CODEWITHSUNDEEP
angularjsnode.jsexpressmongoose
adnpwd
adnpwd

Reputation: 111

How to use req.params in express 4 with Mongoose

I'm stuck in using req.params.id to execute a query with Mongoose. I use Angular but the problem don't come from here.

I just put the code that concern my server and my route files

routes.js

var Product = require('./models/product');     // My Mongoose model
var express        = require('express');

var router = express.Router(); // Do I really need that ?

// function to retrieve ALL employees (working)

function getEmployees(res){
    Employee.find(function(err, employees) {
    if (err)
        return res.send(err)
    res.json(employees);
    });
};

// function to retrieve ONE employee (not working)

function getEmployeeByID(req,res){
    var query  = Employee.where({ _id: req.params.id });
    query.findOne(function (err, employee) {
        if (err)
            return res.send(err)
        res.json(employee);
        });
    };

module.exports = function(app) {

// !!!!!!!!!!!  PROBLEM IS HERE !!!!!!!!!!!!!!!
app.get('/employees/:employee_id', function(req, res) {
    getEmployeeByID(res);
});


// ALL IS WORKING HERE
app.get('/employees', function(req, res) {
    getEmployees(res);
});

app.post('/employees', function(req, res) {
    Employee.create({
        firstname : req.body.firstname,
        lastname : req.body.lastname,
        age : req.body.age,
        dept : req.body.dept,
        done : false
    }, function(err) {
        if (err)
            res.send(err);
        getEmployees(res);
    });
});


app.delete('/employees/:employee_id', function(req, res) {
    Employee.remove({
        _id : req.params.employee_id
    }, function(err) {
        if (err)
            res.send(err);
        getEmployees(res);
    });
});


app.use('/', router);
module.exports = router;

}; // end module.exports

Then I have my server file

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


var db = require('./config/db');
mongoose.connect(db.url);

var port = process.env.PORT || 8080; // set our port

var router = express.Router();

// application -------------------------------------------------------------
router.get('/', function(req, res) {
    res.sendfile('./public/index.html');
});


app.use(bodyParser.json()); // parse application/json 
app.use(bodyParser.json({ type: 'application/vnd.api+json' }));
app.use(bodyParser.urlencoded({ extended: true })); 
app.use(methodOverride('X-HTTP-Method-Override')); 
app.use(express.static(__dirname + '/public')); 

// routes ==================================================
require('./app/routes')(app); // pass our application into our routes

app.listen(port);   
module.exports = app;

The problem is that when I land on the employees page, I have an error :
GET http://localhost:8080/employees/undefined 500 (Internal Server Error)
It's normal since I've not clicked yet an employee so no ID.

BUT, still, even with a click on one employee, it's ID is not retrieved. I mean, the URL is changed with /employees/employee_id but it won't find the ID in the function getEmployeeByID. In Terminal all the console.log give UNDEFINED even after clicking on ONE employee.

I tried many examples and rode the Docs on Express 4 but can't find what's wrong.

Thanks you if you can help.

Upvotes: 2

Views: 10325

Answers (2)

user12038667
user12038667

Reputation:

I solved this problem.

userController.js

exports.getUser  = (req, res) => {

const  _id  =  req.params.id        

UserModel.findById(_id).then((user) => {

if (!user) {

return  res.status(404).send()

}         

res.send(user)

}).catch((error) => {

res.status(500).send(error)

})    
}

router.js

router.get('/users/:id', userController.getUser)

Upvotes: 1

Ozk
Ozk

Reputation: 191

You have an error in the way you call the getEmployeeByID function. The function signature expects req then res, but you are sending only res to it, which will be wrongly treated as req inside the function.

Also, you should refer to the param with the name you gave it, meaning req.params.employee_id.

Now you should actually use the router instead of app which is the more classic way of doing it in Express4.

function getEmployeeByID(req, res){
    var query  = Employee.where({ _id: req.params.employee_id }); // <-- Use the correct param name
    query.findOne(function (err, employee) {
        if (err)
            return res.send(err)
        res.json(employee);
        });
    };

module.exports = function(app) {

// User router instead of app
router.get('/employees/:employee_id', function(req, res) {
    getEmployeeByID(req, res); // <-- sending both req and res to the function
});

I've never used moongoose (am a mongodb native driver user) so can't comment on that part of the code.

Upvotes: 2

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