How can I initiate a PWA (progressive webapp) open from a click on a push notification?

Question

Following this example, I see how PWA can open urls but how can I use push notification to launch the app itself? Not in the browser but the full screen version PWA.

Answer 1

As of Oct/2018:

I managed it to work using Chrome 69.

In this example, it's a sub-application (www.example.com/application).

In short: double check the paths!

And also I had issues with not loaded cookies (login info) whenever I launched the app from a Push Notification, it opened fine, but not logged in. If you close it and tap the app icon previously added on homescreen, the app is launched already logged in.

I accomplished it using the following (see comments):

1) serviceworker.js

self.addEventListener('notificationclick', function (event)
{
    //For root applications: just change "'./'" to "'/'"
    //Very important having the last forward slash on "new URL('./', location)..."
    const rootUrl = new URL('./', location).href; 
    event.notification.close();
    event.waitUntil(
        clients.matchAll().then(matchedClients =>
        {
            for (let client of matchedClients)
            {
                if (client.url.indexOf(rootUrl) >= 0)
                {
                    return client.focus();
                }
            }

            return clients.openWindow(rootUrl).then(function (client) { client.focus(); });
        })
    );
});

2) manifest.json

{
    "short_name": "AppNickName",
    "name": "ApplicationName",
    "icons": [
        {
            "src": "./icon.png",
            "sizes": "36x36",
            "type": "image/png",
            "density": 0.75
        }
    ],
    "start_url": "./",  //This matters
    "display": "standalone",  //This also matters
    "gcm_sender_id": "103953800507", //FCM always uses this number (April 2019)
    "background_color": "#c8c8c8",
    "theme_color": "#c8c8c8",
    "orientation": "any"
}