how to make module asynchronous in javascript

Question

I am new in javascript. I have simple module which sent email using sendgrid :

    // using SendGrid's v3 Node.js Library
// https://github.com/sendgrid/sendgrid-nodejs
var helper = require('sendgrid').mail;
var fromEmail = new helper.Email('test@test.com');
var toEmail = new helper.Email('sample@sample.com');
var subject = 'Sending with SendGrid is Fun';
var content = new helper.Content('text/plain', 'and easy to do anywhere, even with Node.js');


var mail = new helper.Mail(fromEmail, subject, toEmail, content);

var sg = require('sendgrid')("**********************");
var request = sg.emptyRequest({
  method: 'POST',
  path: '/v3/mail/send',
  body: mail.toJSON()
});

sg.API(request, function (error, response) {
  if (error) {
    console.log('Error response received');
  }
  console.log(response.statusCode);
  console.log(response.body);
  console.log(response.headers);
});

now I want to call this module in an asynchronous way. should I implement promise or use async, await?

There is an another hint (if you use Javascript on a browser): https://www.w3schools.com/html/html5_webworkers.asp — mpasko256, Aug 18 '17 at 14:34
Yes, you should implement a promise *and* then use `async`/`await` syntax to use it. — Bergi, Aug 18 '17 at 17:39

score 1 · Accepted Answer · answered Aug 19 '17 at 00:44

According to sendgrid's docs, promises are already implemented, which makes this a little easier since you can just return that promise from your module. For example if you just want to use that promise you can:

//mymodule.js

var helper = require('sendgrid').mail;
var fromEmail = new helper.Email('test@test.com');
var toEmail = new helper.Email('sample@sample.com');
var subject = 'Sending with SendGrid is Fun';
var content = new helper.Content('text/plain', 'and easy to do anywhere, even with Node.js');



module.exports = function(from, subject, to, content){
    var mail = new helper.Mail(fromEmail, subject, toEmail, content);

    var sg = require('sendgrid')("**********************");
    var request = sg.emptyRequest({
    method: 'POST',
    path: '/v3/mail/send',
    body: mail.toJSON()
    });

    return sg.API(request)
}

Now you can simply use it like:

mail = require('./mymodule')

mail("from@example.com", "subject", "to@example.com", content)
.then(function(response) {
    // use response.body etc
})

how to make module asynchronous in javascript

1 Answers1