Background push notifications in Xamarin

Question

Please consider the following issue:

I am using the following plugin for Xamarin to perform push notifications, I am attempting to get this running on both iOS and Androids.

https://github.com/CrossGeeks/FirebasePushNotificationPlugin

I am also using the following PHP code to send push notifications to the device from a website.

$fields = array
(
    'to' => $ID->notification_token,
    "content_available" => true,
    'priority'=>10,
    'notification' => array('title' => 'You have a new message', 'body' => 'Hooray', 'sound'=>'default', 'vibration'=>'default'),
);

$headers = array
(
    'Authorization: key=' . PUSH_NOTIFICATION_API_ACCESS_KEY,
    'Content-Type: application/json',
);

$ch = curl_init();
curl_setopt( $ch,CURLOPT_URL, 'https://android.googleapis.com/gcm/send' );
curl_setopt( $ch,CURLOPT_POST, true );
curl_setopt( $ch,CURLOPT_HTTPHEADER, $headers );
curl_setopt( $ch,CURLOPT_RETURNTRANSFER, true );
curl_setopt( $ch,CURLOPT_SSL_VERIFYPEER, false );
curl_setopt( $ch,CURLOPT_POSTFIELDS, json_encode( $fields ) );
$result = curl_exec($ch );
curl_close( $ch );
echo $result;

Now the issue is on iOS I find that the push notification is reliable and runs perfectly when the app is in the foreground, but as soon as I background it (or lock the screen), they stop coming through until I foreground it again, then all of the notifications sent while it was in the background all come through at once.

I have enabled background processes in my info.plist as according to the plugins "Getting Started" guide.

I have tried changing content_availiable to content-availiable, also moving it into the notification array, also setting the value of it to true, 'true', 1 and '1'

I have also tried adding "alert" => "" to both the notification and the overall payload, however I still can't get it to work, outside of the foreground unlocked state.

I also notice that nothing appears to be triggering in the actual notification list (Pulled down from top of screen), the only way I know that the notifications are being received is from playing a certain sound file as it comes through and writing in the debug log.

Any assistance will be appreciated, thanks for your time.

Answer 1

Make sure your message Json has the {"content-available" : "1", "alert" : ""} attributes if you want it to show up on iOS when not running in background.

As for Android, push notifications really are not 100% realiable, there are device specific impediments that may block your notification from showing up.

There might be a "test send" feature on Firebase (I've only used Azure Push Hub so far) so you can try and see if your message Json is configured correctly.

Answer 2

I would try sending a Data Message instead

$fields = array
(
    'to' => $ID->notification_token,
    "content_available" => true,
    'priority'=>10,
    'data' => array('title' => 'You have a new message', 'body' => 'Hooray', 'sound'=>'default', 'vibration'=>'default'),
);