Ruby on Rails探索

kewang

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Agenda

● What is Ruby?● What is Rails?● Live DEMO● FAQ● Q&A

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What is Ruby?鑽石恆久遠，一顆就破產

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What is Ruby?

● 開放原碼、物件導向的動態直譯式程式語言● 簡單哲學、高生產力● 精巧、自然的語法● 靈感來自 Lisp, Perl, Smalltalk● 設計的目的是要讓程式設計師 Happy

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Matz說

● 一般程式語言的開發目的● 可寫出能夠高速運作的程式● 可在短期間學會寫程式● 寫一次到處都能跑● 小朋友也能輕易寫出程式

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但主張「讓寫程式更快樂」的語言卻不太常見

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Matz

Ruby is simple in appearance, but is very complex inside, just like our human body.

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Programming Language Type

● Dynamic Strong Language● Ruby● Perl● Python

● PHP is Dynamic, but is not Strong.● Java is Strong, but is not Dynamic.

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EVERYTHING IS OBJECT

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irb – Interactive Ruby

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TIOBE Ranking

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Features

● Iterator● Code block (closure)● ! and ?● Meta-programming

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Iterator

● 重複做多次類似的事情● upto, downto, step, times, collect, map, each_*,

*_each, sort...many methods

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Code block (closure)

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Code block (closure)

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Code block (closure)

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Code block (closure)

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! and ?

● ! means side-effect● ? means return Boolean

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! and ?

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Meta-programming

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RubyGems

● Ruby 的套件管理工具● 所有的 Ruby 套件都可以用 gem 安裝

● Rails● RMagick● Heroku● ...etc.

● http://rubygems.org

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Sinatra

● It's a VERY lightweight web development package● gem install sinatra● http://www.sinatrarb.com

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Hello Sinatra

● ruby myapp.rb, and open http://localhost:4567

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Hello Parameter

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Sinatra - XDite如是說

使用 Sinatra 的目的並不是用來開發那些巨型的 Web application ，而是搭造那些小型的應用程式或者 API 介面。這樣做有些什麼好處呢？

如果你只是想寫一支小型程式，或者開發API ，並不需要使用 Rails 這麼複雜 ( 或肥 )的 Framework 做這些簡單的事。使用 Sinatra既簡單， Respond 也迅速。

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What is Rails?火車環島正夯

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What is Rails?

● It's a Web Framework

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What is Rails?

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What is Rails?

● DHH● 從 37signals 公司的專案

管理工具 Basecamp 裡面分離出 Ruby on Rails

● 2005 年獲得年度最佳 Hacker

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What is Rails?

● 正式名稱 Ruby on Rails

● 使用 MVC(Model-View-Control)● 內建 unit / integration test● 支援 Ajax, RESTfFul, ORM

● 支援最新技術 HTML5, jQuery, SASS, HAML, Coffee Script

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Design Principles

DRYDon't Repeat Yourself

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Design Principles

CoCConvention over Configuration

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Rails is so FAST!!!

JSP Rails

交貨時間4 個月，每週約 20小時

4 個晚上，每晚 5 小時

程式碼行數 3293 1164

設定檔行數 1161 113

類別數 / 方法數 62/549 55/126

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What is MVC

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What is MVC

● Model 包裝了資料與商業邏輯，例如操作資料庫● View 表示使用者介面，顯示及編輯表單● Controller 將資料送進送出 Model ，處理從外界

來的 HTTP Request ，與 Model 互動後輸出至View

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DB schema

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ActiveRecord (M)

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Rails console

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Rails console

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ActionController (C)

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ActionView (V)

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What is URL routing?

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a bloated controllerclass EventController < ApplicationController

index /events/index

show /events/show/1

new /events/new

create /events/create

show_comment /events/3/show_comment/6

mark_spamcomment /events/7/mark_spamcomment/5

add_favorite /events/2/add_favorite

invite /events/1/invite

deny_user /events/1/deny_user/13

allow_user /events/2/allow_user/27

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What is RESTful?

before after ActionController

/events/create POST /events events#create

/events/show/1 GET /events/1 events#show

/events/update/1 PUT /events/1 events#update

/events/destroy/1 DELETE /events/1 events#destroy

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Let's modify bloated controllerclass EventController < ApplicationController

index GET /events events#index

show GET /events/1 events#show

new GET /events/new events#new

create POST /events events#create

show_comment GET /events/3/comments/6 event_comments#show

mark_spamcomment PUT /events/7/comments/5/spam event_comments#spam

add_favorite POST /events/2/favorite events#favorite

invite POST /events/1/invite events#invite

deny_user PUT /events/1/users/13/deny event_users#deny

allow_user PUT /events/2/users/27/allow event_users#allow

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RESTful routing

HTTP Verb Path actionGET /photos index

GET /photos/new new

POST /photos create

GET /photos/:id show

GET /photos/:id/edit edit

PUT /photos/:id update

DELETE /photos/:id destroy

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One action, multiple formats

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One action, multiple formats

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Live DEMO...Never Live DEMO

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FAQFxxk you!?

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Why Ruby?

● Domain-specific language● Full object-oriented programming● High usability● High readability, maintenance

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Why Rails?

● The most successful Web Framework● Imitation is the greatest compliment

● CakePHP● Grails● TurboGears● catalyst

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Websites

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Java 1.6

C++ 4.2.3

Ruby 1.9.0

Python 2.5.1

PHP 5.2.3

0 100 200 300 400 500 600 700

Performance Comparison

Lines of CodeTime per iteration (microseconds)

愈小愈好

Lang

uage

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Performance is slow?

● 如果一個框架可以讓你僅變快 20% ，或許你應該繼續使用比較保險的語言，像是 Java 。但是如果你可以變快 300% 甚至更高，那麼其他的差異都變的不重要了 from Beyond Java

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Q&AQuick Asleep