Implement service worker for offline notifications #480
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Now, the service worker only displays a message, when no gotify window is open (implemented in 5aca059). I wasn't able to find a way to play custom sounds with service worker notifications, sadly. |
| stores.currentUser.tryAuthenticate().then(() => { | ||
| // always request notification permission when logged in | ||
| Notification.requestPermission() | ||
| .then(perm => console.log("Notification permissions " + perm)) | ||
| .catch(console.error) | ||
| // reregister worker | ||
| registerNotificationWorker(stores.currentUser.token()); | ||
| }).catch(() => {}); |
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Please add another button under the enable notifications button, something like "enable background notifications". Should probably only visible if the notification permission was given. Gotify must not request this permission without user interaction, see #264
The button should be a toggle, enabling and disabling the notifications.
| const ws = new WebSocket(`${wsProto}//${host}/stream?token=${gotifyKey}`) | ||
| console.log("Notification worker connected to websocket, waiting for messages") | ||
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| ws.onmessage = (event) => { |
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We probably need some reconnect logic here, otherwise the connection can break in the background and then the user doesn't get notifications anymore.
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I'm afraid I have some bad news. After testing this for a while now, I have come to the conclusion several times that the service worker is unfortunately not persistent. It stays online for a few minutes up to about half an hour after the last Gotify tab is closed. I have read in some resources that you can keep Service worker "alive" by having it send itself regular messages via The So I think this will not work here as intended. I'm closing the pull request now, but maybe it will be useful in the future if there is a way to actually use the Push API with a self-hosted server, or the "push" event can be triggered otherwise. My sources are attached, in case someone wants to do some more research or to follow the whole thing. |
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@MexHigh thanks for your research! |
This is a draft
Fixes #344
How does it work
After logging in, a new service worker is created. The
gotify-login-keygets passed to it via query parameter so that it can subscribe to the Websocket/streamendpoint. On incoming messages, it creates a notification. This way, no third party server must be used (e.g. a vendor server for the Webpush API).The worker keeps running until the user logs out and the client is removed. It keeps running when the browser is closed.
It also seems like notifications work on android from within the browser now, as android only supports notifications via Service Worker (source).
(When testing, do not forget applying this workaround when not testing over HTTPS or
localhost.)Todos
Please add your changes if necessary. I've kept the
console.logstatements for easier testing. They need to be removed before merging, of course.