js/html/ServiceWorker.html">ServiceWorker</a></code></h3><div class="doc"><p>Returns a service worker whose state is either <code>activating</code> or <code>activated</code>. This is initially set to <code>null</code>. An active worker will control a <code>ServiceWorkerClient</code> if the client's URL falls within the scope of the registration (the <code>scope</code> option set when <code><a href="../../js/html/ServiceWorkerContainer.html#register">ServiceWorkerContainer.register</a></code> is first called