A Javascript noob's guide to Node + Express + Compound.JS

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This blog represents all the wrong doings of a first time programmer into javascript domain

To start with lets beging with a short explaination of these technologies

Node:		The very basic layer required by you to create a website
		Thats the best thing about it, imagine an app working without any middle-ware, thus improving the performance
	
Express:	An upper layer for Node to make things a little easier and more abstract

Compound:	The top layer built specially to be used over Express. It is down right translation of RoR
		It adds a much higher level of abstraction into the app


The application which we will be developing will go step by step

1st:	A Sample app just using Node.js

2nd:	A Sample app using Node.js + Express.js

3rd:	Using The templating Library Jade

4th:	Links and instructions to understand Compound.js

5th:	Development of a sample login app with apt utilization of MVC architectures

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1st: 

Read through node.js API and developed a sample "hello world" app

It is very important to refer to the documentation again and again, most of the solutions to problems are 
found in the docs

	http://nodejs.org/api/all.html

Now an issue will be there: accepting request data

	the request data(req) we assumed was not the request from http.IncomingMessage,
	it was for the request data sent from one server to another
	hence in the confusion we faced such issues (listed below )
	( 
	  the api wants the request to read through complete data before posting the response
	  below is the code
	  if request variable is omitted the code works fine.
	)
	
var http = require("http"),
   url = require("url");
http.createServer(function (request, response) {
      var _get = url.parse(request.url, true).query;
      response.writeHead(200, {
         'Content-Type': 'text/plain'
      });
      console.log( _get );
      response.end('Here is your data: ' + _get['data']);
}).listen(8080);

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2nd:

Now lets start with Express.js, it is a web application framework for node
	http://expressjs.com
Read Express.js API and the guide

Develop form with get and post methods
	var express = require('express');
	var app = express();

	app.listen(3001);
	app.get('/',function(req,res){
	res.send('<form method="post" action="users"><label>Name</label><input type="text" id="name" name="name"></p><input type="submit" value="Submit" /></form>');
	})

	app.post('/users', function(req, res){
	app.use(express.bodyParser());
	console.log(req.body);
	res.send(req.body.name);
	});	


Experiments with Sessions
	eg: http://blog.modulus.io/nodejs-and-express-sessions

	Read about sessions
	got stuck at the use of repetitive html codes as res.send can not be used twice as every time we use it, it overwrites the previous data on the html, thus a complete html template will be required to post various data
	Solution : Templates
	Start reading Jade.

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3rd:

	    JADE
	jade-lang.com

Jade is a templating library which translates to HTML 5

For newbies, a template is kind of a board on which a programmer defines the position where he wants the data to be displayed
It is usefull as the template can be used again and again
and templating brings a sense of modularity to the code

Make an app with maintaining session and routing between urls and using jade templates

Any random variable can be declared with   "req.session.[variable]"   to store a session variable, So if you want to store count 
or a string or anything required by you, it can be added to the req.session

app.bodyParser is already mentioned in default declarations
	so we dont need to rewrite it when parsing post data from the form post request.

Here is what I have developed ->
	https://github.com/devrishik/eashmart/blob/master/

useful links
	https://github.com/shapeshed/express_example
	http://naltatis.github.io/jade-syntax-docs/
	http://blog.modulus.io/nodejs-and-express-sessions

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4th:

		Compound.JS
	http://compoundjs.com/docs/

Now lets start with compound.js
to get a quick overview just read through 	

	https://github.com/compoundjs/guides/blob/master/basics/crash-course.md

Reading the API will be simple, but then trying out the sample app will create problems

Issues:

compound uses EJS as a default library for templating, we have to use jade
	so following 	
		http://tysonjs.com/blog/how-do-yo-make-a-compoundjs-app#.UcKjjvEW3Zg
	
	will help, but not to much.

	After sirfing through blogs and google groups for some time you will get the solution
	so saving on your time, here it is ->

		compound init [project_name] --tpl jade --db mysql

	This commands initiates the development of a project and specifying the template 'jade' and database 'mysql'
	
		cd [project_name]

		compound generater crud .............

	Here we use generater CRUD ( Create Read Update Delete ) will generate an app for you
	
		compound generater crud name 
		
	another error, after using the crud generator for generating your sample app, all the views
	will be compiled in EJS.


Start reading up on a sample app 
	http://nyukapiszka.wordpress.com/2013/02/16/node-js-mvc-frameworks-getting-started-with-compoundjs/

Amit gave us a huge tip.... "follow RoR blog tutorial to learn about MVC and compound.js"
	http://guides.rubyonrails.org/getting_started.html

things learnt:
	there are two types of models - non persistent defined in app/models
					and
					persistent defined in the database schema   /config/database.js

					https://github.com/compoundjs/guides/blob/master/basics/elements-explained.md

	Update the schema required in db/schema.js

	We have to make the database ourselves ..... i know thats a dumb thing not to know :D but please forgive my novice

	Delete the non persistent model from app/model as this constricts the app from connecting to the persistent model

After all this, you expect the app to run... well it will run but still no List created

	then with all my genius and "persistent" hinting by Amit I realized... there is no table     :-)

		compound db migrate

	Before executing this command follow these steps
	
		go to config/database.js
			
			specify the database your going to use and the driver as 'mysql' under the development
				driver: 'mysql',
				host: 'localhost',
				port: 3306,
				username: 'root',
				password: '',
				database: 'db_dev'

		open mysql
				mysql -u root
				create database db_dev;

		go to schema.js
			
			check out your schema, which is the table which will be created in your database
			This schema also represents the persisitent model for your program

	Now execute this command
	learn from http://stackoverflow.com/questions/16618094/compound-db-update-migrate-not-working-in-mysql

	This command updates your table
		
		Perform migrate on
		 - mysql
		1
		DROP TABLE IF EXISTS `List` [89 ms]
		CREATE TABLE `List` (
		  `id` INT(11) NOT NULL AUTO_INCREMENT PRIMARY KEY,
		  `dev` VARCHAR(255) NULL
		) [156 ms]

Now, the app works persistently  :P

Here is the complete source ->
	https://github.com/devrishik/To-Do-List/tree/master/todo-list-app

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5th:

	Creating a Sample App in Compound.JS

task : Start preparing the login/signup app

lets start with reading up on models and how to play with data

	In simple words, model is that part of MVC framework where all the data manipulations come

1st : Defining unique key or a primary key

		in order to make a login app, its common sense that you would want your username to be unique
		
		inumerable examples available for mongoose db schema
		hours of searching =    https://github.com/jugglingdb/mysql-adapter/issues/5

		property('name', {index: { kind: 'unique' ,required: true} });

		We have to specify the kind and required attributes inside the index in this very format

		this takes care of the duplication and empty fields you would require for your primary field
		as the controller instantiates the sql to write data and error will be returned for an invalid entry
		which will be handled by the event handler

		code :=

			this.list.updateAttributes(body.List, function (err) {
				respondTo(function (format) {
				    format.json(function () {
					if (err) {
					    send({code: 500, error: list && list.errors || err});
					} else {
					    send({code: 200, data: list});
					}
				    });
				    format.html(function () {
					if (!err) {
					    flash('info', 'List updated');
					    redirect(path_to.list(list));
					} else {
					    flash('error', 'List can not be updated');
					    render('edit');
					}
				    });
				});
			    });

2nd :	Use Hooks	http://jugglingdb.co/hooks.3.html
		
		It is best to use the beforeCreate hook as it will be called on both edit and create

		code :=

			module.exports = function (compound, List) {
			List.beforeSave = function(next){

				console.log("before");
				next();
			}
			};

3rd :	Bcrypt encryption algorithm

		https://github.com/ncb000gt/node.bcrypt.js/

	The basic idea is to never save a password as String into the database
	therefore, whenever saving a password we hash it using Bcrypt
	and when comparing passwords we just have to compare the hashs

Here is the compiled version :)

https://github.com/devrishik/Basic_Login_App