Initial use of simple message bus

static/js/mbus.mjs

@@ -0,0 +1,17 @@
+export class MessageBus {
+	constructor() {
+		this.bus = new EventTarget()
+	}
+
+	subscribe(eventName, fn) {
+		this.bus.addEventListener(eventName, fn)
+	}
+
+	unsubscribe(eventName, fn) {
+		this.bus.removeEventListener(eventName, fn)
+	}
+
+	dispatch(eventName, data) {
+		this.bus.dispatchEvent(new CustomEvent(eventName, { detail: data }))
+	}
+}