pop-up notifications from a widget

What's the proper way of showing a pop-up notification from a widget?

So far I updated widbt_notify to use the following code:

// NRF.on('disconnect',
var tId = setTimeout(load, 3000);
E.showAlert(/*LANG*/'Connection\nlost.', 'BLUETOOH').then(()=>{
  // ok clicked before timeout
  clearTimeout(tId);
  load();
});

The problem I get is that if the watchface calls its draw() function while popup is still visible, the popup screen is (partially) overwritten.

I checked other widgets:

$ grep showAlert wid*/widget.js

But it seems there's no other examples.

One solution would be to complement a widget with a tiny app, which is launched only to show a popup. Sounds like an overkill. Is there a better way? If not, is there a way to ship a widget with an app, while hiding the app from the launcher?

Is there a better way?

Not really, and you probably need to load() the clock anyway after you're done, because it needs to fully redraw itself.
The launcher only shows <appid>.app.js files, so you can just add e.g. <appid>.showAlert.js and load(<appid>.showAlert.js).

There is an actual 'notification' app/library that handles this: https://github.com/espruino/BangleApps/tree/master/apps/notify

On Bangle.js 1 it can use the in-LCD buffer to scroll the screen and display the notification, but on Bangle.js 2 the only option is basically what you're doing - display and then reload after (done by notifyfs).

Using require("notify") is best though , as hopefully it some point the situation will improve, and when it does we can just update the library.