In the file users.js I want to get code out of randomCode() to assign to the result and use it in whole endpoint '/login'.
randomCode.js
const crypto = require('crypto')
const randomCode = (callback) =>{
crypto.randomInt(100000, 999999, (err, n) => {
if (err) throw err;
callback(n);
});
}
module.exports = randomCode
users.js
require('dotenv').config()
const express = require('express')
const router = express.Router()
const randomCode = require('../controllers/randomCode')
router.get('/login', async (req, res, next)=>{
try{
//-----------------------------------------------------
randomCode((code) => {
console.log(code,'code')
})
//-----------------------------------------------------
return res.send('ok')
}
catch(error){
res.send(error)
}
})
module.exports = router;
I tried to use await but whithout results.
router.get('/login', async (req, res, next)=>{
try{
//------------------------------------------------------
const result = await randomCode((code) => {
console.log(code,'code')
})
console.log(result)
//------------------------------------------------------
return res.send('ok')
}
catch(error){
res.send(error)
}
})
There would be different approaches (especially as crypto.randomInt could be
called synchronously), but I understand you are specifically interested in how
to get a value from an asynchronous function, so I'll answer that:
const randomCode = function(){
return new Promise((resolve, reject) => {
crypto.randomInt(100000, 999999, (err, n) => {
if( err ){
reject( err );
} else {
resolve( n );
}
});
});
}
router.get('/login', async (req, res, next)=>{
try{
const code = await randomCode();
console.log(code)
return res.send('ok')
}
catch(error){
res.send(error)
}
})
In cases where you can not change the randomCode() function for some reason, you need to wrap it into a Promise, like:
const randomCodePromise = function(){
return new Promise((resolve, reject) => {
randomCode((code) => {
resolve( code );
})
});
}
(and obviously then use await randomCodePromise() instead of await randomCode())