alibaba · JackLian · Aug 16, 2023 · Aug 16, 2023
@@ -25,6 +25,19 @@ on(event: string, listener: (...args: any[]) => void): IPublicTypeDisposable;
 ```
 相关类型：[IPublicTypeDisposable](https://github.com/alibaba/lowcode-engine/blob/main/packages/types/src/shell/type/disposable.ts)
 
+### prependListener
+监听事件，会在其他回调函数之前执行
+
+```typescript
+/**
+ * 监听事件，会在其他回调函数之前执行
+ * @param event 事件名称
+ * @param listener 事件回调
+ */
+prependListener(event: string, listener: (...args: any[]) => void): IPublicTypeDisposable;
+```
+相关类型：[IPublicTypeDisposable](https://github.com/alibaba/lowcode-engine/blob/main/packages/types/src/shell/type/disposable.ts)
+
 ### off
 取消监听事件
 

@@ -55,6 +55,14 @@ export class EventBus implements IEventBus {
     };
   }
 
+  prependListener(event: string, listener: (...args: any[]) => void): () => void {
+    this.eventEmitter.prependListener(event, listener);
+    this.getLogger().debug(`${this.getMsgPrefix('prependListener')} ${event}`);
+    return () => {
+      this.off(event, listener);
+    };
+  }
+
   /**
    * 取消监听事件
    * @param event 事件名称

@@ -36,6 +36,20 @@ export class Event implements IPublicApiEvent {
     }
   }
 
+  /**
+   * 监听事件，会在其他回调函数之前执行
+   * @param event 事件名称
+   * @param listener 事件回调
+   */
+  prependListener(event: string, listener: (...args: any[]) => void): IPublicTypeDisposable {
+    if (isPluginEventName(event)) {
+      return this[eventBusSymbol].prependListener(event, listener);
+    } else {
+      logger.warn(`fail to prependListener event ${event}, event should have a prefix like 'somePrefix:eventName'`);
+      return () => {};
+    }
+  }
+
   /**
    * 取消监听事件
    * @param event 事件名称

@@ -10,6 +10,13 @@ export interface IPublicApiEvent {
    */
   on(event: string, listener: (...args: any[]) => void): IPublicTypeDisposable;
 
+  /**
+   * 监听事件，会在其他回调函数之前执行
+   * add monitor to a event
+   * @param event 事件名称
+   * @param listener 事件回调
+   */
+  prependListener(event: string, listener: (...args: any[]) => void): IPublicTypeDisposable;
 
   /**
    * 取消监听事件