Fetch user location as background process

[marcveens]

Figure out if it's possible to fetch the user's location as a background process.

Goal: We would like to send a user messages based on their location and time.

[marcveens]

Seems that it's not possible to fetch location using a service worker, see w3c/ServiceWorker#745.

There is a specs draft by W3C, but it's written in 2016 and no longer maintained: https://w3c.github.io/geofencing-api/.

There is a still active proposal for Geofencing in a PWA, but still no outcome: https://discourse.wicg.io/t/proposal-expose-geolocation-to-service-workers/2588/30.

There are a few alternatives:

• Jake Archibald (one of the designers of the ServiceWorker) suggests to look at https://w3c.github.io/wake-lock/. This should keep the page alive, not by using a ServiceWorker. Support seems to be poor. Needs more research
• Keep track of user location and time on the website everytime they open it. For example: User opens website at 8:00 at location A and opens it again at 12:00 at location B. We already know the time in between the 2 actions, for distance we have two options:
  • Calculate the approximate distance as the crow flies (hemelsbreed) (Not very accurate)
  • Calculate a more precise distance using a geoservice (by Google Maps API or another service) (Accurate, slower to fetch, might have to be paid for)
    Based on this data we know how long someone has been on the road.
• Create a hybrid web app in order to use Geofencing, which is supported natively: (https://ionicframework.com/docs/native/geofence/) (This is probably the worst solution of all, since we want a PWA)