How to send notification to specific user from web application to mobile application

Question

I have a web application and mobile application to manage user parcels. Now, i want when a user receives a parcel, send a notification from web application to him on mobile application.

I used OneSignal and connected my mobile app successfully, but don't know which and how call an api to send notification to specific user?

Also, I read the documentation, but couldn't find any way and example for this requirement

Answer 1

The most popular way to send push notification to mobile devices is by using Google Firebase push notification .

Every device is tracked by unique device token generated by Firebase ( Android or iOS ).

Solution for your Usecase:

• Whenever user tries to login into your application just trigger an API call to backend.

• That API will put an entry to the database with userId and device token.

• When you going to send push notification just get the device token from the database based on userId using Firebase SDK.

Example:

To send notification for multiple device ids that may be Android or IOS.

You can use MulticastMessage in fireBase.

                    MulticastMessage multiCast = MulticastMessage.builder()
                        .putAllData(new HashMap<String, String>() { put("message":"hi"); })
                        .setApnsConfig(ApnsConfig.builder().build())
                        .setAndroidConfig(AndroidConfig.builder().build())
                        .addAllTokens(Arrays.asList("devicetoken1", "devicetoken2"))
                        .build();

For reference : https://firebase.google.com/docs/cloud-messaging/send-message