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
90
Other Decks in Programming
See All in Programming
iOS 26にアップデートすると実機でのHot Reloadができない?
umigishiaoi
0
130
なぜ適用するか、移行して理解するClean Architecture 〜構造を超えて設計を継承する〜 / Why Apply, Migrate and Understand Clean Architecture - Inherit Design Beyond Structure
seike460
PRO
3
780
MDN Web Docs に日本語翻訳でコントリビュートしたくなる
ohmori_yusuke
1
130
The Evolution of Enterprise Java with Jakarta EE 11 and Beyond
ivargrimstad
0
140
Python型ヒント完全ガイド 初心者でも分かる、現代的で実践的な使い方
mickey_kubo
1
150
なぜ「共通化」を考え、失敗を繰り返すのか
rinchoku
1
660
すべてのコンテキストを、 ユーザー価値に変える
applism118
4
1.4k
おやつのお供はお決まりですか?@WWDC25 Recap -Japan-\(region).swift
shingangan
0
140
PHPで始める振る舞い駆動開発(Behaviour-Driven Development)
ohmori_yusuke
2
410
テスト駆動Kaggle
isax1015
1
480
ご注文の差分はこちらですか? 〜 AWS CDK のいろいろな差分検出と安全なデプロイ
konokenj
3
370
ふつうの技術スタックでアート作品を作ってみる
akira888
1
1.1k
Featured
See All Featured
Easily Structure & Communicate Ideas using Wireframe
afnizarnur
194
16k
Typedesign – Prime Four
hannesfritz
42
2.7k
Code Review Best Practice
trishagee
69
19k
Creating an realtime collaboration tool: Agile Flush - .NET Oxford
marcduiker
30
2.1k
Writing Fast Ruby
sferik
628
62k
Making Projects Easy
brettharned
116
6.3k
YesSQL, Process and Tooling at Scale
rocio
173
14k
10 Git Anti Patterns You Should be Aware of
lemiorhan
PRO
656
60k
Side Projects
sachag
455
42k
Chrome DevTools: State of the Union 2024 - Debugging React & Beyond
addyosmani
7
740
The Web Performance Landscape in 2024 [PerfNow 2024]
tammyeverts
8
700
Thoughts on Productivity
jonyablonski
69
4.7k
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