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
Data Source Combinators
Search
Rob Brown
April 02, 2015
Programming
2
70
Data Source Combinators
Eliminating the boilerplate from UITableView and UICollectionView.
Rob Brown
April 02, 2015
Tweet
Share
More Decks by Rob Brown
See All by Rob Brown
High-level Concurrency
robbrown
1
60
Elixir
robbrown
1
220
MVVM
robbrown
3
250
Reactive Cocoa
robbrown
2
140
UIKit Dynamics
robbrown
0
69
iOS State Preservation and Restoration
robbrown
5
740
Anti-Patterns
robbrown
3
120
Core Animation: Beyond the Basics
robbrown
1
85
Pragmatic Blocks
robbrown
3
89
Other Decks in Programming
See All in Programming
童醫院敏捷轉型的實踐經驗
cclai999
0
180
アンドパッドの Go 勉強会「 gopher 会」とその内容の紹介
andpad
0
260
Systèmes distribués, pour le meilleur et pour le pire - BreizhCamp 2025 - Conférence
slecache
0
100
AIコーディング道場勉強会#2 君(エンジニア)たちはどう生きるか
misakiotb
1
240
来たるべき 8.0 に備えて React 19 新機能と React Router 固有機能の取捨選択とすり合わせを考える
oukayuka
2
840
関数型まつり2025登壇資料「関数プログラミングと再帰」
taisontsukada
2
850
LINEヤフー データグループ紹介
lycorp_recruit_jp
0
810
プロダクト志向なエンジニアがもう一歩先の価値を目指すために意識したこと
nealle
0
110
XP, Testing and ninja testing
m_seki
3
180
Create a website using Spatial Web
akkeylab
0
300
イベントストーミング図からコードへの変換手順 / Procedure for Converting Event Storming Diagrams to Code
nrslib
1
320
PHPで始める振る舞い駆動開発(Behaviour-Driven Development)
ohmori_yusuke
2
180
Featured
See All Featured
The Myth of the Modular Monolith - Day 2 Keynote - Rails World 2024
eileencodes
26
2.9k
ReactJS: Keep Simple. Everything can be a component!
pedronauck
667
120k
"I'm Feeling Lucky" - Building Great Search Experiences for Today's Users (#IAC19)
danielanewman
228
22k
[RailsConf 2023 Opening Keynote] The Magic of Rails
eileencodes
29
9.5k
Build The Right Thing And Hit Your Dates
maggiecrowley
36
2.8k
Bootstrapping a Software Product
garrettdimon
PRO
307
110k
Improving Core Web Vitals using Speculation Rules API
sergeychernyshev
16
940
Writing Fast Ruby
sferik
628
61k
Connecting the Dots Between Site Speed, User Experience & Your Business [WebExpo 2025]
tammyeverts
5
210
XXLCSS - How to scale CSS and keep your sanity
sugarenia
248
1.3M
Practical Tips for Bootstrapping Information Extraction Pipelines
honnibal
PRO
20
1.3k
Understanding Cognitive Biases in Performance Measurement
bluesmoon
29
1.8k
Transcript
Data$Source$Combinators ©"Robert"Brown"March"2015"@robby_brown
Table&Views you're'doing'them'wrong ©"Robert"Brown"March"2015"@robby_brown
Overview 1. The&Hard&Way 2. Code&Architecture&Theory 3. The&Be7er&Way ©"Robert"Brown"March"2015"@robby_brown
Demo ©"Robert"Brown"March"2015"@robby_brown
The$Hard$Way ©"Robert"Brown"March"2015"@robby_brown
Cell$Crea'on class CandyTableViewController : UITableViewController { override func tableView(tableView: UITableView,
numberOfRowsInSection section: Int) -> Int { return self.candies.count } override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell { let cell = self.tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as UITableViewCell let candy = self.candies[indexPath.row] cell.textLabel!.text = candy.name cell.accessoryType = UITableViewCellAccessoryType.DisclosureIndicator return cell } } From:&raywenderlich.com ©"Robert"Brown"March"2015"@robby_brown
Cell$Crea'on What's'wrong'with'this? • Duplicate+boilerplate • View+controllers+handle+interac5on,+not+data+ sources • Cells+are+o8en+shared+between+table+views •
Cells+should+handle+their+own+layout ©"Robert"Brown"March"2015"@robby_brown
Cell$Crea'on Why$do$we$see$this$so$o,en? • It's&"standard"&prac.ce • That's&how&I've&always&done&it • My&favorite&tutorial&does&it • Apple&does&it
©"Robert"Brown"March"2015"@robby_brown
Cell$Crea'on Why$do$we$see$this$so$o,en? • It's&really&convenient&for&tutorials&to&be&simple ©"Robert"Brown"March"2015"@robby_brown
Code%Architecture%Theory ©"Robert"Brown"March"2015"@robby_brown
Data$Sources Problems: • Massive(View(Controller • Duplicate(boilerplate ©"Robert"Brown"March"2015"@robby_brown
Data$Sources Solu%on: • Single(responsibility0principle • Combinators • Chain(of(responsibility ©"Robert"Brown"March"2015"@robby_brown
A"class"should"have"only"one" reason"to"change. —"Single)responsibility"principle ©"Robert"Brown"March"2015"@robby_brown
A"class"should"have"only"one" reason"to"change. —"Single)responsibility"principle ©"Robert"Brown"March"2015"@robby_brown
Every&class&should&have& responsibility&over&a&single& part&of&the&func6onality...,& and&that&responsibility&should& be&en6rely&encapsulated&by& the&class.1 —"Single)responsibility"principle 1"Wikipedia ©"Robert"Brown"March"2015"@robby_brown
Combinators • Technique*from*func/onal*programming • Usually*seen*with*parsers • Generally*represent*a*single,*simple*feature • Focus*on*composi/on •
Like*higher>order*func/ons*applied*to*features ©"Robert"Brown"March"2015"@robby_brown
Chain&of&Responsibility • Like&a&chain&of&delegates • A&3>&B&3>&C&3>&D&... • If&A&can't&handle&something,&then&try&B&... • Used&to&create&a&sequence&of&combinators ©"Robert"Brown"March"2015"@robby_brown
The$Be&er$Way ©"Robert"Brown"March"2015"@robby_brown
Cell$Crea'on View%Controller override func viewDidLoad() { super.viewDidLoad() let objects =
[] // Get objects here tableView.dataSource = BaseDataSource(objects) { (view, indexPath, object) -> Any in return MyCell.cell(view as! UITableView, name: object as! String) } } ©"Robert"Brown"March"2015"@robby_brown
Cell$Crea'on View%Controller override func viewDidLoad() { super.viewDidLoad() let objects =
[] // Get objects here let base = BaseDataSource(objects) { (view, indexPath, object) -> Any in return MyCell.cell(view as! UITableView, name: object as! String) } self.dataSource = ReorderableDataSource(base) } ©"Robert"Brown"March"2015"@robby_brown
Cell$Crea'on Cell class MyCell: SmartTableViewCell { @IBOutlet weak var titleLabel:
UILabel! class func cell(tableView: UITableView, name: String) -> Self { let cell = self.cell(tableView) cell.titleLabel.text = name return cell } } ©"Robert"Brown"March"2015"@robby_brown
Cell$Crea'on Why$is$this$be*er? • Fewer&lines&of&code • Boilerplate&removed • Behavior&can&be&changed&with&the&data&source(s) • The&data&source&can&work&with&table&and&collec=on&
views • Easier&to&build&combinators ©"Robert"Brown"March"2015"@robby_brown
Dynamic(Behaviors • Array • Mul)*dimensional2array • Filtering • Reordering •
Edi)ng • Index2)tles ©"Robert"Brown"March"2015"@robby_brown
Considera*ons • The%order%of%combinators%applied%ma4ers%for% performance • Ex:%Create%index%9tles%before%filtering • Some9mes%a%combinator%needs%to%implement%more% than%one%feature%for%performance ©"Robert"Brown"March"2015"@robby_brown
Example(Combinators • BaseDataSource:#Provides#minimum# func1onality • ChainableDataSource:#Allows#data#source# sequences • FilterableDataSource:#Allows#filtering#(ex.# search#bar)
• ReorderableDataSource:#Allows#reordering • IndexableDataSource:#Shows#index#1tles ©"Robert"Brown"March"2015"@robby_brown
Demo ©"Robert"Brown"March"2015"@robby_brown
Summary 1. The&Hard&Way 2. Code&Architecture&Theory 3. The&Be7er&Way ©"Robert"Brown"March"2015"@robby_brown
Ques%ons? ©"Robert"Brown"March"2015"@robby_brown
Resources(to(Learn(More • Source(Code • Combinator • Func2onal(Programming(in(Swi7 • Func2onal(Snippets ©"Robert"Brown"March"2015"@robby_brown
Resources(to(Learn(More • Separa'on*of*Concerns • Cohesion • Orthogonality ©"Robert"Brown"March"2015"@robby_brown