Send useful notifications to a user based on location

[marcveens]

Still needs some research to do:

• What are the push/notification possibilities in a PWA? What can be done, what cannot?
• Can we send a push based on location?
• Who is in charge of sending a push? Who can send it?
• How can we send a user to a certain PWA page after clicking the notification?

[marcveens]

When to send a notification
For now, let's say:

• If a user moved 100km within 4 hours

What we have to do after fetching a new location:

• Find out how many records were saved within 4 hours (or 240 minutes or 14400 seconds)
• Sum the distance of all these records
• If a user moved more than 100km (or 100000 meters) send a push notification containing a message like "Take some rest, here are some hotels nearby"

[marcveens]

Currently we make use of the web-push library: https://github.com/web-push-libs/web-push.

We created an Azure site to which we deployed the NodeJS server part of our push service. This service contains a /service endpoint which will be used to store the client subscriptions in memory (Later on we have to save the subscription keys in a DB or FS). We also have a /notify/all endpoint which is used to push messages to all subscribed clients.

Clientside we added some event listeners to the service-worker.js file which handle the push message and create a notification out of it.

[marcveens]

Notifications work, but it seems that a custom badge doesn't work. The only thing that shows is the default bell icon:

[marcveens]

In order to open an external website after clicking on a notification, use:

event.waitUntil(clients.openWindow('https://www.nu.nl'));

In order to open the app again, use:

event.waitUntil(clients.openWindow('/'));