2

I am working on an Angular(frontend) and NodeJS(APIs) application. I want to schedule email on particular dates without any external call. I explored node-schedule. But how should I ensure that it runs forever in my NodeJs APIs? Like where should I put the code - in app.js or give it a route?

Divesh Soni
  • 61
  • 1
  • 4
  • 8

5 Answers5

5

You are on the right track. You have to use cron service for this. And node-schedule is a good choice for this.

So first, make a file named email-service.js.

Inside that put your logic.

email-service.js

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

var sendEmail = node.scheduleJob('0 6 * * *', function(){
   console.log('Starting..');
   init(); // write your logic here to send email
});

function init() {
  console.log('Your logic goes here.');
}

module.exports = {
    cronService: cronService
}

app.js

In the app.js import email-service.js.

const emailService = require('email-service')

emailService.sendEmail.start(); // start service..

You can schedule a cron accordingly. Below is the format of the cron.

The cron format consists of:

*    *    *    *    *    *
┬    ┬    ┬    ┬    ┬    ┬
│    │    │    │    │    │
│    │    │    │    │    └ day of week (0 - 7) (0 or 7 is Sun)
│    │    │    │    └───── month (1 - 12)
│    │    │    └────────── day of month (1 - 31)
│    │    └─────────────── hour (0 - 23)
│    └──────────────────── minute (0 - 59)
└───────────────────────── second (0 - 59, OPTIONAL)
Surjeet Bhadauriya
  • 6,755
  • 3
  • 34
  • 52
  • Hi thanks for the help. I am using new Date() as the parameter of schedulejob and the year, month and date value are fetched from database. Doing this results in mails being sent continuously. But if I pass direct values in new Date() it works as intended. Please Help. – Divesh Soni Mar 19 '19 at 10:50
  • Also please explain the exports – Divesh Soni Mar 19 '19 at 11:11
  • exports is an object. So it exposes whatever you assigned to it as a module. – Surjeet Bhadauriya Mar 19 '19 at 12:57
  • I am working on how to make it cron work dynamic. Once I am done with it, I'll post here. – Surjeet Bhadauriya Mar 19 '19 at 12:58
  • @SurjeetBhadauriya hey man can you please take a look at here: https://stackoverflow.com/questions/66987333/start-stop-cronjob-on-button-click-in-nodejs-express-app . I badly need help with this. – Zak Apr 07 '21 at 16:58
  • Hey @SurjeetBhadauriya, do you have any clue how to handle the timezone conversation? Currently, if I choose in my front-end (Vuejs) a date when an email to be sent, it will automatically convert it in UTC on the back-end. This means, that the message will be sent earlier (in my case 2 hours earlier, cause I am in EEST) and that is not correct. – Vitomir Feb 03 '23 at 12:59
4

One more thing, if the application is restarts then your schedule event get cancelled. so it might be a good approach if you save your event in a db and marked them complete or incomplete. And re-schedule your incomplete events at the restart of the application.

I use this to make sure all events runs.

Pankaj Jindal
  • 175
  • 1
  • 2
  • 10
1

Sounds like something you can achieve with nodeCron.

You may have a look at the answer here too

You can shcedule your scheduler to execute on a specific time like 

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

var j = schedule.scheduleJob('42 * * * *', function(){
  console.log('The answer to life, the universe, and everything!');
});

The example above is from node-cron npm page. Please have a look and their github for better understanding.

Nuru Salihu
  • 4,756
  • 17
  • 65
  • 116
0

You can use node-schedule node module, it's well documented.

Priyank
  • 1
  • 1
    please provide more detail, maybe an example. OP would find your answer of little help, he already mentioned he is considering node-schedule. – AJS Mar 18 '19 at 05:58
0

We use PM2 (https://pm2.io/runtime/) - It's a process manager that keeps your process running and has configuration that will allow you to schedule a node job to run according to a cron schedule. There's alot more to it, but if you're looking to improve the operation of your API, this tool is really good - and free.

CvZ
  • 26
  • 3