Node JS Context Issue

Asked Nov 27 '18 at 12:29

Active Jul 15 '21 at 11:35

Viewed 31 times

I have some code in my controller like following

const express = require('express');
const AuthService = require('../../services/auth');

let router = express.Router();

router.get('/login', AuthService.login);

Now when i call login method in my services, and call another method from inside login method like.

class Authentication {

  login (req, res) {
    this.notify();
    res.send({message: 'login method'});
  }

  notify () {
    console.log('this is just a notification method.');
  }
}

module.exports = new Authentication();

I get following error.

TypeError: Cannot read property 'notify' of undefined

I know it's context issue, But i don't know how to fix it.

edited Jul 15 '21 at 11:35

Wenfang Du

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asked Nov 27 '18 at 12:29

pawanpandey392

Isn't it `res.end();` instead of `res.send();`? – Sv443 Nov 27 '18 at 12:31
Send also works here. But it's not the real problem. – pawanpandey392 Nov 27 '18 at 12:31
var self = this; self.notify(); try this. – Sameer Nov 27 '18 at 12:33
(TL;DR of the duplicate: replace `AuthService.login` with `AuthService.login.bind(AuthService)`) – Joe Clay Nov 27 '18 at 12:34
@SameerAhmad It also doesn't work. – pawanpandey392 Nov 27 '18 at 12:35
@JoeClay I know binding can solve this issue, but i wanna know if i need to do this for each route? – pawanpandey392 Nov 27 '18 at 12:37
just use arrow functions or bind. And yes, you have to do it for every middleware that requires the right context – Marcos Casagrande Nov 27 '18 at 12:58

Node JS Context Issue

0 Answers0