Node.js introduction

1. Node.js 1, 2, 3
Knowing the usage of Node.js
Simple web server for example
Zack Pan / StarNight

2. 目錄
1. 參考資料
2. 前人智慧的啟發
3. 安裝Node.js
4. 用 ...

3. 參考資料
Manuel Kiessling, Node入門
http://www.nodebeginner.org/index-zh-tw.html
Node.js Official Site
http://nodejs.org/
本slide可以說是Node入門的讀完心得

4. 前人智慧的啟發
Web Server
Apache, lighttpd, Nginx ...
Functions (Apache for example)
virtual hosts, proxy, CGI ...
CGI / FastCGI
CGI, Perl, PHP, Python, Ruby ...

5. Apache Httpd
是我最熟悉的Web Server
它有很多功能，沒有做不到的事
所以它很肥大
縮減功能，拿掉不必要的，可以更快
As Simple As Better!!!

6. 我想要極致效能
1. Apache掛Fast-cgi → PHP快 Python快 ...
2. Apache掛CGI → Binary program
3. Jserv, 以 GDB 重新學習 C 語言程式設計
http://blog.linux.org.tw/~jserv/archives/2010/04/_gdb_c_1.html
4. 自己用C刻一個有HTTP Server功能的程式

7. 慣C自幹Web Server
要先喀完
RFC2616
Hypertext Transfer Protocol -- HTTP/1.1
http://www.w3.org/Protocols/rfc2616/rfc2616.html
所以我就放棄這麼做了！

8. 直到有一天，我遇見Node.js
這樣就是一個Web Server ！！！
var http = require("http");
http.createServer(function(request, response) {
response.writeHead(200, {"Content-Type": "text/plain"});
response.write("Hello World");
response.end();
}).listen(8888);

9. Wiki Node.js
Node.js is a packaged compilation of Google's
V8 JavaScript engine.
Node.js is a server-side software system
designed for writing scalable Internet
applications, notably web servers. Programs
are written on the server side in JavaScript,
using event-driven, asynchronous I/O to
minimize overhead and maximize scalability.

10. 安裝Node.js
http://nodejs.org

11. Hello World!
helloworld.js
debug message to STDOUT
console.log("Hello World!");
node helloworld.js

12. 一個Web Server要
● 一個會HTTP 1.1的Web server
● 看得懂URL
● 要可以根據URL做不同的動作
● 最起碼可以接GET和POST的資料
● 可以根據Request，有相對應的HTTP
Response給Client

13. 一個簡單的Web Server by Node.js
var http = require("http"); 宣告要使用http模組
建立一HTTP Server
http.createServer( function(request, response) {
response.writeHead(200, {"Content-Type": "text/plain"});
response.write("Hello World");
response.end(); Callback Function
}).listen(8888);
要該HTTP Server監聽8888 port

14. 善用Node.js Docs
http://nodejs.org/api/

15. Require → #include in C
Core Modules
File Modules
Loading from node_modules Folders
http://nodejs.org/api/modules.html#modules_modules

16. 函數傳遞
javascript function除了可以傳參數，也可以傳
function，就跟C可以傳函式指標一樣
function say(word) {
console.log(word);
}
function execute(someFunction, value) {
someFunction(value);
}
execute(say, "Hello");

17. Type of function object
Function 也是 Object
ECMAScript® Language Specification
Wiki function object
Javascript typeof
認識 JavaScript 的物件導向技術

18. http module
var http = require("http");
http.createServer(function(request, response) {
response.writeHead(200, {"Content-Type": "text/plain"});
response.write("Hello World");
response.end();
}).listen(8888);
http://nodejs.org/api/http.
html#http_http_createserver_requestlistener

19. 匿名函式掛給request event執行
var http = require("http");
http.createServer(
function(request, response) {
response.writeHead(
200, {"Content-Type": "text/plain"});
response.write("Hello World");
response.end();
}).listen(8888);
http://nodejs.org/api/http.html#http_event_request

20. Node.js的特性
如同網頁瀏覽器一樣，在Node.js跑javascript的
V8 JavaScript engine是single thread。
程式碼原則是由上而下執行，因此可以寫順序式
的程式。
碰到I/O有關的程式，整個process就會被block
住，直到I/O回應執行完畢，才會往下執行。
與I/O有關的程式，要用event的概念來解決block
問題。

21. Callback function for event-driven
var http = require("http");
定義Callback function for request event
function onRequest(request, response) {
console.log("Request received.");
response.writeHead(200, {"Content-Type": "text/plain"});
response.write("Hello World");
response.end();
}
將onRequest註冊至request event
http.createServer(onRequest).listen(8888);
console.log("Server has started.");

22. Event in Node.js → Interrupt of chip
Is that right?????
Understanding the node.js
event loop

23. Arguments of the callback function
function onRequest(request, response) {
console.log("Request received.");
response.writeHead(200, {"Content-Type": "text/plain"});
response.write("Hello World");
response.end();
}
request: instance of http.IncomingMessage
response: instance of http.ServerResponse
http://nodejs.org/api/http.html#http_event_request

24. Module
將HTTP Server相關的code包裝
var http = require("http");
function onRequest(request, response) {
console.log("Request received.");
response.end("Hello World");
}
http.createServer(onRequest).listen(8888);
console.log("Server has started.");

25. mylib.js
function foo(port) {
var http = require("http");
function onRequest(request, response) {
console.log("Request received.");
response.end("Hello World");
}
http.createServer(onRequest).listen(port);
console.log("Server has started.");
}
exports.onRequest = foo;

26. server.js
var server = require("./mylib");
var linstening_port = 8888;
server.onRequest(linstening_port);

27. Create NPM package
在專案根目錄加上package.json檔
詳細項目說明https://npmjs.org/doc/json.html
Examples:
Create NPM Package – Node.js Module
NPM 套件管理工具
如何在Node.js中使用npm创建和发布一个模块

28. 以上是Node.js基本認識
其餘請繼續Node入門

29. Node.js還可以
Java script 全面逆襲！使用
node.js 打造桌面環境！
Fred @ COSCUP 2012
http://www.slideshare.
net/cfsghost/java-script-nodejs