Create a Scheduled Job on Startup With Express

Question

I'm just getting into Express and have ran into an issue. I have an app serving a REST API. That is all working fine. But I wanted to add a scheduled job using node-schedule (https://www.npmjs.com/package/node-schedule). I have implemented this module:

var schedule = require('node-schedule');

var scheduler = {
    scheduleJob: function(monitor) {
        var job = schedule.scheduleJob('* * * * *', function(){
            monitor.check();
        });
        return job;
    }
}

module.exports = scheduler;

In app.js I have added the following to the bottom since I found a single stack overflow question that was similar. This did not work for me:

app.on('listening', function () {
    console.log("App started, gathering monitors");
    var allMonitors = queries.getAllMonitorsInt();
    for (var i = 0; i < allMonitors.length; i++) {
        console.log("Monitor found: " + allMonitors[i].name);
        shdlr.scheduleJob(allMonitors[i]);
    }
});

I don't even get the "App started..." log message.

Am I doing this the right way or am I way off target?

Answer 1

The scheduler should be placed inside of app.listen callback, like this:

app.listen(3000, function () {
  console.log("App started, gathering monitors");
  var allMonitors = queries.getAllMonitorsInt();
  for (var i = 0; i < allMonitors.length; i++) {
      console.log("Monitor found: " + allMonitors[i].name);
      shdlr.scheduleJob(allMonitors[i]);
  }
});

Express doesn't support listening event, see an issue.