Cannot read property 'user_first_name' of undefined

Question

I am trying to register an user with expressjs/mongoose, but I am getting the error below:

TypeError: Cannot read property 'user_first_name' of undefined
at C:\Quiz webPolitica\server.js:20:24
at Layer.handle [as handle_request] (C:\Quiz webPolitica\node_modules\express\lib\router\layer.js:95:5)
at next (C:\Quiz webPolitica\node_modules\express\lib\router\route.js:131:13)
at Route.dispatch (C:\Quiz webPolitica\node_modules\express\lib\router\route.js:112:3)
at Layer.handle [as handle_request] (C:\Quiz webPolitica\node_modules\express\lib\router\layer.js:95:5)
at C:\Quiz webPolitica\node_modules\express\lib\router\index.js:277:22
at Function.process_params (C:\Quiz webPolitica\node_modules\express\lib\router\index.js:330:12)
at next (C:\Quiz webPolitica\node_modules\express\lib\router\index.js:271:10)
at serveStatic (C:\Quiz webPolitica\node_modules\express\node_modules\serve-static\index.js:75:16)
at Layer.handle [as handle_request] (C:\Quiz webPolitica\node_modules\express\lib\router\layer.js:95:5)
at trim_prefix (C:\Quiz webPolitica\node_modules\express\lib\router\index.js:312:13)
at C:\Quiz webPolitica\node_modules\express\lib\router\index.js:280:7
at Function.process_params (C:\Quiz webPolitica\node_modules\express\lib\router\index.js:330:12)
at next (C:\Quiz webPolitica\node_modules\express\lib\router\index.js:271:10)
at expressInit (C:\Quiz webPolitica\node_modules\express\lib\middleware\init.js:33:5)
at Layer.handle [as handle_request] (C:\Quiz webPolitica\node_modules\express\lib\router\layer.js:95:5)

I've tried debugging for hours and looked up other people's problems, but I ain't getting anywhere. Any help is really appreaciated. Please see my code below:

server.js

var express = require('express');
var app = express();

app.use(express.static(__dirname + '/public'));

var mongoose = require('mongoose');
mongoose.connect('mongodb://localhost/iPolitico');

var Register_User_Schema = new mongoose.Schema({
    Firstname: { type: String, required: true },
    Lastname:  { type: String, required: true },
    Email:     { type: String, required: true, index: { unique: true } },
    Password:  { type: String, required: true }
}, {collection:"user"});

var Register_User = mongoose.model("Register_User", Register_User_Schema);

app.post('/register', function(req,res){
  new Register_User({
    Firstname: req.body.user_first_name,
    Lastname : req.body.user_last_name,
    Email    : req.body.user_email,
    Password : req.body.user_password
  }).save(function(err, doc){
    if(err){
      res.json;
    }else{
      app.use(express.static(__dirname + '/user_profile.html'));
    }
  })
});

app.get('/', function(req, res){
  //res.send('hello world');
  Register_User.find(function (err, data){
    res.json(data);
  });
});

app.listen(3000);

index.html

<form role="form" action="/register" method="POST" class="registration_form">  <!--action="javascript:;" onsubmit="register_user()"-->
    <div class="form-group">
<label class="sr-only" for="form-first-name">First name</label>
        <input type="text" name="user_first_name"  id="user_first_name" placeholder="First name..." class="form-first-name form-control" >
     </div>
     <div class="form-group">
        <label class="sr-only" for="form-last-name">Last name</label>
        <input type="text" name="user_last_name" id="user_last_name" placeholder="Last name..." class="form-last-name form-control">
     </div>
     <div class="form-group">
        <label class="sr-only" for="form-email">Email</label>
        <input type="text" name="user_email" id="user_email" placeholder="Email..." class="form-email form-control" >
     </div>
     <div class="form-group">
        <label class="sr-only" for="form-password">Senha</label>
        <input type="password" name="user_password" id="user_password" placeholder="Senha..." class="form-password form-control" >
     </div>
     <div class="form-group">
         <label class="sr-only" for="form-password">Confirmar Senha</label>
        <input type="password" name="user_confirm_password" placeholder="Confirmar Senha..." class="form-password form-control" >
    </div>
    <button type="submit">Sign me up!</button>
   </form>

As a side question. When I am done registering I want to redirect to a new page. I currently have "app.use(express.static(__dirname + '/user_profile.html'));", but I am quite sure this is not correct or half correct.

Answer 1

You error simply says that the body in req.body is null. So after some Googling Stack Overflow returned me to this question. Basically it says that:

You must use something to parse the request's body data.

That means using something like bodyParser

But as @andrea.spot mentions in the comments, ever since Express4 (which I assume you are using) the BodyParser middleware must be installed separately.

So for Express4, @Jay's answer suggests you should use the following when configuring express:

var bodyParser = require('bodyParser');
app.use(bodyParser().json());`

Also, as @Jay points out, you can install it by calling:

npm install body-parser --save

Answer 2

The req.body is actually handled by middleware in Express to convert the request data to JSON before your custom code accesses it.

Try including body-parser in your project (npm install body-parser) and adding this before your first app.post:

var bodyParser = require('body-parser');
app.use(bodyParser.json());

This will grab the request to your server, parse out the data from your POST call, and put it in a JSON object as req.body.

As for redirecting, at the end of a call just add a simple res.redirect('/newPage')