How to subscribe to topics with web browser using Firebase Cloud Messaging

Question

I\'m trying to find a way to send a notification using Firebase Cloud Messaging to all of my app\'s users, but I have a web-only app. I\'ve seen solutions that appear to be

Answer 1

Franks solution is still valid. However you need to have a server that does the subscribe for you.

function subscribeTokenToTopic(token, topic) {
  fetch('https://myserver.com/'+token+'/rel/topics/'+topic, {
    method: 'POST',
    headers: new Headers({
      'Authorization': 'Bearer '+ oauthToken
    })
  }).then(response => {
    if (response.status < 200 || response.status >= 400) {
      throw 'Error subscribing to topic: '+response.status + ' - ' + response.text();
    }
    console.log('Subscribed to "'+topic+'"');
  }).catch(error => {
    console.error(error);
  })
}

then your server has a rest call something like this:

(java spring)

@RequestMapping(value = "/{token}/rel/topics/{topic}", method = RequestMethod.POST)
public ResponseEntity subscribeTokenToTopic(@PathVariable("token") String token, @PathVariable("topic") String topic)  throws ServletException {
  URL url = new URL("https://iid.googleapis.com/iid/v1/"+token+"/rel/topics/"+topic);
  // make https post call here.. 
  ...
}

Hopefully that makes sense.