Nodebb: Installable PWA

[oplik0]

While NodeBB is a pretty progressive web application, it doesn't fulfill all of the requirements that will make it an installable app via browsers.
Checklist of required changes (based on a lighthouse check on community.nodebb.org and try.nodebb.org):

• [x] Register a service worker that responds with a http 200 when offline
• [x] short_name attribute in manifest.json
• [x] PNG icon with a size of at least 512px in manifest.json
• [x] background_color and theme_color attributes in manifest.json (ideally configurable in ACP)

Currently all of these are possible via plugin interfaces (you can set up a route to a service worker, create a client script that registers it and add all required parameters to manifest.json via the manifest.build hook), but I think this should also be added to core NodeBB to make the experience more streamlined.
(Also - in this topic there was a recommendation for opening an issue here, but I can't find it)

While it would also be possible to add web push support along with this feature, I think instead NodeBB should just have a basic service worker and a way for plugins to replace/modify it easily. Web APIs change, and there can be reasons for using alternatives, so not locking it to one push API and library seems like the best option.

[julianlam]

FWIW PWA compliance is one of the projects on our to-do list, and is something we'd want in core, and not a plugin. :smile:

[psychobunny]

Demo here: https://community.nodebb.org/

Probably won't work on anything but the latest desktop/mobile chrome/FF; it certainly does not work on iOS

Next steps are offline access + desktop/mobile notifs, track these separately IMO