You can listen to the unload or beforeunload events like this:
export class AppComponent {
@HostListener('window:unload', [ '$event' ])
unloadHandler(event) {
// ...
}
@HostListener('window:beforeunload', [ '$event' ])
beforeUnloadHandler(event) {
// ...
}
}
See also
Detect browser or tab closing
https://developer.mozilla.org/de/docs/Web/Events/unload