Upgrade to Pro — share decks privately, control downloads, hide ads and more …

State Pattern From GoF

Sponsored · Ship Features Fearlessly Turn features on and off without deploys. Used by thousands of Ruby developers. →
Avatar for Chris Bushell Chris Bushell
July 07, 2010
Programming
72
1

State Pattern From GoF

Prepared for the Melbourne Patterns Group

Avatar for Chris Bushell

Chris Bushell

July 07, 2010

More Decks by Chris Bushell

See All by Chris Bushell
Test Automation for Packaged Systems: Yes You Can!
Avatar for Chris Bushell cbushell
0
65
Introduction to Pair Programming
Avatar for Chris Bushell cbushell
1
130
An Introduction to BDD
Avatar for Chris Bushell cbushell
5
170
An Introduction to HTTP
Avatar for Chris Bushell cbushell
2
130
Agile Test Automation
Avatar for Chris Bushell cbushell
2
180
Working Effectively With Legacy Code
Avatar for Chris Bushell cbushell
4
260
Jasmine, BDD for JavaScript
Avatar for Chris Bushell cbushell
1
130
Branches Are For Trees. How to Develop Software Without Them
Avatar for Chris Bushell cbushell
1
120
Continuous Integration, fast builds and Flot
Avatar for Chris Bushell cbushell
2
79

Other Decks in Programming

See All in Programming
LM Linkで(非力な！)ノートPCでローカルLLM
Avatar for 瀬尾佳隆 seosoft
0
480
How Swift's Type System Guides AI Agents
Avatar for Yuta Koshizawa koher
0
250
The Monolith Strikes Back: Why AI Agents ❤️ Rails Monoliths
Avatar for Rodrigo Serradura serradura
0
320
Coding as Prompting Since 2025
Avatar for Jimmy Moon ragingwind
0
830
「速くなった気がする」をデータで疑う
Avatar for Leaf senleaf24
0
170
iOS機能開発のAI環境と起きた変化
Avatar for Ryu-nakayama ryunakayama
0
180
Mastering Event Sourcing: Your Parents Holidayed in Yugoslavia
Avatar for Marek Matulka super_marek
0
150
Feature Toggle は捨てやすく使おう
Avatar for gennei gennei
0
590
Getting more out of Maven
Avatar for Marit van Dijk mlvandijk
0
110
Server-Side Kotlin LT大会 vol.18 [Kotlin-lspの最新情報と Neovimのlsp設定例]
Avatar for yasunori yasunori0418
1
130
Claude Codeをカスタムして自分だけのClaude Codeを作ろう
Avatar for Terisuke terisuke
0
120
Going Multiplatform with Your Android App (Android Makers 2026)
Avatar for Márton Braun zsmb
2
400

Featured

See All Featured
Money Talks: Using Revenue to Get Sh*t Done
Avatar for Nikki Halliwell nikkihalliwell
0
200
Ecommerce SEO: The Keys for Success Now & Beyond - #SERPConf2024
Avatar for Aleyda Solis aleyda
1
1.9k
Building the Perfect Custom Keyboard
Avatar for Naoto Takai takai
2
730
jQuery: Nuts, Bolts and Bling
Avatar for Doug Neiner dougneiner
66
8.4k
brightonSEO & MeasureFest 2025 - Christian Goodrich - Winning strategies for Black Friday CRO & PPC
Avatar for Christian Goodrich cargoodrich
3
680
Fireside Chat
Avatar for paigeccino paigeccino
42
3.9k
ラッコキーワード サービス紹介資料
Avatar for ラッコ株式会社 rakko
1
3M
A Tale of Four Properties
Avatar for Chris Coyier chriscoyier
163
24k
Fashionably flexible responsive web design (full day workshop)
Avatar for Andy Clarke malarkey
408
66k
Amusing Abliteration
Avatar for ianozsvald ianozsvald
1
150
The MySQL Ecosystem @ GitHub 2015
Avatar for Sam Lambert samlambert
251
13k
Templates, Plugins, & Blocks: Oh My! Creating the theme that thinks of everything
Avatar for Michelle Schulp Hunt marktimemedia
31
2.8k

Transcript

  1. State  Pa'ern  From  GoF   Chris  Bushell  7th  July  2010

       

  2. Mo<va<on   “Allow  an  object  to  alter  its  behavior  when

     its   internal  state  changes”  

  3. Code  

  4. Applicability   •  Behavior  depends  on  state   •  Opera<ons

     have  large  condi<onal  statements   which  depend  on  state  

  5. Par<cipants  

  6. Collabora<ons   •  Context  and  Concrete  State   •  Context

     is  primary  interface  for  clients  

  7. Consequences   •  Localizes  state  specific  behavior.  Avoids  code  

    duplica<on   •  State  changes  are  well  defined,  atomic   opera<ons   •  State  objects  can  be  shared  

  8. Implementa<on   •  Context  or  Concrete  State  defines  transi<ons?  

    •  Table  based  approach  to  defining  transi<ons   •  Singleton,  Flyweight