节点应用程序：尝试从 firebird.attach 例程中发布 MQTT 消息

Question

所以我有一个 firebird.attach 成功运行的例程

res.render('success');
client.publish('time', 'test');
console.log(`MQTT sent`)

但我正在尝试从其中发布上述 mqtt 消息。

client.on('connect', function () {
  client.subscribe('presence', function (err) {
    if (!err) {
      client.publish('test', 'Hello')
    }
  })
})

以上消息有效并被发送和接收，它在 firebird.attach 代码块之外独立存在，所以我想知道是否有可能运行 mqtt 代码在 firebird.attach 块内？ console.log 消息（MQTT 发送）确实出现了，所以我很困惑。

谢谢

代码在这里：

require('dotenv').config()

// Express intialization
const express = require('express')
const app = express()
app.set('view engine', 'pug')
const port = 4010
var moment = require('moment'); // require
app.use(express.static('public'))


// Firebird initialization
var firebird = require('node-firebird')
var options = {}
options.host = process.env.HOST
options.port = process.env.PORT
options.database = process.env.DB_PATH
options.user = process.env.DB_USER
options.password = process.env.DB_PASSWORD

var mqtt = require('mqtt')
var client  = mqtt.connect('mqtt://192.168.1.1')

client.on('connect', function () {
  client.subscribe('presence', function (err) {
    if (!err) {
      client.publish('presence', 'Hello mqtt')
    }
  })
})

client.on('message', function (topic, message) {
  // message is Buffer
  console.log(message.toString())
  client.end()
})


firebird.attach(options, function(err, db) {
    if(err) throw err;
    
    app.get('/', (req, res) => {
        db.query('SELECT opid, name FROM PXOPS WHERE OPID NOT IN (1, -1, 10, 14)', function(err, rows) {
          if(err) throw err;
  
          res.render('index', { operators: rows });
        });
      })
  
      app.get('/clock/:id', (req, res) => {
          if(req.params.id) {
              db.query('SELECT opid, name FROM PXOPS WHERE OPID = ' + req.params.id, function(err, operator_row = []) {
                  if(operator_row.length === 1)
                  {
                      var clockedIn = false;
                      db.query('SELECT FIRST 1 * FROM PXATTENDEPXNTS WHERE OPID = ' + req.params.id + ' AND DATETIME >= \'' + moment().startOf('day').format('YYYY-MM-DD HH:mm:ss') + '\' ORDER BY DATETIME DESC', function(err, last_row) {
                          console.log(last_row);
              if(err) throw err;
                          if(last_row.length === 1 && last_row[0].EPXNTTYPE === 0) clockedIn = true;
                      
                          if(clockedIn)
                          {
                              db.query('SELECT FIRST 10 * FROM PXATTENDEPXNTS WHERE OPID = ' + req.params.id + ' AND DATETIME >= \'' + moment().startOf('day').format('YYYY-MM-DD HH:mm:ss') + '\'', function(err, today_rows) {
                                  totalMinutes = 0;
                console.log(today_rows);
                                  today_rows.push({ DATETIME: moment().format('YYYY-MM-DD HH:mm:ss')});
                                  splitRows = today_rows.reduce(function(result, value, index, array) {
                                      if (index % 2 === 0)
                                        result.push(array.slice(index, index + 2));
                                      return result;
                                  }, []);
  
                                  splitRows.forEach(pair => {
                                      totalMinutes += Math.round(moment.duration(moment(pair[1].DATETIME).diff(moment(pair[0].DATETIME))).asMinutes());
                                  });
  
                                  console.log(totalMinutes);
  
                                  minuteString = null;
                                  hours = 0;
                                  remainingMinutes = 0;
                                  if(totalMinutes > 60)
                                  {
                                      hours = Math.floor(totalMinutes / 60);
                                      remainingMinutes = totalMinutes - (hours * 60);
                                  }
  
                                  if(hours > 0 && remainingMinutes > 0)
                                  {
                                      minuteString = hours + ' hours and ' + remainingMinutes + ' minutes'
                                  }
                                  else if(hours > 0 && remainingMinutes === 0)
                                  {
                                      minuteString = hours + ' hours';
                                  }
                                  else {
                                      minuteString = totalMinutes + ' minutes';
                                  }
  
                                  res.render('clock', { operator: operator_row[0], working_string: minuteString, clockedIn: clockedIn });
  
                              });
                          }
                          else
                          {
                              res.render('clock', {operator: operator_row[0], clockedIn: clockedIn})
                          }
                      });
  
                  }
              });
          }
      })
  
      app.get('/clock-in/:id', (req, res) => {
          db.query('SELECT opid, name FROM PXOPS WHERE OPID = ' + req.params.id, function(err, rows) {
  
              if(rows.length === 0) 
              {
                  res.render('error');
              }
  
              // Check if he's already clocked in
              db.query('SELECT FIRST 1 OPID FROM PXATTENDEPXNTS WHERE OPID = ' + req.params.id + ' ORDER BY ATTENDEPXNTID DESC', function(err, rows) {
                  if(err) throw err;
  
                  if(rows.length === 1 && rows[0].EPXNTTYPE == 0)
                  {
                      res.render('error');
                  }
                  else
                  {
                      db.query('SELECT FIRST 1 ATTENDEPXNTID FROM PXATTENDEPXNTS ORDER BY ATTENDEPXNTID DESC', function(err, rows) {
                          lastID = 0;
                          if(rows.length === 1)
                          {
                              lastID = rows[0].ATTENDEPXNTID;
                          }
  
                          db.query('INSERT INTO PXATTENDEPXNTS (ATTENDEPXNTID, OPID, DATETIME, EPXNTTYPE, SCANNEDSTR, BRANCHID, CHANGED_FLAG, DEPTID) VALUES (' + (lastID + 1) + ','+ req.params.id +', \'' + moment().format('YYYY-MM-DD HH:mm:ss') + '\', 0, null, 1, 1, 0)', function(err, rows) {
                              if(err) throw err;
  
                              res.render('success');
                                                            client.publish('timeclock', 'clocked in');
                                                            console.log(`MQTT sent`)
                          });
                      });
                  }
              });
          });
        })
  
        app.get('/clock-out/:id', (req, res) => {
          db.query('SELECT opid, name FROM PXOPS WHERE OPID = ' + req.params.id, function(err, rows) {
  
              if(rows.length === 0) 
              {
                  res.render('error');
              }
  
              // Check if he's already clocked out
              db.query('SELECT FIRST 1 OPID FROM PXATTENDEPXNTS WHERE OPID = ' + req.params.id + ' ORDER BY ATTENDEPXNTID DESC', function(err, rows) {
                  if(err) throw err;
  
                  if(rows.length === 1 && rows[0].EPXNTTYPE == 1)
                  {
                      res.render('error');
                  }
                  else
                  {
                      db.query('SELECT FIRST 1 ATTENDEPXNTID FROM PXATTENDEPXNTS ORDER BY ATTENDEPXNTID DESC', function(err, rows) {
                          lastID = 0;
                          if(rows.length === 1)
                          {
                              lastID = rows[0].ATTENDEPXNTID;
                          }
  
                          db.query('INSERT INTO PXATTENDEPXNTS (ATTENDEPXNTID, OPID, DATETIME, EPXNTTYPE, SCANNEDSTR, BRANCHID, CHANGED_FLAG, DEPTID) VALUES (' + (lastID + 1) + ','+ req.params.id +', \''+ moment().format('YYYY-MM-DD HH:mm:ss') +'\', 1, null, 1, 1, 0)', function(err, rows) {
                              if(err) throw err;
  
                              res.render('success')
                          });
                      });
                  }
              });
          });
        })
})


app.listen(port, () => {
  console.log(`App listening at http://localhost:${port}`)
})

Answer 1

on message 回调中的

client.end() 将关闭 MQTT 客户端。因此，您在 connect 回调中发布的消息将导致客户端立即退出。

（如果订阅主题，客户端会收到自己发布的消息，这可以使用 MQTT v5 iirc 进行更改，但需要明确设置）

节点应用程序：尝试从 firebird.attach 例程中发布 MQTT 消息

Node App: Trying to publish an MQTT message from within a firebird.attach routine

node.js

mqtt

mqtt.js