how to require a class in node.js - node.js

Question

my code that works..
var express=require("express"),
app=express();
class bar {
constructor()
{
this.user_name=null;
this.user_surname=null;
this.user_age=null;
}
name(user_name) {
this.user_name=user_name;
return this;
}
surname(user_surname) {
this.user_surname=user_surname;
return this;
}
age(user_age) {
this.user_age=user_age;
return this;
}
get(callback) {
var list ={};
list.uname=this.user_name;
list.usurname=this.user_surname;
list.uage=this.user_age;
callback(list);
}
}
app.get("/liste/:ext",function(req,res){
var ext=req.params.ext;
res.setHeader('Content-Type', 'application/json');
if(ext==1)
{
var newbar=new bar();
newbar.name("alex").surname("broox").age(32).get(function(result){
res.json({data:result})
})
}
if(ext==2)
{
var newbar=new bar();
newbar.name("alex2").get(function(result){
res.json({data:result})
})
}
})
app.listen(4000,function(log){
console.log("listening")
})
but..following code does not work.. with require that class from other file..
test.js
module.exports = {
class bar {
constructor()
{
this.user_name=null;
this.user_surname=null;
this.user_age=null;
}
name(user_name) {
this.user_name=user_name;
return this;
}
surname(user_surname) {
this.user_surname=user_surname;
return this;
}
age(user_age) {
this.user_age=user_age;
return this;
}
get(callback) {
var list ={};
list.uname=this.user_name;
list.usurname=this.user_surname;
list.uage=this.user_age;
callback(list);
}
}
};
app.js file.. with require that class
var express=require("express"),
app=express();
require("./test")
app.get("/liste/:ext",function(req,res){
var ext=req.params.ext;
res.setHeader('Content-Type', 'application/json');
if(ext==1)
{
var newbar=new bar();
newbar.name("alex").surname("broox").age(32).get(function(result){
res.json({data:result})
})
}
if(ext==2)
{
newbar.name("alex2").get(function(result){
res.json({data:result})
})
}
})
app.listen(4000,function(log){
console.log("listening")
})
but why does not it work...please help me..above code that works but this code that does not work..

Answer 1

When exporting classes in node you need to define the class first, then export the class using module.exports followed by the name of the class you wish to export.
// test.js
class Bar {
constructor() {
this.user_name=null;
this.user_surname=null;
this.user_age=null;
}
name(user_name) {
this.user_name=user_name;
return this;
}
surname(user_surname) {
this.user_surname=user_surname;
return this;
}
age(user_age) {
this.user_age=user_age;
return this;
}
get(callback) {
var list ={};
list.uname=this.user_name;
list.usurname=this.user_surname;
list.uage=this.user_age;
callback(list);
}
}
module.exports = Bar
From there you can just require the file and grab the class as such.
var Bar = require('./test');
var bar = new Bar();

Answer 2

test.js isn't valid syntax - you shouldn't have your entire file wrapped in braces like that. module.exports is just a variable which you set; if you want to export bar, set it to bar:
class bar {
...
}
module.exports = bar;
Additionally, you need to assign the result of your require call in app.js.
var bar = require("./test");
(On a slightly pedantic note - it's more idiomatic to captialize your class names!)

Answer 3

hello again #DominicValenciana
test.js
class bar {
constructor()
{
this.user_name=null;
this.user_surname=null;
this.user_age=null;
}
name(user_name) {
this.user_name=user_name;
return this;
}
surname(user_surname) {
this.user_surname=user_surname;
return this;
}
age(user_age) {
this.user_age=user_age;
return this;
}
get(callback) {
var list ={};
list.uname=this.user_name;
list.usurname=this.user_surname;
list.uage=this.user_age;
callback(list);
}
}
module.exports = bar;
app.js
var express=require("express"),
app=express();
app.get("/liste/:ext",function(req,res){
var ext=req.params.ext;
res.setHeader('Content-Type', 'application/json');
if(ext==1)
{
var bar=new require('./test');
bar.name("alex").surname("broox").age(32).get(function(result){
res.json({data:result})
})
}
if(ext==2)
{
var bar=new require('./test');
bar.name("alex2").get(function(result){
res.json({data:result})
})
}
})
app.listen(4000,function(log){
console.log("listening")
})
as error : TypeError: bar.name is not a function