`mongolab` - getting error on post, not able to post a data - mongodb

Question

I have a account with mongolab(mlab). I am trying to post a data for the users using postman add-on from chrome browser. I am getting error always. I could not able to post a data. I have tried with other diffrent ways. but no luck.
any one help me to sort this issue?
here is my api.js :
var
User = require('../models/user'),
config = require('../../config'),
secretKey = config.secretKey;
module.exports = function( app, express ) {
var api = express.Router();
api.post('/signup', function (req, res) {
var user = new User({
name:req.body.name,
username:req.body.username,
password:req.body.password
});
user.save(function(err){
if(err){
res.send(err);
return;
}
res.json({message:'User has been Created!'});
});
});
api.get('/users', function(req, res) {
User.find({}, function( req, users){
if(err) {
res.send(err);
return;
}
res.json(users);
})
});
return api;
}
config.js :
module.exports = {
"database":"mongodb://xxx:xxxx#ds015700.mlab.com:15700/arifstory",
"port" : process.env.PORT || 3000,
"secretKey" : "YourSecretKey"
}
And the user.js :
var
mongoose = require('mongoose'),
Schema = mongoose.Schema,
bcrypt = require('bcrypt-nodejs');
var UserSchema = new Schema({
name : String,
userName:{ type:String, required:true, index : { unique: true }},
password : { type:String, required : true, select : false }
});
UserSchema.pre('save', function(next) {
var user = this;
if(!user.isModified('password')) return next();
bcrypt.hash( user.password, null, null, function(err, hash) {
if(err) return next(err);
user.password = hash;
next();
});
});
UserSchema.methods.comparePassword = function( password ) {
var user = this;
return bcrypt.compareSync(password, user.password);
}
module.exports = mongoose.model('User', UserSchema);
I really unable to understand the issue here. please any one help me?
error
{
"message": "User validation failed",
"name": "ValidationError",
"errors": {
"userName": {
"message": "Path `userName` is required.",
"name": "ValidatorError",
"properties": {
"type": "required",
"message": "Path `{PATH}` is required.",
"path": "userName"
},
"kind": "required",
"path": "userName"
},
"password": {
"message": "Path `password` is required.",
"name": "ValidatorError",
"properties": {
"type": "required",
"message": "Path `{PATH}` is required.",
"path": "password"
},
"kind": "required",
"path": "password"
}
}
}

Answer 1

The data sent from chrome could be undefined.
Print it in console by including the below 2 lines above user.save function in api.js file:
console.log(req.body.username);
console.log(req.body.password);
if it shows as undefined, then make sure to check "x-www-form-urlencoded" under "body" in Postman and provide username and password under that.