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SYS_MessageBus.subscribe() method

Private message bus: subscribe to a message

Signature

function subscribe(topic: string, callbackFn: (message: any) => void): ISYS_MessageBusTask;

Parameters

Parameter	Type	Description
topic	string	Theme
callbackFn	(message: any) => void	Callback after receiving the message

Returns

ISYS_MessageBusTask

Message bus task

Remarks

Persistent subscription message

Example

// 1. 持久订阅主题
const received = [];
const task = eda.sys_MessageBus.subscribe('嘉立创示例_订阅', (message) => {
	received.push(message);
});

// 2. 连续发布多条消息，每条都能收到
eda.sys_MessageBus.publish('嘉立创示例_订阅', '第一条');
eda.sys_MessageBus.publish('嘉立创示例_订阅', '第二条');
console.log('已收到：', received.join('、'));

// 3. cancel 之后不再接收
task.cancel();
eda.sys_MessageBus.publish('嘉立创示例_订阅', '取消后的消息');
console.log('cancel 后仍停留在：', received.join('、'));