uniapp mqtt

Uniapp is a cross-platform framework that allows developers to build mobile applications for multiple platforms, including iOS, Android, and HTML5. MQTT is a lightweight messaging protocol that is commonly used for IoT (Internet of Things) applications.

To use MQTT in a Uniapp application, developers can use the Paho MQTT client library, which is available for JavaScript. The library can be imported into the Uniapp project and used to create MQTT connections and subscribe to topics.

Here is an example of how to use the Paho MQTT library in a Uniapp application:

1. Install the library using npm:

npm install paho-mqtt --save

2. Import the library in your Uniapp project:

import { Client } from 'paho-mqtt';

3. Create an MQTT client:

const client = new Client({
  host: 'mqtt.example.com',
  port: 8883,
  useSSL: true,
  username: 'username',
  password: 'password',
});

4. Connect to the MQTT broker:

client.connect({
  onSuccess: () => {
    console.log('Connected to MQTT broker.');
  },
  onFailure: (errorCode) => {
    console.error('Failed to connect to MQTT broker. Error code:', errorCode);
  },
});

5. Subscribe to a topic:

client.subscribe('my/topic', {
  onSuccess: () => {
    console.log('Subscribed to topic.');
  },
  onFailure: (errorCode) => {
    console.error('Failed to subscribe to topic. Error code:', errorCode);
  },
});

6. Receive messages:

client.onMessageArrived = (message) => {
  console.log('Received message:', message.payloadString);
};

With these steps, developers can use MQTT in their Uniapp applications to communicate with IoT devices and other MQTT clients.