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
Connect.Tech 2017: Functional Web with Elm
Search
Jeremy Fairbank
September 20, 2017
Programming
0
180
Connect.Tech 2017: Functional Web with Elm
Jeremy Fairbank
September 20, 2017
Tweet
Share
More Decks by Jeremy Fairbank
See All by Jeremy Fairbank
Connect.Tech 2020: Advanced Cypress Testing
jfairbank
1
200
CodeMash 2020: Solving the Boolean Identity Crisis
jfairbank
1
150
CodeMash 2020: Practical Functional Programming
jfairbank
1
320
Connect.Tech 2019: Practical Functional Programming
jfairbank
0
350
Connect.Tech 2019: Solving the Boolean Identity Crisis
jfairbank
0
180
Lambda Squared 2019: Solving the Boolean Identity Crisis
jfairbank
0
120
All Things Open 2018: Practical Functional Programming
jfairbank
2
260
Connect.Tech 2018: Effective React Testing
jfairbank
1
160
Fluent Conf 2018: Building web apps with Elm Tutorial
jfairbank
2
850
Other Decks in Programming
See All in Programming
Blazing Fast UI Development with Compose Hot Reload (droidcon New York 2025)
zsmb
1
190
Railsアプリケーションと パフォーマンスチューニング ー 秒間5万リクエストの モバイルオーダーシステムを支える事例 ー Rubyセミナー 大阪
falcon8823
4
930
Google Agent Development Kit でLINE Botを作ってみた
ymd65536
2
160
地方に住むエンジニアの残酷な現実とキャリア論
ichimichi
5
1.3k
プロダクト志向ってなんなんだろうね
righttouch
PRO
0
160
今ならAmazon ECSのサービス間通信をどう選ぶか / Selection of ECS Interservice Communication 2025
tkikuc
19
3.5k
PostgreSQLのRow Level SecurityをPHPのORMで扱う Eloquent vs Doctrine #phpcon #track2
77web
2
300
C++20 射影変換
faithandbrave
0
530
Cursor AI Agentと伴走する アプリケーションの高速リプレイス
daisuketakeda
1
130
Systèmes distribués, pour le meilleur et pour le pire - BreizhCamp 2025 - Conférence
slecache
0
100
DroidKnights 2025 - 다양한 스크롤 뷰에서의 영상 재생
gaeun5744
3
320
コードの90%をAIが書く世界で何が待っているのか / What awaits us in a world where 90% of the code is written by AI
rkaga
46
30k
Featured
See All Featured
The Invisible Side of Design
smashingmag
299
51k
The Power of CSS Pseudo Elements
geoffreycrofte
77
5.8k
A Tale of Four Properties
chriscoyier
160
23k
Practical Orchestrator
shlominoach
188
11k
Java REST API Framework Comparison - PWX 2021
mraible
31
8.6k
How STYLIGHT went responsive
nonsquared
100
5.6k
Optimising Largest Contentful Paint
csswizardry
37
3.3k
Performance Is Good for Brains [We Love Speed 2024]
tammyeverts
10
930
Into the Great Unknown - MozCon
thekraken
39
1.9k
GraphQLの誤解/rethinking-graphql
sonatard
71
11k
Building Flexible Design Systems
yeseniaperezcruz
328
39k
No one is an island. Learnings from fostering a developers community.
thoeni
21
3.3k
Transcript
Jeremy Fairbank @elpapapollo / jfairbank Functional Web with Elm Visit
README for demo and exercise URLs: https://github.com/jfairbank/elm-workshop
Software is broken. We are here to fix it. Say
[email protected]
Functional and statically typed programming language for frontend development elm
Web and UI Focused
Compiles to JavaScript
No runtime exceptions in practice.
The 2nd argument to function `add` is causing a mismatch.
7| add 2 "3" ^^^ Function `add` is expecting the 2nd argument to be: Int But it is: String Compile time static type checks
Functional
Pure Data in Data out
Pure No side effects
Pure Predictable and Testable!
Immutable Data • Safety and consistency • Explicit flow of
data • No subtle mutation bugs
No undefined is not a function
Fast
One framework. No fatigue. Update View Model Messages
✓ Easier to write code ✓ Easier to write tests
✓ Easier to refactor
Content • Functions and expressions • Lists, records, and immutability
• Static types and type aliases • Union types and pattern matching • Building Apps with the Elm Architecture
Format • Demos via ellie-app.com • Exercises via ellie-app.com •
Q&A
README for demo and exercise URLs: github.com/jfairbank/elm-workshop
Update View Model Messages The Elm Architecture
Application State Model
Model Virtual DOM View UI as a Function
elm Virtual DOM Todo List Learn Elm Build awesome Elm
apps Learn functional programming <html /> Model: Todo List
× Todo List Learn Elm Build awesome Elm apps Learn
functional programming User deletes first todo item <html /> Model: New Todo List
Todo List Learn Elm Build awesome Elm apps Learn functional
programming View Model: New Todo List Elm notices missing todo item in virtual DOM list, so it just removes the corresponding <li> instead of fully rendering. elm Virtual DOM ×<html />
Messages Standardized application events
elm app model
elm app model Events Text Input Mouse Click Associate message
with event
elm app model Events Text Input Mouse Click When event
triggers (i.e. user clicks), deliver message
Update Model New Model Respond to messages and create new
state
model Update View
model Update View
model Update View VDOM
model Update View VDOM
model Update View Select red color
model Update View Select red color
model Update View Select red color
model Update View
model Update View
model Update View
model Update View VDOM
model Update View VDOM
Demo and Exercise
Resources • elm-lang.org • elm-lang.org/examples • guide.elm-lang.org • www.elm-tutorial.org •
builtwithelm.co • Slack • elmlang.herokuapp.com
Thanks! Jeremy Fairbank @elpapapollo / jfairbank Slides: bit.ly/elm-connect