Push Notification, token expire?

Question

I'm working on a mobile application and i'm on Push Notification.

I can retrieve a token from a phone (apple or android) for send a push but i have a question :

This token is always the same ? If a get one time the token, i need to check if the token change ?

Answer 1

From apple documentation,

The form of this phase of token trust ensures that only APNs generates the token which it will later honor, and it can assure itself that a token handed to it by a device is the same token that it previously provisioned for that particular device—and only for that device.

If the user restores backup data to a new device or reinstalls the operating system, the device token changes.

So, its always good to update the server with the token received from APN. As part of optimisation, if you are receiving the same token, there is no need to update the server.

Answer 2

For Android:

It depends on your implementation, but what is recommended from google is that the registration id, can be changed after the app is updated...

Everytime the registration id is changed, the client should update the server with the new value.

check: http://developer.android.com/google/gcm/client.html#sample-register

if (checkPlayServices()) {
        gcm = GoogleCloudMessaging.getInstance(this);
        regid = getRegistrationId(context);

        if (regid.isEmpty()) {
            registerInBackground();
        }
    } else {
        Log.i(TAG, "No valid Google Play Services APK found.");
    }

 private void registerInBackground() {
new AsyncTask() {
    @Override
    protected String doInBackground(Void... params) {
        String msg = "";
        try {
            if (gcm == null) {
                gcm = GoogleCloudMessaging.getInstance(context);
            }
            regid = gcm.register(SENDER_ID);
            msg = "Device registered, registration ID=" + regid;

            // You should send the registration ID to your server over HTTP,
            // so it can use GCM/HTTP or CCS to send messages to your app.
            // The request to your server should be authenticated if your app
            // is using accounts.
            sendRegistrationIdToBackend();

            // For this demo: we don't need to send it because the device
            // will send upstream messages to a server that echo back the
            // message using the 'from' address in the message.

            // Persist the regID - no need to register again.
            storeRegistrationId(context, regid);
        } catch (IOException ex) {
            msg = "Error :" + ex.getMessage();
            // If there is an error, don't just keep trying to register.
            // Require the user to click a button again, or perform
            // exponential back-off.
        }
        return msg;
    }

    @Override
    protected void onPostExecute(String msg) {
        mDisplay.append(msg + "\n");
    }
}.execute(null, null, null);
...
}