GCM Notifications not receiving when app is in background mode in iOS

Question

I have configured GCM in my existing app and i am receiving the notifications there. Now i am facing two problem: 1) I am not receiving notifications When i exit the application or application is in the background. 2) I am not receiving notification in iphone's notification area, only when my app is running i only direct receive alert message there. And when i pull down notification area i get this message in xcode's console "Could not connect to GCM: The operation couldn’t be completed. (com.google.gcm error 2001.)"

My PHP file is below

<?php

// Payload data you want to send to iOSdevice(s)
// (it will be accessible via intent extras)    
$data = array( 'message' => 'Hello World!');

// The recipient registration tokens for this notification
// http://developer.android.com/google/gcm/ 
$ids = array( 'kucy6xoUmx********eeRsla' );

// Send a GCM push
sendGoogleCloudMessage(  $data, $ids );

function sendGoogleCloudMessage( $data, $ids )
{
    // Insert real GCM API key from Google APIs Console
    // https://code.google.com/apis/console/        
    $apiKey = 'AIz******9JA';

    // Define URL to GCM endpoint
    $url = 'https://gcm-http.googleapis.com/gcm/send';

    // Set GCM post variables (device IDs and push payload)     
    $post = array(
                    'registration_ids'  => $ids,
                    'data'              => $data,                   
                    );

    // Set CURL request headers (authentication and type)       
    $headers = array( 
                        'Authorization: key=' . $apiKey,
                        'Content-Type: application/json'
                    );

    // Initialize curl handle       
    $ch = curl_init();

    // Set URL to GCM endpoint      
    curl_setopt( $ch, CURLOPT_URL, $url );

    // Set request method to POST       
    curl_setopt( $ch, CURLOPT_POST, true );

    // Set our custom headers       
    curl_setopt( $ch, CURLOPT_HTTPHEADER, $headers );

    // Get the response back as string instead of printing it       
    curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true );

    // Set JSON post data
    curl_setopt( $ch, CURLOPT_POSTFIELDS, json_encode( $post ) );

    // Actually send the push   
    $result = curl_exec( $ch );

    // Error handling
    if ( curl_errno( $ch ) )
    {
        echo 'GCM error: ' . curl_error( $ch );
    }

    // Close curl handle
    curl_close( $ch );

    // Debug GCM response       
    echo $result;
}

?>

Here is my AppDelegate.m file

// [START register_for_remote_notifications]
- (BOOL)application:(UIApplication *)application
didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // [START_EXCLUDE]
    _registrationKey = @"onRegistrationCompleted";
    _messageKey = @"onMessageReceived";
    // Configure the Google context: parses the GoogleService-Info.plist, and initializes
    // the services that have entries in the file
    NSError* configureError;
    [[GGLContext sharedInstance] configureWithError:&configureError];
    NSAssert(!configureError, @"Error configuring Google services: %@", configureError);
    _gcmSenderID = [[[GGLContext sharedInstance] configuration] gcmSenderID];
    // Register for remote notifications
    if (floor(NSFoundationVersionNumber) <= NSFoundationVersionNumber_iOS_7_1) {
        // iOS 7.1 or earlier
        UIRemoteNotificationType allNotificationTypes =
        (UIRemoteNotificationTypeSound | UIRemoteNotificationTypeAlert | UIRemoteNotificationTypeBadge);
        [application registerForRemoteNotificationTypes:allNotificationTypes];
    } else {
        // iOS 8 or later
        // [END_EXCLUDE]
        UIUserNotificationType allNotificationTypes =
        (UIUserNotificationTypeSound | UIUserNotificationTypeAlert | UIUserNotificationTypeBadge);
        UIUserNotificationSettings *settings =
        [UIUserNotificationSettings settingsForTypes:allNotificationTypes categories:nil];
        [[UIApplication sharedApplication] registerUserNotificationSettings:settings];
        [[UIApplication sharedApplication] registerForRemoteNotifications];
    }
    // [END register_for_remote_notifications]
    // [START start_gcm_service]
    GCMConfig *gcmConfig = [GCMConfig defaultConfig];
    gcmConfig.receiverDelegate = self;
    [[GCMService sharedInstance] startWithConfig:gcmConfig];
    // [END start_gcm_service]
    __weak typeof(self) weakSelf = self;
    // Handler for registration token request
    _registrationHandler = ^(NSString *registrationToken, NSError *error){
        if (registrationToken != nil) {
            weakSelf.registrationToken = registrationToken;
            NSLog(@"Registration Token: %@", registrationToken);
            [weakSelf subscribeToTopic];
            NSDictionary *userInfo = @{@"registrationToken":registrationToken};
            [[NSNotificationCenter defaultCenter] postNotificationName:weakSelf.registrationKey
                                                                object:nil
                                                              userInfo:userInfo];
        } else {
            NSLog(@"Registration to GCM failed with error: %@", error.localizedDescription);
            NSDictionary *userInfo = @{@"error":error.localizedDescription};
            [[NSNotificationCenter defaultCenter] postNotificationName:weakSelf.registrationKey
                                                                object:nil
                                                              userInfo:userInfo];
        }
    };
    return YES;
}

- (void)subscribeToTopic {
    // If the app has a registration token and is connected to GCM, proceed to subscribe to the
    // topic
    if (_registrationToken && _connectedToGCM) {
        [[GCMPubSub sharedInstance] subscribeWithToken:_registrationToken
                                                 topic:SubscriptionTopic
                                               options:nil
                                               handler:^(NSError *error) {
                                                   if (error) {
                                                       // Treat the "already subscribed" error more gently
                                                       if (error.code == 3001) {
                                                           NSLog(@"Already subscribed to %@",
                                                                 SubscriptionTopic);
                                                       } else {
                                                           NSLog(@"Subscription failed: %@",
                                                                 error.localizedDescription);
                                                       }
                                                   } else {
                                                       self.subscribedToTopic = true;
                                                       NSLog(@"Subscribed to %@", SubscriptionTopic);
                                                   }
                                               }];
    }
}

// [START connect_gcm_service]
- (void)applicationDidBecomeActive:(UIApplication *)application {
    // Connect to the GCM server to receive non-APNS notifications
    [[GCMService sharedInstance] connectWithHandler:^(NSError *error) {
        if (error) {
            NSLog(@"Could not connect to GCM: %@", error.localizedDescription);
        } else {
            _connectedToGCM = true;
            NSLog(@"Connected to GCM");
            // [START_EXCLUDE]
            [self subscribeToTopic];
            // [END_EXCLUDE]
        }
    }];
}
// [END connect_gcm_service]

// [START disconnect_gcm_service]
- (void)applicationDidEnterBackground:(UIApplication *)application {
    [[GCMService sharedInstance] disconnect];
    // [START_EXCLUDE]
    _connectedToGCM = NO;
    // [END_EXCLUDE]
}
// [END disconnect_gcm_service]

// [START receive_apns_token]
- (void)application:(UIApplication *)application
didRegisterForRemoteNotificationsWithDeviceToken:(NSData *)deviceToken {
    // [END receive_apns_token]
    // [START get_gcm_reg_token]
    // Create a config and set a delegate that implements the GGLInstaceIDDelegate protocol.
    GGLInstanceIDConfig *instanceIDConfig = [GGLInstanceIDConfig defaultConfig];
    instanceIDConfig.delegate = self;
    // Start the GGLInstanceID shared instance with the that config and request a registration
    // token to enable reception of notifications
    [[GGLInstanceID sharedInstance] startWithConfig:instanceIDConfig];
    _registrationOptions = @{kGGLInstanceIDRegisterAPNSOption:deviceToken,
                             kGGLInstanceIDAPNSServerTypeSandboxOption:@"NO"};
    [[GGLInstanceID sharedInstance] tokenWithAuthorizedEntity:_gcmSenderID
                                                        scope:kGGLInstanceIDScopeGCM
                                                      options:_registrationOptions
                                                      handler:_registrationHandler];
    // [END get_gcm_reg_token]
}

// [START receive_apns_token_error]
- (void)application:(UIApplication *)application
didFailToRegisterForRemoteNotificationsWithError:(NSError *)error {
    NSLog(@"Registration for remote notification failed with error: %@", error.localizedDescription);
    // [END receive_apns_token_error]
    NSDictionary *userInfo = @{@"error" :error.localizedDescription};
    [[NSNotificationCenter defaultCenter] postNotificationName:_registrationKey
                                                        object:nil
                                                      userInfo:userInfo];
}

// [START ack_message_reception]
- (void)application:(UIApplication *)application
didReceiveRemoteNotification:(NSDictionary *)userInfo {
    NSLog(@"Notification received: %@", userInfo);
    // This works only if the app started the GCM service
    [[GCMService sharedInstance] appDidReceiveMessage:userInfo];
    // Handle the received message
    // [START_EXCLUDE]
    [[NSNotificationCenter defaultCenter] postNotificationName:_messageKey
                                                        object:nil
                                                      userInfo:userInfo];
    // [END_EXCLUDE]
}

- (void)application:(UIApplication *)application
didReceiveRemoteNotification:(NSDictionary *)userInfo
fetchCompletionHandler:(void (^)(UIBackgroundFetchResult))handler {
    NSLog(@"Notification received: %@", userInfo);
    // This works only if the app started the GCM service
    [[GCMService sharedInstance] appDidReceiveMessage:userInfo];
    // Handle the received message
    // Invoke the completion handler passing the appropriate UIBackgroundFetchResult value
    // [START_EXCLUDE]
    [[NSNotificationCenter defaultCenter] postNotificationName:_messageKey
                                                        object:nil
                                                      userInfo:userInfo];
    handler(UIBackgroundFetchResultNoData);
    // [END_EXCLUDE]
}
// [END ack_message_reception]

// [START on_token_refresh]
- (void)onTokenRefresh {
    // A rotation of the registration tokens is happening, so the app needs to request a new token.
    NSLog(@"The GCM registration token needs to be changed.");
    [[GGLInstanceID sharedInstance] tokenWithAuthorizedEntity:_gcmSenderID
                                                        scope:kGGLInstanceIDScopeGCM
                                                      options:_registrationOptions
                                                      handler:_registrationHandler];
}
// [END on_token_refresh]

// [START upstream_callbacks]
- (void)willSendDataMessageWithID:(NSString *)messageID error:(NSError *)error {
    if (error) {
        // Failed to send the message.
    } else {
        // Will send message, you can save the messageID to track the message
    }
}

- (void)didSendDataMessageWithID:(NSString *)messageID {
    // Did successfully send message identified by messageID
}
// [END upstream_callbacks]

- (void)didDeleteMessagesOnServer {
    // Some messages sent to this device were deleted on the GCM server before reception, likely
    // because the TTL expired. The client should notify the app server of this, so that the app
    // server can resend those messages.
}

I am not a php script master so please help me that how i can resolve my issues.

Answer 1

I have added

 'content_available' => true,//to trigger when iOS app is in background
 'priority' => 'high',
 'notification' => $data,
 $data = array( 'message' => 'Hello World!', 'body' => 'Hello World!');

to your code. Please try below code;

<?php

// Payload data you want to send to iOSdevice(s)
// (it will be accessible via intent extras)    
$data = array( 'message' => 'Hello World!', 'body' => 'Hello World!');

// The recipient registration tokens for this notification
// http://developer.android.com/google/gcm/ 
$ids = array( 'kucy6xoUmx********eeRsla' );

// Send a GCM push
sendGoogleCloudMessage(  $data, $ids );

function sendGoogleCloudMessage( $data, $ids )
{
    // Insert real GCM API key from Google APIs Console
    // https://code.google.com/apis/console/        
    $apiKey = 'AIz******9JA';

    // Define URL to GCM endpoint
    $url = 'https://gcm-http.googleapis.com/gcm/send';

    // Set GCM post variables (device IDs and push payload)     
    $post = array(
                    'registration_ids'  => $ids,
                    'data'              => $data, 
                    'content_available'    => true,                 
                    'priority'              => 'high',    
                    'notification' => $data,               
                    );

    // Set CURL request headers (authentication and type)       
    $headers = array( 
                        'Authorization: key=' . $apiKey,
                        'Content-Type: application/json'
                    );

    // Initialize curl handle       
    $ch = curl_init();

    // Set URL to GCM endpoint      
    curl_setopt( $ch, CURLOPT_URL, $url );

    // Set request method to POST       
    curl_setopt( $ch, CURLOPT_POST, true );

    // Set our custom headers       
    curl_setopt( $ch, CURLOPT_HTTPHEADER, $headers );

    // Get the response back as string instead of printing it       
    curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true );

    // Set JSON post data
    curl_setopt( $ch, CURLOPT_POSTFIELDS, json_encode( $post ) );

    // Actually send the push   
    $result = curl_exec( $ch );

    // Error handling
    if ( curl_errno( $ch ) )
    {
        echo 'GCM error: ' . curl_error( $ch );
    }

    // Close curl handle
    curl_close( $ch );

    // Debug GCM response       
    echo $result;
}

?>

on IOS side; Follow orders on GCM Site

EDIT 1: You may try sending notification for ios;

I edited your php code above; Changes are;

'notification' => $data,

and

$data = array( 'message' => 'Hello World!', 'body' => 'Hello World!');

Answer 2

GCM receiving notification in invalid state 2.

Developers who are using GCM integration for both Android and iOS need to add specific things in their Post call to the GCM Server. For iOS: We need two additional things to make the same call work in iOS: 'notification' => $data, 'content_available'=> 'true',

The Apple push notifications service requires content_available is true. And then 'notification'=> $data helps the Notification center to know that the notification has arrived and needs to be pushed to the device.