js-notes.md

Template String

var arr = ['Foo', 'Bar']

console.log(`Olá
    ${arr[0]}
    e
    ${arr[1]}`)

Map

var studios = [
    '20th Century Fox',
    'Warner Bros.',
    'Walt Disney Pictues'
]

var lengths = studios.map( s => s.length)

console.log(lengths)

Síncrono

console.log('1');
t();
console.log('3');
function t() {
    console.log('2');
}

assincrono

console.log('1');
t();
console.log('3');
function t() {
    setTimeout(() => {
        console.log('2');
    }, 10);
}

Server http

let http = require('http');
let server = http.createServer(function (request, response) {
  response.writeHead(200, {'Content-Type': 'text/plain'});

  if(request.url === '/') {
    response.end('Hello World\n');
  } else if(request.url === '/contato') {
    response.end('wbrunom@gmail.com\n');
  } else {
    response.end('Not found');
  }
});
server.listen(1337, '127.0.0.1');
console.log('Server running at http://127.0.0.1:1337/');

Promise

// new Promise(function(resolve, reject) {
//
// });

// const wait = time => new Promise(resolve => setTimeout(resolve, time));
//
// wait(1000).then(() => console.log('Hello!'));

const wait = function(time) {

    return new Promise(function(resolve) {

        return setTimeout(resolve, time)

    });

};

// wait(2000)
//     .then(() => console.log( 'Foo BAR' ))


wait(2000)
    // onFulfilled() can return a new promise `x`
    .then(() => new Promise(res => res('foo')))
    // the next promise will assume the state of `x`
    .then(a => a)
    // Above we returned the unwrapped value of `x`
    // so `.then()` above returns a fulfilled promise
    // with that value:
    .then(b => console.log(b)) // 'Foo'
    // Note that `null` is a valid promise value:
    .then(() => null)
    .then(c => console.log(c)) // null
    // The following error is not reported yet:
    .then(() => {throw new Error('foo');})
    // Instead, the returned promise is rejected
    // with the error as the reason:
    .then(
        // Nothing is logged here due to the error above:
        d => console.log(`d: ${ d }`),
        // Now we handle the error (rejection reason)
        e => console.log(e)
    ) // [Error: foo]
    // Wiith the previous exceptions handled, we can continue:
    .then(f => console.log(`f: ${ f }`)) // f: undefined
    // The following doesn't log. e was already handled.
    // so this handler doesn't get called:
    .catch(e => console.log(e))
    .then(() => { throw new Error('bar'); })
    // When a promise is rejected, success handlers get skipped.
    // Nothing logs here because of the 'bar' exception:
    .then(g => console.log(`g: ${ g }`))
    .catch(h => console.log(h)) // [Error: bar]

Bit operator

var noTry = false ? 'do' : 'do not';

console.log(noTry);

var noTry2 = false || 'do nottt'

console.log(noTry2);

Object Create

BattleDroid.prototype = Object.create(Droid.prototype);

Net

const net = require('net');

const server = net.createServer((socket) => {
  socket.end('goodbye\n');
}).on('error', (err) => {
  // handle errors here
  throw err;
});

// grab an arbitrary unused port.
server.listen(() => {
  console.log('opened server on', server.address());
});

Lorem ipsum

#!/usr/bin/env node
/**
 * loremipsum.js
 *
 * Faz uma requisiçâo na API `http://loripsum.net/api/`
 * e grava um arquivo com o nome e quantidade
 * de parágrafos espificados
 *
 * William Bruno, Maio de 2015
 */

var http = require('http');
var fs = require('fs');
var fileName = String(process.argv[2] || '').replace(/[^a-z0-9\.]/gi, '');
var quantityOfParagraphs = String(process.argv[3] || '').replace(/[^\d]/g, '');
const USAGE = 'Uso: node loremipsum.js {nomeArquivo} {quantidadeParágrafos}';

if (!fileName || !quantityOfParagraphs) {
    return console.log(USAGE);
}

http.get(`http://loripsum.net/api/${quantityOfParagraphs}`, function(res){
    var text = '';

    res.on('data', function(chunk) {
        text += chunk;
    });

    res.on('end', function() {
        fs.writeFile(fileName, text, function() {
            console.log(`Arquivo ${fileName} pronto`);
        });
    });
}).on('error', function(e) {
    console.log('Got error: ' + e.message);
});

Loop while

var arr =   ['Foo', 'Bar'],
    i   =   0,
    max =   arr.length;

while (i < max) {
    console.log( arr[i] );
    i++;
}

Loop map

var arr = ['Foo', 'Bar'];

arr.map(function(x) {
    console.log(x);
});

Loop for

var arr = ['Foo', 'Bar'];

for (var i = 0, max = arr.length; i < max; i++) {
    console.log(arr[i]);
}

process.argv / stdout

process.stdout.write('Han Solo\n');

// process.argv.forEach(function(arg) {
//     console.log(arg);
// });

// for(arg of process.argv) {
//     console.log(arg);
// }

// process.argv.map(arg => console.log(arg))

console.log(process.argv);

for of / for in

var arr = ['Foo', 'Bar'];

for(x of arr){
    console.log(x);
}

for(x in arr){
    console.log(x);
}

Double exclamation

// converte o valor pra seu booleano

console.log( !!'' );

console.log( !!'foo' );

console.log( !!0 );

console.log( !!1 );

Currying

/*

var bye = function(str1) {
    return function(str2) {
        return `${str1} ${str2}`;
    }
};

var good = bye('Good');
var greet = good('Bye');

console.log(greet);

*/

function currier(fn) {
    var args = Array.prototype.slice.call(arguments, 1);

    // console.log(args);
    // console.log(arguments);

    return function() {
        console.log(arguments);
        return fn.apply(this, args.concat(Array.prototype.slice.call(arguments, 0)));
    }
}

var bye = function(str1, str2) {
    return `${str1} ${str2}`;
};

var good = currier(bye, 'Good');

console.log(
    good('Bye!')
);

Chat TCP

// 'use-strict'
//
// let net = require('net')
// let chatServer = net.createServer()
// let clientList = []
//
// let removeClient = () => client.splice(client.indexOf(5), 1)
// let broadcast = () => {
// 	for(var i = clientList.length -1; i >= 0; i-- ) {
// 		if(client !== client[i]) {
// 			clientList[i].write(message)
// 		}
// 	}
// }
//
// chatServer.on('connection', client => {
// 	client.write(`Hi guest !\n`)
// 	clientList.push(client)
// 	client.on('data', data => {
// 		console.log(data, client)
// 	})
// 	client.on('error', err => {
// 		console.log(err);
// 	})
// 	client.on('end', removeClient)
// })
//
// chatServer.listen(9000)

'use strict';

const net         = require('net');
const chatServer  = net.createServer();
const clientList  = [];


let broadcast = function (message, client) {
  for (let i = clientList.length - 1; i >= 0; i--) {
    if (client !== clientList[i]) {
      clientList[i].write(message);
    }
  }
};

chatServer.on('connection', function (client) {
  client.write('Hi guest' + '!\n');
  clientList.push(client);

  client.on('data', function (data) {
    broadcast(data, client);
  });
  client.on('end', function () {
    console.log('client', clientList.indexOf(client));

    clientList.splice(clientList.indexOf(client), 1);
  });
  client.on('error', function(err) {
    console.log(err);
  });
});

chatServer.listen(9000);

Arrow scope

var arr = ['Foo', 'Bar'];

arr.map(function(x) {
    console.log(this);
});

---

design pattern Observer Syntatic sugar heraça classica

livro: principios de orientacao a objetos em js

JS tem seis tipos primitivos String Number Boolean Null Undefined Symbol

Douglas Crockford: Javascript: A menos ententida lingaguem de programacao do globo

programacao funcional

publicar module no npm

REPL - console do node js

Array.reduce

node inspector

editorConfig.org

hoisting

funcoes sao objetos de primeira classe

IIFE

nodejs --v8-options|grep 'harmony'

Singleton

pagina 26 ha um erro arr ou invez de max

promises - promisesaplus.com Promise, Promise.all()

template string - interpolar variaveis

chmod +x loremipsum.js

how to deal with debug module and env vars

https://nodejs.org/api/net.html

DAO - data access ObjectId

orm

Squelize

waterline

mongosse

dbs with nodejs: oracledb, mysql, sqlserver, redis

express generator

exec()

json web tokens

salt (decodificacao)