Recording/Catching push notifications with chrome extension - google-chrome

Question

I'm trying to catch push notifications that get sent to my chrome browser with a chrome extension to then write it to a file or run code on receiving it.
I'm sure the issue I'm having is simple enough for some of you so I will share what I've found so far and my code.
notifhook.js
(function() {
// save the original function
var origCreateNotif = notifications.createNotification;
// overwrite createNotification with a new function
notifications.createNotification = function(img, title, body) {
// call the original notification function
var result = origCreateNotif.apply(this, arguments);
alert("Function was called");
// bind a listener for when the notification is displayed
result.addEventListener("display", function() {
alert("Triggered code");
// do something when the notification is displayed
});
return result;
}
})()
manifest.json
{
"name": "Push",
"description": "Relay push notifications",
"version": "3.0",
"permissions": ["notifications"],
"web_accessible_resources": ["notifhook.js"],
"content_scripts" : [{
"run_at" : "document_start",
"matches" : ["<all_urls>"],
"js" : ["inject.js"]
}],
"manifest_version": 2
}
inject.js
var s = document.createElement("script");
s.src = chrome.extension.getURL("notifhook.js");
document.documentElement.appendChild(s);
Most of the code used was taken here :
How can I listen to notifications?
I am using this webapp to test my extension :
http://ttsvetko.github.io/HTML5-Desktop-Notifications/
So, to my knowledge what is happening so far is that the block containing my main function is being added to the webpage just fine
since I can alert at the start of it and on every page load it will be triggered.
What is failing is when I receive a push notification the event listener isn't working or my function names are wrong. I read somewhere that webkitNotifications was replaced with just 'notifications'.
Any help is much appreciated.

Answer 1

If the code is in service worker, like when there are notifications when you close the browser tab/window for the app (like on facebook) then you need to overwirte registration of service worker.
// taken from https://googlechrome.github.io/samples/service-worker/post-message/index.html
function sendMessage(message) {
return new Promise(function(resolve, reject) {
var messageChannel = new MessageChannel();
messageChannel.port1.onmessage = function(event) {
if (event.data.error) {
reject(event.data.error);
} else {
resolve(event.data);
}
};
navigator.serviceWorker.controller.postMessage(message,
[messageChannel.port2]);
});
}
(function() {
if ('serviceWorker' in navigator) {
var register = navigator.serviceWorker.register;
navigator.serviceWorker.register = function() {
register.call(navigator.serviceWorker, "yourscript.js").then(function() {
sendMessage({args: [].slice.call(arguments)});
});
};
}
})();
and in service worker (yourscript.js) you need to call importScript with original script taken from post message
// put content of notifhook.js file here
self.addEventListener('message', function handler(event) {
if (event.data && event.data.args && event.data.args.length) {
importScripts(event.data.args[0]); // import original script
self.removeEventListener('message', handler);
}
});