Using functions with async callback

Christian Lindgren shared this problem ago

Solved

Hi,

Problem:

We're having a situation where we want to call a function with an async callback.

The issue that arises is that the script thread terminates before the callback is executed.

Is there any way to prevent the script thread from terminating before we get the callback?

Background:

We're intending to read a collection containing phone numbers, call Twilio Api (an sms service) to send a message, and finally store the status from Twilio into another collection.

db.users.find({...}).forEach((user) => {
sendSms(user.phone, "A short message", (status) => {
db.smsDeliveries.insert(status);
});
});

Immensely thankfull for any kind of help, input or suggestion that can make us able to achieve this.

PS! This task is an ad-hoc task in our work flow, otherwise we would have done this as part of our application.

Best regards,

Christian

The same problem 0

Best Answer

qinghai (support@nosqlbooster.com) ●

Hi,

Thank you for your feedback.

MongoBooster has a build-in function await. It can await a promise or a promise array.

Please try the following code:

let birdPromise=require('bluebird');
function sendSmsAsync(phone, message){ //promiseify sendSms
return new birdPromise(function (resolve, reject) {
sendSms(phone, message, (status)=>{
resolve(status)
})
});
}
db.users.find({}).forEach((user) => {
let status=await(sendSmsAsync(user.phone, "A short message")); //await a promise
db.smsDeliveries.insert({status});
});

Replies (2)

qinghai (support@nosqlbooster.com) ● ●

Hi,

Thank you for your feedback.

MongoBooster has a build-in function await. It can await a promise or a promise array.

Please try the following code:

let birdPromise=require('bluebird');
function sendSmsAsync(phone, message){ //promiseify sendSms
return new birdPromise(function (resolve, reject) {
sendSms(phone, message, (status)=>{
resolve(status)
})
});
}
db.users.find({}).forEach((user) => {
let status=await(sendSmsAsync(user.phone, "A short message")); //await a promise
db.smsDeliveries.insert({status});
});

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Christian Lindgren ●

That was exactly what I was looking for!

Thank you for saving the day ;)

Best regards,

Christian

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