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.

I solved this problem by following the details included in [this Stack Overflow response](https://stackoverflow.com/a/69828684/14193416) — C RICH, Nov 03 '21 at 16:52

Subburaj · Accepted Answer · 2016-01-18T11:45:57.000

57

Instead of this:

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

You try for:

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

edited Jan 18 '16 at 11:45

answered Jan 18 '16 at 11:36

Subburaj

5,114
10
44
87

5

@KevinAB Hi could you explain why this won't work: `app.post('/user/all',Controller.Create);` – btzr Jul 28 '17 at 03:58
I don't see the problem with this: `Controller.Create = function(req, res) { ... }` – btzr Jul 28 '17 at 04:00
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 :) – Cyclotron3x3 Jun 09 '18 at 21:12
1

can u explain this?? – Gaurav Aggarwal Jan 31 '19 at 08:26
2

@Subburaj 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 – Saad Abbasi Jul 14 '20 at 19:28
@btzr if we use `'/user/all/', Controller.Create` we are not even passing the req,res parameters. – mr.loop Jun 03 '21 at 05:46
This is not the correct answer. – 0xAnon Sep 18 '22 at 16:41
check middleware names correctly referenced or not – MUHAMMAD SHAHID RAFI C P Jan 03 '23 at 13:25

score 38 · Answer 2 · answered Jun 24 '19 at 15:29

38

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.

answered Jun 24 '19 at 15:29

Ignacio Ara

2,476
2
26
37

3

You're right it has nothing to do with the real problem. For me I was exporting the function wrongly. – Merunas Grincalaitis Aug 24 '19 at 23:37
2

For me, it was where I forgot to rename the new function in the router when I copy-pasted. – cst1992 Nov 09 '20 at 08:31
1

Absolutely right! For me, I created `model.updateOne` but added `model.update` to the router. – maswerdna May 21 '22 at 04:43

score 14 · Answer 3 · answered Nov 22 '19 at 16:58

14

You are only missing

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

answered Nov 22 '19 at 16:58

Godstime

365
7
14

1

That is the exact issue with this particular error type. There's an export missing, probably in the controller file. – Dženis H. Feb 22 '20 at 01:27
1

"It's the little things that kill." — Bush, "Little Things" – Jamie Jul 02 '20 at 15:06
1

One thing to add here: *Check for function names when copy-pasting*! – cst1992 Nov 09 '20 at 08:31

score 5 · Answer 4 · answered Nov 08 '20 at 06:54

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.

score 4 · Answer 5 · answered Dec 01 '21 at 09:46

4

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

answered Dec 01 '21 at 09:46

Snow

411
5
8

score 3 · Answer 6 · answered Feb 28 '21 at 00:19

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

score 3 · Answer 7 · answered Jun 19 '22 at 03:26

3

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')

answered Jun 19 '22 at 03:26

Ali Bin Naseer

113
2
8

score 2 · Answer 8 · answered Jul 02 '20 at 06:25

2

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');

answered Jul 02 '20 at 06:25

Nurudin Lartey

71
1
3

score 2 · Answer 9 · answered Oct 23 '20 at 23:23

2

For me it was a simple, stupid typo.

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

answered Oct 23 '20 at 23:23

user1118374

164
3
12

score 2 · Answer 10 · answered Apr 16 '21 at 18:27

2

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.

answered Apr 16 '21 at 18:27

Ali Muhammad Khowaja

425
5
9

score 1 · Answer 11 · answered Feb 08 '21 at 14:08

1

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.

answered Feb 08 '21 at 14:08

LachoTomov

3,312
30
42

score 1 · Answer 12 · answered May 17 '21 at 08:09

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.

score 1 · Answer 13 · answered Jun 03 '22 at 08:43

1

In my case I didnot exported the function of controller

answered Jun 03 '22 at 08:43

Mahin qureshi

21
3

This answer is more suitable as a comment, try enhancing your answer by providing an example on how to solve OP's problem. (e.g. how to export a function and which function exactly.) – posixpascal Jun 03 '22 at 13:14

score 0 · Answer 14 · edited Nov 02 '20 at 03:14

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

score 0 · Answer 15 · edited May 12 '21 at 03:06

0

I resolve this problem adding

module.exports = new ExampleController();

just adding new.

edited May 12 '21 at 03:06

Lin Du

88,126
95
281
483

answered May 11 '21 at 19:26

Antonio Fernando

1

score 0 · Answer 16 · answered Sep 11 '21 at 09:25

0

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);

answered Sep 11 '21 at 09:25

Osman Faruk

11
2

score 0 · Answer 17 · edited Dec 03 '21 at 02:54

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.

score 0 · Answer 18 · answered Feb 24 '22 at 17:39

0

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

answered Feb 24 '22 at 17:39

Tharindu Nilakshana

31
2

score 0 · Answer 19 · answered Mar 07 '22 at 11:59

I stuck for an hour then I resolved these issues, whenever you got these errors then you should understand that you have created a different name convention in admin and AdminMediator. I solved these issues, when I clicked on the required APIs in admin, it doesn't direct me to the desired API in AdminMediator, then I understood why this error occurs.

Thanks

score 0 · Answer 20 · edited Apr 28 '22 at 01:32

0

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

For Example:

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

edited Apr 28 '22 at 01:32

Jakub Kurdziel

3,216
2
12
22

answered Apr 22 '22 at 11:08

Siddharth181

1
2

score 0 · Answer 21 · edited May 22 '22 at 13:01

0

In route.js, instead of importing:

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

Try this:

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

edited May 22 '22 at 13:01

Tyler2P

2,324
26
22
31

answered May 22 '22 at 10:26

Uttam Shrestha

1

score 0 · Answer 22 · answered Jun 15 '22 at 07:12

0

It's also quite possible you have a route that is defined but not being used, try looking for that route and deleting both the route and controller

answered Jun 15 '22 at 07:12

Micheal Macaulay

1

1

Your answer could be improved with additional supporting information. Please [edit] to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers [in the help center](/help/how-to-answer). – Y. Gherbi Jun 16 '22 at 11:07

score 0 · Answer 23 · answered Sep 08 '22 at 07:33

0

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

Remove/comment all other routes which you haven't yet defined (Let's say in your controller).

In my case it worked.

answered Sep 08 '22 at 07:33

Sigma

1

This does not provide an answer to the question. Once you have sufficient [reputation](https://stackoverflow.com/help/whats-reputation) you will be able to [comment on any post](https://stackoverflow.com/help/privileges/comment); instead, [provide answers that don't require clarification from the asker](https://meta.stackexchange.com/questions/214173/why-do-i-need-50-reputation-to-comment-what-can-i-do-instead). - [From Review](/review/late-answers/32671503) – kavigun Sep 15 '22 at 05:49

score 0 · Answer 24 · answered Nov 13 '22 at 04:06

0

the error I was getting is :

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

and this was my file: userController file from where I was importing

the mistake I was doing at that time is importing 2 entities from a file separately instead of de-structuring

this will fix my error

answered Nov 13 '22 at 04:06

shubham yaduvanshi

11
2

1

Thanks for sharing your experience! It would even be more helpful to provide the code in text form, not in form of images / screenshots. – Ingo Steinke Nov 15 '22 at 15:53

Indratej Reddy · Answer 25 · 2022-11-21T16:32:11.467

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 :)

score 0 · Answer 26 · edited Jun 25 '23 at 23:18

0

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

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

edited Jun 25 '23 at 23:18

J. Murray

1,460
11
19

answered Jun 22 '23 at 11:28

Ajay Nadar

1
2

score 0 · Answer 27 · answered Jul 04 '23 at 11:00

0

You might have misspelled controller.create in controller or routes file

answered Jul 04 '23 at 11:00

Rizwan Syal

19
4

score -1 · Answer 28 · answered Nov 23 '19 at 12:07

-1

yes Subburaj is correct, Implement in app.js

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

this could be solve the problem

answered Nov 23 '19 at 12:07

Kamalesh Sivaraj

61
9

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

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