result of the error.

Answer 1

Without knowing much about Urban Airship I can offer a guess.

takeOff ensures that the actual implementation provided in executeUnsafeTakeoff only happens once. It makes sure that the current thread is the main thread and then ensures that it only happens once.

Therefore getting an executeUnsafeTakeoff error really only tells you that something went wrong, such as if the configfailed tovalidate` (see below).

You need to make sure that the app can receive push notifications, as you mentioned.

Here is takeOff:

+ (void)takeOff {
    [UAirship takeOff:[UAConfig defaultConfig]];
}

+ (void)takeOff:(UAConfig *)config {

    // takeOff needs to be run on the main thread
    if (![[NSThread currentThread] isMainThread]) {
        NSException *mainThreadException = [NSException exceptionWithName:UAirshipTakeOffBackgroundThreadException
                                                                   reason:@"UAirship takeOff must be called on the main thread."
                                                                 userInfo:nil];
        [mainThreadException raise];
    }

    dispatch_once(&takeOffPred_, ^{
        [UAirship executeUnsafeTakeOff:config];
    });
}

Here is executeUnsafeTakeoff:

/*
 * This is an unsafe version of takeOff - use takeOff: instead for dispatch_once
 */
+ (void)executeUnsafeTakeOff:(UAConfig *)config {
    // Airships only take off once!
    if (_sharedAirship) {
        return;
    }

    [UAirship setLogLevel:config.logLevel];

    _sharedAirship = [[UAirship alloc] init];
    _sharedAirship.config = config;

    // Ensure that app credentials have been passed in
    if (![config validate]) {

        UA_LERR(@"The AirshipConfig.plist file is missing and no application credentials were specified at runtime.");

        // Bail now. Don't continue the takeOff sequence.
        return;
    }

    UA_LINFO(@"App Key: %@", _sharedAirship.config.appKey);
    UA_LINFO(@"App Secret: %@", _sharedAirship.config.appSecret);
    UA_LINFO(@"Server: %@", _sharedAirship.config.deviceAPIURL);

    if (config.automaticSetupEnabled) {

        _sharedAirship.appDelegate = [[UAAppDelegateProxy alloc ]init];

        //swap pointers with the initial app delegate
        @synchronized ([UIApplication sharedApplication]) {
            _sharedAirship.appDelegate.originalAppDelegate = [UIApplication sharedApplication].delegate;
            _sharedAirship.appDelegate.airshipAppDelegate = [[UAAppDelegate alloc] init];
            [UIApplication sharedApplication].delegate = _sharedAirship.appDelegate;
        }
    }


    // Build a custom user agent with the app key and name
    [_sharedAirship configureUserAgent];

    // Set up analytics
    _sharedAirship.analytics = [[UAAnalytics alloc] initWithConfig:_sharedAirship.config];
    [_sharedAirship.analytics delayNextSend:UAAnalyticsFirstBatchUploadInterval];

    /*
     * Handle Debug Options
     */

    //For testing, set this value in AirshipConfig to clear out
    //the keychain credentials, as they will otherwise be persisted
    //even when the application is uninstalled.
    if (config.clearKeychain) {

        UA_LDEBUG(@"Deleting the keychain credentials");
        [UAKeychainUtils deleteKeychainValue:_sharedAirship.config.appKey];

        UA_LDEBUG(@"Deleting the UA device ID");
        [UAKeychainUtils deleteKeychainValue:kUAKeychainDeviceIDKey];
    }

    if (!config.inProduction) {
        [_sharedAirship validate];
    }

    if (config.cacheDiskSizeInMB > 0) {
        UA_LINFO("Registering UAURLProtocol");
        [NSURLProtocol registerClass:[UAURLProtocol class]];
    }

    // The singleton is now ready for use!
    _sharedAirship.ready = true;


    //create/setup user (begin listening for device token changes)
    [[UAUser defaultUser] initializeUser];

}