dp-mq-client

。 简单易用的mqtt 客户端 库。

一、安装

• npm i dp-ioc

二、快速开始

import { MqttClient, connect } from "mqtt";
import { DpMqClient, MqMessage } from "dp-mq-client"


//定义一个消息体
@MqMessage({
    topic: "a/b/c", // 消息主题
})
class TestMsg {
    constructor(
        public name: string,
        public age: number
    ) { }
}


// 初始化客户端
let mqttClient = connect("mqtt://127.0.0.1", { port: 10084, password: "xx", username: "xxx" });
mqttClient.on("connect", () => {
    let dpMq = new DpMqClient();
    dpMq.init(mqttClient);


    // 实例化消息体
    let testMsg = new TestMsg("rajan", 18);

    // 订阅消息
    dpMq.subscribe<TestMsg>(testMsg, (msg) => {
        // 当有消息时触发回调。
    })

    // 发布消息
    dpMq.publish(testMsg);

    // 取消订阅消息 
    dpMq.unsubscribe(testMsg);

})

注意，取消订阅时，需要传入消息体实例而非类

如果使用在dp-uni-api-framework 框架下，可以如此引入:

...
class App {

    @Inject(DpMqClient)
    dpMqClient:DpMqClient;

    @BeforeBoot
    async beforeBoot(){

        //  callback写法
        let mqttClient = connect("mqtt://127.0.0.1", { port: 10084, password: "xx", username: "xxx" });
        mqttClient.on("connect", () => {
            this.dpMqClient.init(mqttClient);
        })

        // 或者使用await写法 [推荐]
        await new Promise((resolve,reject)=>{
            let mqttClient = connect("mqtt://127.0.0.1", { port: 10084, password: "xx", username: "xxx" });
            mqttClient.on("connect", () => {
                this.dpMqClient.init(mqttClient);
                resolve();
            })
            mqttClient.on("error", () => {
                reject();
            })
        })
    }
}
...

三、高级用法

3.1 订阅消息时， 同一个消息体类多个实例对象，每个实例对象的消息回调是独立的。

@MqMessage({
    topic: "a/b/c", 
})
class TestMsg {
    constructor(
        public name: string,
        public age: number
    ) { }
}

//定义两个消息实例
let testMsg1 = new TestMsg("rajan1", 19);
let testMsg2 = new TestMsg("rajan2", 20);


// 订阅消息
dpMq.subscribe<TestMsg>(testMsg1, (msg) => {
     // 消息回调1 
})

// 订阅消息
dpMq.subscribe<TestMsg>(testMsg2, (msg) => {
     // 消息回调2
})

当然，取消订阅（unsubscribe）也是独立的。

3.2 动态更新 meta 元信息

import { metaUpdate,MqMessage } from "dp-mq-client"

@MqMessage({
    topic: "a/b/c", 
})
class TestMsg {
    constructor(
        public name: string,
        public age: number
    ) { }
}

let testMsg1 = new TestMsg("rajan1", 19);
metaUpdate(testMsg1,{ topic: "a/c/c"});// 更新testMsg1对象的元信息

四、支持

如果在使用过程中，遇到问题，请到git仓库反馈 仓库地址