NODEJS(5)Expressjs and CRUD

NODEJS(5)Expressjs and CRUD

1. Play with Expressjs
>npm -version
1.4.9

>grunt -version
grunt-cli v0.1.11

Check the latest expressJS
>npm info express version
npmhttpGEThttps://registry.npmjs.org/expressnpmhttp304https://registry.npmjs.org/express 4.2.0

Then I put package.json there as follow>
{ 
     "name": "hello", 
     "description": "first demo app", 
     "version": "0.0.1", 
     "private": true, 
     "dependencies": {   
          "express" : "4.2.0" 
     }
}

Use command to install all the dependency
>npm install

And >npm ls will list all the dependencies.

And the simplest app.js should be as follow>
var express = require('express');
var app = express();

app.get('/hello.txt', function(req, res){
     res.send('Hello Sillycat');
});

app.listen(3000);
console.log('Listening on port 3000');

And there a plenty of examples here
https://github.com/visionmedia/express/tree/master/examples

We can open the debug MODE
>DEBUG=express:* node app.js
https://github.com/visionmedia/debug

2. Using ExpressJS to build CRUD
>sudo npm install -g express
>sudo npm install -g express-generator
This will install some core Express functionality right into my Node installation.

Generate the Project
>express userlist
Or
>express —css stylus userlist

Go to that directory, >npm install will install all the dependencies.

Run the application will be as follow:
>DEBUG=userlist ./bin/www

Some key parts are as follow>
app.js Prepare the Monk Connection
// Mongodb Client Configuration
var mongo = require('mongodb’);
var monk = require('monk');
var db = monk('127.0.0.1:27010/userlist');

And Before we add the router, we need to expose  the db client to the req
// make db available
app.use(function(req,res,next){
    req.db = db;
    next();
});

app.use('/', indexs);
app.use('/users', users);

Here is the service/mapping/control part, index.js which control all the router and http Method Mapping.
var express = require('express');
var debug = require('debug')('http');
var router = express.Router();

/* GET home page. */
router.get('/', function(req, res) {
  res.render('index', { title: 'Express' });
});

/* GET users listing. */
router.get('/userlist', function(req, res) {
  var db = req.db;
  var users = db.get("users");
  users.find({},{},function(e,docs){
       res.render('userlist', {
            "userlist" : docs
       });
  });
});

router.get('/newuser', function(req, res){
     res.render('newuser', {title: 'Add New User' });
});

/* POST to Add User Service */
router.post('/adduser', function(req, res) {
    var db = req.db;
    // Get our form values. These rely on the "name" attributes
    var userName = req.body.userName;
    var userEmail = req.body.userEmail;
    // Set our collection
    var users = db.get('users');
    // Submit to the DB
    users.insert({
        "userName" : userName,
        "userEmail" : userEmail
    }, function (err, doc) {
        if (err) {
            res.send("There was a problem adding the information to the database.");
        }
        else {
            res.location("userlist");
            res.redirect("userlist");
        }
    });
});

router.get('/deluser/:id', function(req, res){
     debug("receive the id=" + req.params.id);

     var db = req.db;
     var id = req.params.id;
     var users = db.get('users');

     users.remove({_id: id}, function(err){
          if(err){
               res.send("Some Problem during deleting the user with id = " + id);
          }
          else {
               res.location("/userlist");
               res.redirect("/userlist");
          }
     })
});

module.exports = router;

And here is the jade part, I did not put much time on jade, actually my server side only provide REST API via JSON Format. 
I plan to not use jade to construct my HTML.

userlist.jade is as follow>
extends layout

block content
     h1.
          User List
     ul
          each user, i in userlist
               li
                    a(href="mailto:#{user.userEmail}")= user.userName
                    ||||
                    a(href="/deluser/#{user._id}") Delete

the newuser.jade is as follow>
extends layout

block content
     h1= title
     form#formAddUser(name="adduser",method="post",action="/adduser")
          input#inputUserName(type="text", placeholder="user name", name="userName")
          input#inputUserEmail(type="text", placeholder="user email", name="userEmail")
          button#btnSubmit(type="submit") submit

All the related codes and implementation are under easynodejs/userlist.

References:
http://cwbuecheler.com/web/tutorials/2013/node-express-mongo/
http://cwbuecheler.com/web/tutorials/2014/restful-web-app-node-express-mongodb/
https://github.com/cwbuecheler/node-tutorial-2-restful-app
http://www.vincent-durmont.com/2013/11/29/first-rest-api-with-node-express-monk-and-mongodb.html

http://expressjs.com/
http://sillycat.iteye.com/blog/2010679

Monk document
https://github.com/LearnBoost/monk

Deployment
forever
http://blog.nodejitsu.com/keep-a-nodejs-server-up-with-forever/
https://github.com/nodejitsu/forever
http://stackoverflow.com/questions/18008620/node-js-express-js-app-only-works-on-port-3000