ServiceWorker.state

The state read-only property of the ServiceWorker interface returns a string representing the current state of the service worker. It can be one of the following values: installing, installed, activating, activated, or redundant.

Syntax

someURL = ServiceWorker.state 

Value

A ServiceWorkerState definition (see the spec.)

Examples

This code snippet is from the service worker registration-events sample (live demo). The code listens for any change in the ServiceWorker.state and returns its value.

var serviceWorker;
if (registration.installing) {
  serviceWorker = registration.installing;
  document.querySelector('#kind').textContent = 'installing';
} else if (registration.waiting) {
  serviceWorker = registration.waiting;
  document.querySelector('#kind').textContent = 'waiting';
} else if (registration.active) {
  serviceWorker = registration.active;
  document.querySelector('#kind').textContent = 'active';
}

if (serviceWorker) {
  logState(serviceWorker.state);
  serviceWorker.addEventListener('statechange', function(e) {
  logState(e.target.state);
  });
}

Specifications

Browser compatibility

[1] Service workers (and Push) have been disabled in the Firefox 45 and 52 Extended Support Releases (ESR.)

[2] Service workers is available in Microsoft Edge starting EdgeHTML 16 behind a flag.