feat: provide the eventService class for event management

Author: wewoor

src/services/eventService.ts

@@ -0,0 +1,49 @@
+import { EventEmitter } from 'mo/common/event';
+
+export const EventService = new EventEmitter();
+
+/**
+ * Emit decorator, when the function be called,
+ * it's going to notify the listener
+ * @param name Event name
+ */
+export function emit(name: string) {
+    return function(
+        target,
+        property: string,
+        descriptor: PropertyDescriptor,
+    ) {
+        const original = descriptor.value;
+        if (typeof original === 'function') {
+            descriptor.value = function(...args) {
+                try {
+                    const result = original.apply(this, args);
+                    EventService.emit(name, args);
+                    return result;
+                } catch (e) {
+                    throw e;
+                }
+            };
+        }
+        return descriptor;
+    };
+}
+
+
+/**
+ * When the event emitted, it's going to call target function
+ * @param name Event name
+ */
+export function subscribe(name: string | string []) {
+    return function(
+        target,
+        property: string,
+        descriptor: PropertyDescriptor,
+    ) {
+        const original = descriptor.value;
+        if (typeof original === 'function') {
+            EventService.subscribe(name, original);
+        }
+        return descriptor;
+    };
+}