Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Practically Immutable
Search
sporto
March 28, 2015
Technology
0
190
Practically Immutable
Immutable data in practice in JavaScript
sporto
March 28, 2015
Tweet
Share
More Decks by sporto
See All by sporto
React inside Elm
sporto
2
180
Elm
sporto
1
250
Redux: Flux Reduced
sporto
1
330
Webpack and React
sporto
4
380
Rails with Webpack
sporto
1
220
Lesson learnt building Single Page Application
sporto
0
120
Grunt
sporto
1
180
Safe Testing in Ruby
sporto
1
130
Go - A great language for building web applications
sporto
1
340
Other Decks in Technology
See All in Technology
開発者を支える Internal Developer Portal のイマとコレカラ / To-day and To-morrow of Internal Developer Portals: Supporting Developers
aoto
PRO
1
290
DDD集約とサービスコンテキスト境界との関係性
pandayumi
2
260
「魔法少女まどか☆マギカ Magia Exedra」のグローバル展開を支える、開発チームと翻訳チームの「意識しない協創」を実現するローカライズシステム
gree_tech
PRO
0
540
Agile PBL at New Grads Trainings
kawaguti
PRO
1
270
『FailNet~やらかし共有SNS~』エレベーターピッチ
yokomachi
1
200
【5分でわかる】セーフィー エンジニア向け会社紹介
safie_recruit
0
30k
5年目から始める Vue3 サイト改善 #frontendo
tacck
PRO
3
190
まだ間に合う! StrandsとBedrock AgentCoreでAIエージェント構築に入門しよう
minorun365
PRO
11
910
250905 大吉祥寺.pm 2025 前夜祭 「プログラミングに出会って20年、『今』が1番楽しい」
msykd
PRO
1
450
Codeful Serverless / 一人運用でもやり抜く力
_kensh
4
120
バッチ処理で悩むバックエンドエンジニアに捧げるAWS Glue入門
diggymo
3
120
Webブラウザ向け動画配信プレイヤーの 大規模リプレイスから得た知見と学び
yud0uhu
0
210
Featured
See All Featured
Imperfection Machines: The Place of Print at Facebook
scottboms
268
13k
Building Applications with DynamoDB
mza
96
6.6k
Building Better People: How to give real-time feedback that sticks.
wjessup
368
19k
ReactJS: Keep Simple. Everything can be a component!
pedronauck
667
120k
Six Lessons from altMBA
skipperchong
28
4k
YesSQL, Process and Tooling at Scale
rocio
173
14k
A Tale of Four Properties
chriscoyier
160
23k
Fight the Zombie Pattern Library - RWD Summit 2016
marcelosomers
234
17k
Improving Core Web Vitals using Speculation Rules API
sergeychernyshev
18
1.1k
GitHub's CSS Performance
jonrohan
1032
460k
For a Future-Friendly Web
brad_frost
180
9.9k
Templates, Plugins, & Blocks: Oh My! Creating the theme that thinks of everything
marktimemedia
31
2.5k
Transcript
practically immutable ! Immutable data in JS @sebasporto
I build CRUD apps, mostly
What? • Something that cannot change • Once created stays
the same
var array1 = [1, 2].immutable var array2 = array1.push(3) !
array1 //=> [1, 2] array2 //=> [1, 2, 3]
WHY?
# 1 no side effects
var orders = [1, 2]; processOrders(orders); what is orders after
this?
Predictability Store Comp Comp Data Data wants to sort data
wants to transform data doesn't want its data to be modified externally
Enforces uni directional data flow React + Flux Store Comp
Action
# 2 Easier workflows
Undo add(item) { history.push(items) items = items.push(item) } undo() {
items = history.pop() }
Dirty objects Get record from store Clone record Edit record
Save Replace original Yes Discard No
Dirty objects Get record from store Edit record Save Replace
original Yes Discard No
HOW?
clojurescript immutable data for free but this talk is about
plain JS
• In JS strings and numbers are immutable (not the
case in every language) • Arrays, objects are not - so we need help here • JS and immutable data => opposing forces
immutable.js • Great for simple collections • [1, 2, ...]
['a', 'b' ...] • Caveats for collections with objects https://github.com/facebook/immutable-js
Immutable.js var record = {label: 'Sam'}; var list = Immutable.List([record]);
! console.log(list.get(0).label) // => 'Sam' http://jsbin.com/dilupu/1/embed?js,console record.label = 'Biff' ! console.log(list.get(0).label) // => 'Biff' Opps!
immutable.js To be fair: Immutable.js can do the right thing
if you learn it really well Immutable.js != Just works™
Seamless immutable • Fixes Immutable.js issues with deep objects https://github.com/rtfeldman/seamless-immutable
var record = {label: 'Sam'}; var list = Immutable([record]); !
console.log(list[0].label) // => 'Sam' ! record.label = 'Biff' ! console.log(list[0].label) // => 'Sam' http://jsbin.com/fayupu/1/edit?js,console Seamless immutable
imm https://github.com/sporto/imm • Build on top of seamless-immutable • Nice
CRUD API
imm list = list.add(record) list = list.replace(record) list = list.remove(id)
! record = list.get(id)
in Conclusion
Immutable data can make your application more robust
but play a lot with your chosen lib, understand
the caveats
Thanks