Idea for a queued MQTT publishing in MJS

handle_queue.js

// sketch to publish MQTT message with queue, if MQTT is not connected
// when connected, on every try to pubslish a message, eventually queued
// messages will be published fist

let mqtt_test = {
  _queue: [],           // a simple filo queue by array
  _mqttConected: false, // will be set in other function by event
  
  publishMsgQueued: function (topic, payload) {
    if (this.handleQueue(topic, payload)) {
      this.publishMsg(topic, payload);
    }
  },

  publishMsg: function (topic, payload) {
    // add your publishing code here ...
  },
  
  handleQueue: function (topic, payload) {
      let result = true;

      if (this._mqttConected === false) {
        this._queue.push(JSON.parse('{ "payload": "' + payload + '", "topic": "' + topic + '"}'));
        Log.error('Error publishing, trying again later ...');
        result = false;
      } else if (this._queue.length > 0) {
        // if there is a queue, process these entries first
        let pubObj = this._queue.shift();
        while (pubObj !== null) {
          Log.debug('Processing queue entry ...');
          this.publishMsg(pubObj.topic, pubObj.payload);
          pubObj = this._queue.shift();
        }
      }
      return result;
    }
}