Error: .post() requires callback functions but got a [object Undefined] not working

Question

there are several issues with the same theme, but I could not solve my problem.

Error: Route.post() requires callback functions but got a [object Undefined]
at Route.(anonymous function) [as post] (/home/kevin/proyectoApp/node_modules/express/lib/router/route.js:196:15)
at EventEmitter.app.(anonymous function) [as post] (/home/kevin/proyectoApp/node_modules/express/lib/application.js:481:19)
at module.exports (/home/kevin/proyectoApp/app/rutas.js:7:5)
at Object.<anonymous> (/home/kevin/proyectoApp/index.js:21:26)
at Module._compile (module.js:398:26)
at Object.Module._extensions..js (module.js:405:10)
at Module.load (module.js:344:32)
at Function.Module._load (module.js:301:12)
at Function.Module.runMain (module.js:430:10)
at startup (node.js:141:18)
at node.js:1003:3

Index.js

var express=require('express');
var app=express();
var morgan=require('morgan')
var mongoose=require('mongoose');
var bodyParser=require('body-parser');
var methodOverride=require('method-override');

mongoose.connect('mongodb://localhost/local');


app.use(express.static(__dirname+'/public'));
app.use(morgan('dev'));
app.use(bodyParser.urlencoded({ extended: false }))
app.use(bodyParser.json())


//Endpoints
require('./app/rutas.js')(app);


var server=app.listen(3001,function () {
var host = "localhost";
var port = server.address().port;

console.log('servidor escuchando en http://%s:%s', host, port);});
module.exports=app;

rutas.js

var Controller=require('./controller.js');
var User=require('./models/user.js');

module.exports=function(app){

app.get('/user/all',Controller.Read);

app.put('/user/all/:todo_id',Controller.Update);

app.post('/user/all',Controller.Create);

app.delete('/user/all/todo_id',Controller.Delete);


app.get('/',function(req,res){
console.log("Este si carga");
res.sendFile('./public/index.html');
});
 }

user.js

var mongoose=require('mongoose');
var Schema=mongoose.Schema;

var Schemausuario=new Schema({
nombre:String,
apellido:String,
username:{type:String,requiere:true,unique:true}
});

var User=mongoose.model('User',Schemausuario);

module.exports=User;

controller.js

var User=require('./models/user.js');

var Create=function (req,res){
var nombre=req.body.nombre;
var apellido=req.body.apellido;
var nick=req.body.username;
console.log("Datos"+nombre+apellido+nick);
User.create({
nombre:nombre,
apellido:apellido,
username:nick

},function(err,usr){

if( err) console.log("Error al crear el usuario");
else{
    console.log("Usuario creado correctamente");
}
});

User.find({},function(err,user){
if(err) console.log("Hay un error al buscar los usuarios");
else{
    console.log("Los usuarios encontrados son "+user)
       res.json(user);
            }        
});

};


var Read=function (req,res){

User.find({},function(err,user){
if(err) return console.log("error="+err);
else{
       res.json(user);
            }        
});
};



var Update=function(req,res){
User.update( {_id : req.params.todo_id},
                {$set:{nombre : req.body.nombre,apellido:    req.body.apellido, username: req.body.username}}, 
                function(err, persona) {
                    if (err)
                        res.send(err);

            // Obtine y devuelve todas las personas tras crear una de     ellas
            User.find(function(err, user) {
                if (err)
                    res.send("Ha habido un error"+err)
                console.log("Se va a enviar "+persona)
                res.json(user);
            });
        });
};


var Delete=function(req,res){

  User.remove({
    _id: req.params.todo_id
}, function(err, todo) {
    if(err){
        res.send("Hay un error hdp"+err);
    }
    else{
        console.log("Usuario eliminado correctamente")
    }
    });

    User.find({},function(err, todos) {
        if(err){
            res.send(err);
        }
        res.json(todos);
    });
};

module.exports={
Create:Create,
Update:Update,
Read:Read,
Delete:Delete
}

I use the version "express", "^ 4.13.3"

can you help me? thanks. any other details that I'll upload it finds omitted. any other details that I'll upload it finds omitted.

Erine

I solved this problem by following the details included in this Stack Overflow response – Myna

Answer 1

Instead of this:

app.post('/user/all',Controller.Create);

You try for:

app.post('/user/all', function(req, res){
  Controller.Create
});

Wardmote

@KevinAB Hi could you explain why this won't work: app.post('/user/all',Controller.Create); – Confess

I don't see the problem with this: Controller.Create = function(req, res) { ... } – Confess

I wonder how Controller. Create worked in the 2nd case given that the Create function in controller.js expects request, response object to be passed as params. Shouldn't this be Controller.Create(req,res). I might be missing some internal functioning here though :) – Birdcage

@Wardmote by using your solution that error was fixed, but other functionality does not work.there was some error in exporting and importing, now that's work fine with Controller.create. Thanks – Saltant

@Confess if we use '/user/all/', Controller.Create we are not even passing the req,res parameters. – Nur

Answer 2

In my case it was because I had a misspelling between the router and controller file. Check both so that they match, the error .POST() requires callback functions but got a [object Undefined] has nothing to do with the real problem.

Cleat

You're right it has nothing to do with the real problem. For me I was exporting the function wrongly. – Wentworth

For me, it was where I forgot to rename the new function in the router when I copy-pasted. – Ube

Absolutely right! For me, I created model.updateOne but added model.update to the router. – Presume

Answer 3

You are only missing

module.exports = app, or whatever you are exporting. This happened to me many times.

Protectorate

That is the exact issue with this particular error type. There's an export missing, probably in the controller file. – Reactor

"It's the little things that kill." — Bush, "Little Things" – Winze

One thing to add here: Check for function names when copy-pasting! – Ube

Answer 4

I got this error when I declared the function in routes but forgot to define it in the controller.

Spleeny

Answer 5

You want to be sure to check that your spellings are correct for the export and the import. Also make sure your middleware are properly exported and imported.

From the code you are sharing, you should export each middleware individually as exports.Create, exports.Update etc. Setting up your export this way will make it possible to access it the way you are currently accessing it view the Controller variable in your rutas.js file.

Panter

Answer 6

In my case, I was Destructuring the export while importing.

if you did module.exports = something, you need to do const something = require('./dir') But if you did module.exports = { something }, you need to do const { something } = require('./dir')

Dorothi

Answer 7

Another case, which I ran into. I was importing from the controller a method called

const { createTrade } = require(...)

But I also had

exports.createTrade = async (..) => { ...

In another part of this file I referenced the createTrade from the import but it was confused about using the exports.createTrade or the imported one. I had to switch to

const controller = require(...)

controller.createTrade

Paraplegia

Answer 8

Always ensure the export name is the same as the import name

//Function Exported
exports.isAuthenticatedUser = catchAsyncErrors(async(req, res, next) => {
}


//Function Imported
const {isAuthenticatedUser} = require('../middlewares/auth');

Irv

Answer 9

For me it was a simple, stupid typo.

I had module.export = { instead of module.exports = {

Chihli

Answer 10

I was having the same issue the way i resolved it was i did comment every post command and then i tested all the post commands one by one and in the 2nd last command when i checked routuer there was a typo error and that was that function wasnt called.

Mattins

Answer 11

In my case this was due to a circular dependency in the file - file A imported functions from file B, but file B imported functions from file A.

Natatorial

Answer 12

In my case, I've encountered this error when I have deleted a function in my controller.js file but forgot to remove it in the router definition.

for eg,

router.get('/', controller.getUsers);

So, in the above code, I've deleted that getUsers() function in the controller.js file but I still used it in the route definition. So after removing this useless route the problem gets solved. Hope this error helps someone.

Torrential

Answer 13

This error usually comes when you mistakenly import functions in the wrong way, or may be a spelling mistake Both the controller and the route are in some trouble.

I encountered this when I was exporting a function from the controller which was all good.

exports.addCategory = (req,res) => {}

but when I was importing it in the routes I was doing

const addCategory = require('../Controllers/Category')

instead

const {addCategory) = require('../Controllers/Category')

you see that curly braces around addCategory while importing So, I was importing the entire function, which was wrong

Relive

Answer 14

I resolve this problem adding

module.exports = new ExampleController();

just adding new.

Ppi

Answer 15

do not export your controller like this

module.exports.createPost = () => {..}

instead of export like this

module.exports = {
    createPost,
}

and import the controller like this,

postRouter.post("/createNew_post", postControllers.createPost);

Spaceport

Answer 16

I had the same error, this was my mistake:

Controller:

module.exports = cargarArchivo;

Route:

const { cargarArchivo } = require('../controllers/uploads');
const { Router } = require('express');
const router = Router();

router.post( '/', cargarArchivo )

Error:

Error: Route.post() requires a callback function but got a [object Object]

SOLUTION: In the controller change:

module.exports = cargarArchivo;

For:

module.exports = {
  cargarArchivo
}

The problems is I'm exporting the constant as a constant instead exporting it as a property in the controller, then importing it as a property. It has to match both ways.

Willingham

Answer 17

Rename the Controller Method Name Work For me. Try it also

Tenorite

Answer 18

In my case in the controllers the function login was not defined, but trying to access

For Example:

router.post('/user/login', userController.login)

Brigade

Answer 19

In route.js, instead of importing:

**var Controller=require('./controller.js');

Try this:

var { Controller } = require('./contoller.js');

Mountebank

Answer 20

This is my code I got the same issues and I found 3 valid solutions if your using module.exports.

when I tried to print the imports from my controller I found it is return empty object {} . so the solutions are

Solution 1: Cross check the name of the files where you exporting and where you importing it in your path.

Solution 2: use require.resolve("...your import path").

example for solution 1 :

before:

const express = require("express");
const router = express.Router();
const createToDo = require("../controllers/CreateToDoController")
router.get("/",(req,res)=>{
    res.send("<h1>Welcome to Homepage</h1>");
})
console.log('todo iss', createToDo);
router.post("/createtodo",(req,res)=>createToDo(res,req));
module.exports = router;

after:

const express = require("express");
const router = express.Router();
const createToDo = require.resolve("../controllers/CreateToDoController")
router.get("/",(req,res)=>{
    res.send("<h1>Welcome to Homepage</h1>");
})
console.log('todo iss', createToDo);
router.post("/createtodo",(req,res)=>createToDo(res,req));
module.exports = router;

Solution 3:

Wrap the controller function inside callback. Better to use arrow function to make it one line:

here is the code before change: Todocontroller.js

//importing model
const toDoModel = require('../models/ToDoModel');

//creating controller function
const createToDoController = async (req,res)=>{
    try{
    const {title,toDoTasks} = req.body;

    if(!title) //input validation
    { 
        throw new Error("Please provide the title");
    }
    const newToDo = await toDoModel.create({ title, tasks:toDoTasks?toDoTasks:[] });
    res.status(201).json({
        success: true,
        message: "User Created Successfully",
        newToDo,
      });
    }
    catch(err){
        res.status(500).json({
            success: false,
            message: "Unable to perform create operation",
            error: err
        })
        res.send(err.message);
    } 

}
module.exports = createToDoController;

router.js

const express = require("express");
const router = express.Router();
const createToDo = require("../controllers/CreateToDoController")
router.get("/",(req,res)=>{
    res.send("<h1>Welcome to Homepage</h1>");
})
console.log(`todo iss ${createToDo}`);
router.post("/createtodo",createToDo);
module.exports = router;

I have change the line from router.post("/createtodo",createToDo); to router.post("/createtodo",(req,res)=>createToDo(res,req));

I don't understand why this is happening but yeah this is only solution working for me. if you got better solutions please mention in discussions :)

Superload

Answer 21

In my case, adding {} around the importing variable was sufficient to solve the error:

const {registerUser}=require("../controllers/userController");

Biplane

Answer 22

My issue turned out to be that some of my callbacks were async functions, which evaluate to a Promise, not a function. The solution was to wrap the async code in a non-async function call. I did this in the module.exports object:

module.exports = {
  myCallback: (req, res) => { myCallbackAsync(req, res); },
  // ...
}

but it could also be done within the function itself by wrapping the async code in an async sub-function or IIFE and calling that within the callback.

Mascarenas

Answer 23

yes Subburaj is correct, Implement in app.js

app.post('/sign', function (req, res) {
    LoginController.authenticate
});

this could be solve the problem

Astrodynamics