I am wondering how to communicate between controllers - node.js

Question

I want to invoke the user creation API after confirming the token internally in the server when I click the authentication link in the e-mail to implement the membership method using e-mail authentication.
//emailcontroller.js
router.get('/register/token', function(req, res) {
// check token
if(check(req.params.token)) {
request('http://localhost:8080/api/user', function(data) {
});
}
});
//usercontroller.js
router.post('/api/user', function(req, res) {
var user = new User();
user.userId = req.body.userId;
user.userPw = req.body.userPw;
user.save();
});
I want to invoke the user creation API after confirming the token internally in the server when I click the authentication link in email in order to implement membership method using email authentication.
As mentioned above, the email controller and the user controller are divided and each is routed. I want to modularize the code so that I want to call the existing user creation API to use it for general purpose rather than creating and exports common functions for a specific controller.
/*I do not want to implement it this way.*/
//emailController.js
router.get('/register/token', function(req, res) {
// check token
if(check(req.params.token)) {
userContoller.createUserFromEmail(userId, userPw);
}
});
//userController.js
exports.createUserFromEmail = function(userId, userPw) {
var user = new User();
user.userId = userId;
user.userPw = userPw;
user.save();
}
However, I have never seen communication between controllers in many examples. So I do not know if the way I thought was right. Rather, I think the cost of calling api internally on the server might be higher.
I want to know the correct pattern for communication between controllers. Please bear in mind that there is only a stack overflow when raising a question.

Answer 1

You got the right idea about exposing your API functionality as stand-alone functions (or classes). To avoid duplication, just call your internal methods from within your route handlers. So in your example:
router.post('/api/user', function(req, res) {
createUserFromEmail(req.body.userId, req.body.userPw);
});
In my own projects, I use classes to create my API. First I define a class with just the functionality and then I expose the methods in the route handlers:
export default class User {
read() {
}
create() {
}
update() {
}
delete() {
}
}
const user = new User();
router.get('/user/:id', (req, res) => user.read(req.params.id));
router.post('/user', (req, res) => user.create(req.body.data));
router.put('/user/:id', (req, res) => user.update(req.params.id, req.body.data));
router.delete('/user/:id', (req, res) => user.delete(req.params.id));
This should give you an idea of what you can do. You can write custom middleware and class decorators to reduce the boilerplate.

Answer 2

From your question what I understood:
You want to validate internally the token passed in query parameter, before doing anything else in the user controller.
I believe you are using express, and with express comes middlewares.
From docs:
Middleware functions are functions that have access to the request object (req), the response object (res), and the next middleware function in the application’s request-response cycle. The next middleware function is commonly denoted by a variable named next.
What I usually do and a generally good practice is, pass the token in create user api and attach to email body.
for example:
api/user?token=somerandomstringloremispum
Route file:
router.post('/user', validateEmail, userController.create);
here validateEmail is a middleware function and will be invoked before create method of userController.
Now in your validateToken method, you can simply validate your token like:
function validateEmail (req, res, next) {
if(!valid(req.query.token)) {
//return with appropriate invalid token msg using res.json() or however you like
}
// if validated call `next middleware` like so:
next();
// this will allow `create` method of userController be invoked
}