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
Lighter View Controllers
Search
Chris Eidhof | @chriseidhof
February 18, 2014
Programming
5
450
Lighter View Controllers
Talk at Cocoaheads.nl
(Architecture image by Manu Cornet)
Chris Eidhof | @chriseidhof
February 18, 2014
Tweet
Share
More Decks by Chris Eidhof | @chriseidhof
See All by Chris Eidhof | @chriseidhof
Dutch FP Day 2015
chriseidhof
2
370
Tiny Networking in Swift
chriseidhof
2
19k
Functional Swift - Brooklyn
chriseidhof
3
1.2k
Functional Swift - SF
chriseidhof
6
26k
Functional Swift
chriseidhof
6
1.2k
Functional Swift
chriseidhof
1
140
Functional Programming in Swift
chriseidhof
40
19k
Lighter View Controllers
chriseidhof
4
190
Parsing with Blocks
chriseidhof
2
220
Other Decks in Programming
See All in Programming
Realtime API 入門
riofujimon
0
150
Jakarta EE meets AI
ivargrimstad
0
620
Generative AI Use Cases JP (略称:GenU)奮闘記
hideg
1
300
Quine, Polyglot, 良いコード
qnighy
4
650
Kaigi on Rails 2024 〜運営の裏側〜
krpk1900
1
240
Amazon Qを使ってIaCを触ろう!
maruto
0
410
Laravel や Symfony で手っ取り早く OpenAPI のドキュメントを作成する
azuki
2
120
受け取る人から提供する人になるということ
little_rubyist
0
250
Macとオーディオ再生 2024/11/02
yusukeito
0
370
型付き API リクエストを実現するいくつかの手法とその選択 / Typed API Request
euxn23
8
2.2k
タクシーアプリ『GO』のリアルタイムデータ分析基盤における機械学習サービスの活用
mot_techtalk
4
1.5k
最新TCAキャッチアップ
0si43
0
190
Featured
See All Featured
RailsConf & Balkan Ruby 2019: The Past, Present, and Future of Rails at GitHub
eileencodes
131
33k
Reflections from 52 weeks, 52 projects
jeffersonlam
346
20k
The Power of CSS Pseudo Elements
geoffreycrofte
73
5.3k
Docker and Python
trallard
40
3.1k
Automating Front-end Workflow
addyosmani
1366
200k
ピンチをチャンスに:未来をつくるプロダクトロードマップ #pmconf2020
aki_iinuma
109
49k
BBQ
matthewcrist
85
9.3k
Mobile First: as difficult as doing things right
swwweet
222
8.9k
Art, The Web, and Tiny UX
lynnandtonic
297
20k
How To Stay Up To Date on Web Technology
chriscoyier
788
250k
How to Think Like a Performance Engineer
csswizardry
20
1.1k
Designing Dashboards & Data Visualisations in Web Apps
destraynor
229
52k
Transcript
Lighter View Controllers Chris Eidhof CocoaHeads NL
MVC Model View Controller
MVC Model View Controller Massive View Controller
None
What's the largest file? find . -name "*.m" -exec wc
-l "{}" \; | sort -n
Steps Project: A complete OS in < 20K lines
View Controllers are the least reusable part
A view controller intermediates between model and view
Model logic
View logic
View layout
Web Service
Too much already?
Delegates
IBActions ?
Pragma marks ??
None
Child View Controllers
Table View Controllers ☆ Editing Mode ☆ Keyboard notifications ☆
Flashing scroll indicators ☆ Clearing Selection ☆ Pull to Refresh
None
None
View Controller Transitions
None
Pulling out protocols
For example: UITableViewDataSource
Creating a separate data source object @interface FetchedResultsControllerDataSource : NSObject
<UITableViewDataSource, NSFetchedResultsControllerDelegate>
Creating a separate data source object - (NSInteger)numberOfSectionsInTableView:(UITableView*)t { return
self.fetchedResultsController.sections.count; }
Creating a separate data source object - (NSInteger)tableView:(UITableView*)tableView numberOfRowsInSection:(NSInteger)sectionIndex {
id<NSFetchedResultsSectionInfo> section; section = self.frc.sections[sectionIndex]; return section.numberOfObjects; }
Creating a separate data source object Working with the delegate
- (UITableViewCell*)tableView:(UITableView*)tv cellForRowAtIndexPath:(NSIndexPath*)ip { id object = [self objectAtIndexPath:indexPath]; id cell = [tv dequeueReusableCellWithIdentifier:ruI forIndexPath:ip]; [self.delegate configureCell:cell withObject:object]; return cell; }
Advantages of a separate data source ☆ Lighter view controller
☆ Testable ☆ Reusable And you can do this for other protocols, too...
A separate data source ☆ NSArrayDataSource ☆ NSFRCollectionViewController ☆ ...
Categories
Configuring a cell - (UITableViewCell*)tableView:(UITableView*)tv cellForRowAtIndexPath:(NSIndexPath*)ip { PhotoCell *cell =
[tableView dequeueReusableCellWithIdentifier:@"PhotoCell"]; Photo *photo = [self itemAtIndexPath:indexPath]; cell.photoTitleLabel.text = photo.name; NSString* date = [self.dateFormatter stringFromDate:photo.creationDate]; cell.photoDateLabel.text = date; }
Configuring a cell Pulling out the reusable part @implementation PhotoCell
(ConfigureForPhoto) - (void)configureForPhoto:(Photo *)photo { self.photoTitleLabel.text = photo.name; NSString* date = [self.dateFormatter stringFromDate:photo.creationDate]; self.photoDateLabel.text = date; } @end
Configuring a cell The refactored delegate method - (UITableViewCell *)tableView:(UITableView
*)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { PhotoCell *cell = [tableView dequeueReusableCellWithIdentifier:PhotoCellIdentifier]; [cell configureForPhoto:[self itemAtIndexPath:indexPath]]; return cell; }
Using Interface Builder
None
Intentions
Intentions View Controllers may only contain code that effects view
changes in response to data changes. Source: http://bendyworks.com/geekville/articles/ 2014/2/single-responsibility-principle-ios
Intentions The IBAction macro must not be used in a
View Controller
Intentions The @interface block in a View Controller's header file
must be blank.
Intentions A View Controller may not implement any extra *Delegate
or *DataSource protocols except for observing Model changes.
Intentions A View Controller may only do work in viewDidLoad
(or awakeFromNib), viewDidAppear, viewDidDisappear, and in response to an observed change in the model layer.
None
Testing
Testing View controllers are notoriously hard to test → Make
them light.
Commercial Break
None
None
Questions? @chriseidhof