Initial commit

static/subscription.mjs

@@ -0,0 +1,41 @@
+
+export class Subscription_Endpoint extends EventTarget {
+
+	async connect(path) {
+		const wsProtocol = location.protocol === 'https:' ? 'wss:' : 'ws:';
+		const wsUrl = `${wsProtocol}//${location.host}${path}`;
+
+		const ws = new WebSocket(wsUrl);
+
+		await new Promise((resolve, reject) => {
+			ws.addEventListener('open', resolve, { once: true });
+			ws.addEventListener('error', reject, { once: true });
+		});
+
+		ws.addEventListener('message', ev => {
+			this.dispatchEvent(new CustomEvent('message', { detail: ev.data }));
+		});
+
+		ws.addEventListener('close', () => {
+			this.dispatchEvent(new Event('close'));
+		});
+
+		ws.addEventListener('error', err => {
+			this.dispatchEvent(new CustomEvent('error', { detail: err }));
+		});
+
+		this.ws = ws;
+		return ws;
+	}
+
+	subscribe(resource) {
+		const { ws } = this;
+		ws.send(JSON.stringify({
+			cmd: 'subscribe',
+			resource
+		}));
+	}
+
+
+
+}