How to use azure-iot-mqtt-base - 7 common examples

_onEnter: (disconnectedCallback, err, result) => {
            if (disconnectedCallback) {
              if (err) {
                /*Codes_SRS_NODE_DEVICE_MQTT_16_019: [The `connect` method shall calls its callback with an `Error` that has been translated from the `MqttBase` error using the `translateError` method if it fails to establish a connection.]*/
                disconnectedCallback(translateError(err));
              } else {
                disconnectedCallback(undefined, result);
              }
            } else {
              /* Codes_SRS_NODE_DEVICE_MQTT_18_026: When MqttTransport fires the close event, the Mqtt object shall emit a disconnect event */
              this.emit('disconnect', err);
            }
          },
          /*Codes_SRS_NODE_DEVICE_MQTT_16_021: [The `disconnect` method shall call its callback immediately with a `null` argument and a `results.Disconnected` second argument if `MqttBase` is already disconnected.]*/

this._config = config;
    this._topicTelemetryPublish = 'devices/' + this._config.deviceId + '/messages/events/';
    this._topicMessageSubscribe = 'devices/' + this._config.deviceId + '/messages/devicebound/#';
    this._topicMethodSucbscribe = '$iothub/methods/POST/#';

    debug('topic publish: ' + this._topicTelemetryPublish);
    debug('topic subscribe: ' + this._topicMessageSubscribe);
    const sdkVersionString = encodeURIComponent('azure-iot-device/' + packageJson.version);

    /*Codes_SRS_NODE_DEVICE_MQTT_16_016: [The Mqtt constructor shall initialize the `uri` property of the `config` object to `mqtts://`.]*/
    (this._config as any).uri = 'mqtts://' + config.host;
    /* Codes_SRS_NODE_DEVICE_MQTT_18_025: [ If the Mqtt constructor receives a second parameter, it shall be used as a provider in place of mqtt.js ]*/
    if (provider) {
      this._mqtt = provider;
    } else {
      this._mqtt = new MqttBase(sdkVersionString);
    }

    /* Codes_SRS_NODE_DEVICE_MQTT_18_026: When MqttTransport fires the close event, the Mqtt object shall emit a disconnect event */
    this._mqtt.on('error', (err) => {
      debug('on close');
      this._fsm.handle('disconnect', () => {
        this.emit('disconnect', err);
      });
    });

    this._mqtt.on('message', this._dispatchMqttMessage.bind(this));

    // MQTT topics to subscribe to
    this._topics = {
      'message': {
        name: this._topicMessageSubscribe,

this._mqtt.publish(topic, body.toString(), { qos: 0, retain: false }, (err, puback) => {
              if (err) {
                /* Codes_SRS_NODE_DEVICE_MQTT_18_016: [** If an error occurs in the `sendTwinRequest` method, the `done` callback shall be called with the error as the first parameter. **]** */
                /* Codes_SRS_NODE_DEVICE_MQTT_18_024: [** If an error occurs, the `sendTwinRequest` shall use the MQTT `translateError` module to convert the mqtt-specific error to a transport agnostic error before passing it into the `done` callback. **]** */
                callback(translateError(err));
              } else {
                /* Codes_SRS_NODE_DEVICE_MQTT_18_004: [** If a `done` callback is passed as an argument, The `sendTwinRequest` method shall call `done` after the body has been published. **]** */
                /* Codes_SRS_NODE_DEVICE_MQTT_18_017: [** If the `sendTwinRequest` method is successful, the first parameter to the `done` callback shall be null and the second parameter shall be a MessageEnqueued object. **]** */
                callback(null, new results.MessageEnqueued(puback));
              }
            });
          },

constructor(mqttBase?: MqttBase) {
    super();
    this._mqttBase = mqttBase || new MqttBase();
    this._config.pollingInterval = ProvisioningDeviceConstants.defaultPollingInterval;

    const responseHandler = (topic: string, payload: any) => {
      let payloadString: string = payload.toString('ascii');
      debug('message received on ' + topic);
      debug('request payload is: ' + payloadString);

      /* Codes_SRS_NODE_PROVISIONING_MQTT_18_010: [ When waiting for responses, `registrationRequest` shall watch for messages with a topic named $dps/registrations/res//?$rid=.] */
      /* Codes_SRS_NODE_PROVISIONING_MQTT_18_024: [ When waiting for responses, `queryOperationStatus` shall watch for messages with a topic named $dps/registrations/res//?$rid=.] */
      let match = topic.match(/^\$dps\/registrations\/res\/(.*)\/\?(.*)$/);

      if (!!match && match.length === 3) {
        let queryParameters = queryString.parse(match[2]);
        if (queryParameters.$rid) {
          let rid: string = queryParameters.$rid as string;
          if (this._operations[rid]) {

_onEnter: (callback, err) => {
            this._mqtt.removeListener('message', messageHandler);
            if (callback) {
              callback(err);
            } else if (err) {
              this.emit('error', translateError(err));
            }
          },
          subscribe: (callback) => this._fsm.transition('subscribingToResponseTopic', callback),

this._fsm.handle('connect', (err) => {
              if (err) {
                /*Codes_SRS_NODE_DEVICE_MQTT_16_024: [The `sendEvent` method shall call its callback with an `Error` that has been translated using the `translateError` method if the `MqttBase` object fails to establish a connection.]*/
                sendEventCallback(translateError(err));
              } else {
                this._fsm.handle('sendEvent', topic, payload, options, sendEventCallback);
              }
            });
          },

this._mqtt.publish(topic, body.toString(), { qos: 0, retain: false }, (err, puback) => {
      if (err) {
        /*Codes_SRS_NODE_DEVICE_MQTT_TWIN_CLIENT_16_008: [If an error happen while publishing the request message, the `callback` shall be called with the translated version of this error obtained by using the `translateError` method of the `azure-iot-mqtt-base` package.]*/
        /*Codes_SRS_NODE_DEVICE_MQTT_TWIN_CLIENT_16_018: [If an error happen while publishing the request message, the `callback` shall be called with the translated version of this error obtained by using the `translateError` method of the `azure-iot-mqtt-base` package.]*/
        delete this._pendingTwinRequests[requestId];
        callback(translateError(err));
      } else {
        debug('twin request sent: ' + puback);
      }
    });
  }