Taha EL BOUFFI thelbouffi

Node.js - npm Cheat Sheet

(Full description and list of commands at - https://npmjs.org/doc/index.html)

##List of less common (however useful) NPM commands

######Prepand ./bin to your $PATH Make sure to export your local $PATH and prepand relative ./node_modules/.bin/:

Install mongodb
sudo apt-get install mongodb

Acess mongodb.service and insert the configuration code
cd /lib/systemd/system
sudo vim mongodb.service

[Unit]
Description=High-performance, schema-free document-oriented database
Documentation=man:mongod(1)

	// The JavaScript functions always return something. If you don't specify something to return in the function then
	// 'undefined' is returned by default

	// So, console.log() will always return 'undefined' on node and chrome because the function doesn't return anything
	let x;
	let y = 3;

	console.log(y);
	// this console.log will return
	// 3

	// in exports_method.js
	let add = (a, b) => a + b;
	exports.add = add; // OR module.exports.add = add;

	// in module_exports.js
	let add = (a, b) => a + b;
	module.exports = add;


	// in caller.js

	// in express we can pass a callback to another callback using next
	// for example if we need to choose between two response (if condition is made res.send else res.send) to do that we need to pass next()
	// callback to else in our middleware

	// in the auth_middleware.js
	let authenticated = false;
	let requireLogin = (req, res, next) => {
	if (!authenticated) {
	res.send('not logged in'); // res.redirect('/login');
	console.log('not logged');

	The MIT License (MIT)

	Copyright (c) 2015 Justin Perry

	Permission is hereby granted, free of charge, to any person obtaining a copy of
	this software and associated documentation files (the "Software"), to deal in
	the Software without restriction, including without limitation the rights to
	use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
	the Software, and to permit persons to whom the Software is furnished to do so,
	subject to the following conditions:

	{
	"activites" : "activitiesTable",
	"tasks" : {
	"-KfbYYnJDdJ1IfQ4D6bl" : {
	"firstname" : "palani",
	"lastname" : "just lastname updated"
	},
	"-KfpLsLVH59MpKXDdYVm" : {
	"firstname" : "palaniraja",
	"lastname" : "raja"

	// Node.js CheatSheet.
	// Download the Node.js source code or a pre-built installer for your platform, and start developing today.
	// Download: http://nodejs.org/download/
	// More: http://nodejs.org/api/all.html


	// 0. Synopsis.
	// http://nodejs.org/api/synopsis.html

	JavaScript is untyped, meaning that we can pass around data and objects as we want.
	We can write code that calls methods that don't exist on an object, or variables that we don't have.
	These problems are hard to discover when you are writing code and it can lead to unstable code,
	and doing big changes of your code can become very difficult and risky as you don't immediately see if your changes
	conflicts with the rest of the code.

	TypeScript is mainly about adding types to JavaScript. That means that TypeScript requires you to accurately
	describe the format of your objects and your data. When you do that, that means that the compiler can investigate
	your code and discover errors. It can see that you are trying to call a function that does not exist or use a variable
	that is not accessible in the current scope.

	var vehicle = function(ty) {
	this.type=ty;
	}
	vehicle.prototype.ride = function() {
	console.log('I am riding a ', this.type);
	}
	var newRebuild = function(constructor){
	var obj = {};
	Object.setPrototypeOf(obj, constructor.prototype);
	var arArgs = Array.from(arguments).slice(1);