render file preview iframe in subdomain

preview/talk.html

@@ -0,0 +1,72 @@
+Hello
+
+<script>
+	if (
+		'serviceWorker' in navigator
+	) {
+		// Delay registration until after the page has loaded, to ensure that our
+		// precaching requests don't degrade the first visit experience.
+		// See https://developers.google.com/web/fundamentals/instant-and-offline/service-worker/registration
+		window.addEventListener('load', function () {
+			// Your service-worker.js *must* be located at the top-level directory relative to your site.
+			// It won't be able to control pages unless it's located at the same level or higher than them.
+			// *Don't* register service worker file in, e.g., a scripts/ sub-directory!
+			// See https://github.com/slightlyoff/ServiceWorker/issues/468
+			navigator.serviceWorker
+				.register('service-worker.js')
+				.then(function (reg) {
+					// updatefound is fired if service-worker.js changes.
+					reg.onupdatefound = function () {
+						// The updatefound event implies that reg.installing is set; see
+						// https://w3c.github.io/ServiceWorker/#service-worker-registration-updatefound-event
+						var installingWorker = reg.installing;
+
+						installingWorker.onstatechange = function () {
+							/* eslint-disable default-case */
+							switch (installingWorker.state) {
+								case 'installed':
+									if (navigator.serviceWorker.controller) {
+										// At this point, the old content will have been purged and the fresh content will
+										// have been added to the cache.
+										// It's the perfect time to display a "New content is available; please refresh."
+										// message in the page's interface.
+										console.log('New or updated content is available.');
+
+									} else {
+										// At this point, everything has been precached.
+										// It's the perfect time to display a "Content is cached for offline use." message.
+										console.log('Content is now available offline!');
+										if (window.alertsService) {
+											window.alertsService.add(
+												'Web Maker is now ready to be used offline.'
+											);
+										}
+									}
+									break;
+
+								case 'redundant':
+									console.error(
+										'The installing service worker became redundant.'
+									);
+									break;
+							}
+						};
+					};
+				})
+				.catch(function (e) {
+					console.error('Error during service worker registration:', e);
+				});
+		});
+	}
+
+</script>
+
+
+<script>
+	console.log('controller', navigator.serviceWorker.controller)
+	window.addEventListener('message', (e) => {
+		console.log(88, e.data);
+		navigator.serviceWorker.controller.postMessage(e.data);
+	});
+
+</script>