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
ReactiveCocoa
Search
Robert Böhnke
May 02, 2013
Programming
19
2.7k
ReactiveCocoa
My talk for UIKonf 2013 about ReactiveCocoa and how to get rid of state
Robert Böhnke
May 02, 2013
Tweet
Share
More Decks by Robert Böhnke
See All by Robert Böhnke
Brooklyn iOS Developer Meetup February 2014
robb
8
3k
Cocoa Kucha Berlin 2013
robb
2
2.1k
ReactiveCocoa NSSpain
robb
18
2.4k
Underscore.m + Asterism
robb
4
1.2k
Super Mario Masterclass
robb
2
320
Tetris Masterclass
robb
0
520
Other Decks in Programming
See All in Programming
Boast Code Party / RubyKaigi 2025 After Event
lemonade_37
0
310
REST API設計の実践 – ベストプラクティスとその落とし穴
kentaroutakeda
2
230
Storybookの情報をMCPサーバー化する
shota_tech
3
1.6k
Agent Rules as Domain Parser
yodakeisuke
1
170
生成AI時代のフルスタック開発
kenn
9
2k
Blueskyのプラグインを作ってみた
hakkadaikon
1
140
Duke on CRaC with Jakarta EE
ivargrimstad
1
590
テスト分析入門/Test Analysis Tutorial
goyoki
8
2.5k
Feature Flag 自動お掃除のための TypeScript プログラム変換
azrsh
PRO
4
560
MLOps Japan 勉強会 #52 - 特徴量を言語を越えて一貫して管理する, 『特徴量ドリブン』な MLOps の実現への試み
taniiicom
2
350
iOSアプリ開発もLLMで自動運転する
hiragram
6
2k
Interface vs Types ~型推論が過多推論~
hirokiomote
1
200
Featured
See All Featured
Sharpening the Axe: The Primacy of Toolmaking
bcantrill
42
2.3k
What's in a price? How to price your products and services
michaelherold
245
12k
Navigating Team Friction
lara
185
15k
CSS Pre-Processors: Stylus, Less & Sass
bermonpainter
357
30k
4 Signs Your Business is Dying
shpigford
183
22k
Cheating the UX When There Is Nothing More to Optimize - PixelPioneers
stephaniewalter
280
13k
Automating Front-end Workflow
addyosmani
1370
200k
Visualizing Your Data: Incorporating Mongo into Loggly Infrastructure
mongodb
45
9.5k
[RailsConf 2023] Rails as a piece of cake
palkan
55
5.5k
Save Time (by Creating Custom Rails Generators)
garrettdimon
PRO
31
1.2k
Fireside Chat
paigeccino
37
3.5k
Producing Creativity
orderedlist
PRO
345
40k
Transcript
ReactiveCocoa OR: How I stopped worrying about state and love
FRP
✉ robb
[email protected]
tmp ceterum_censeo
Let’s talk about State
evil √
Have you tried turning it off and on again?
Have you tried turning it off and on again? Have
you tried turning it off and on again?
state
@property (readwrite, …) BOOL quacksLikeADuck; @property (readwrite, …) BOOL walksLikeADuck;
@property (readonly, …) BOOL probablyADuck;
+ (NSSet *)keyPathsForValuesAffectingProbablyADuck { return [NSSet setWithObjects:@”walksLikeADuck”, @”quacksLikeADuck”, nil]; }
- (BOOL)isProbablyADuck { return _quacksLikeADuck && _walksLikeADuck; }
ReactiveCocoa
RAC(self.probablyADuck) = [RACSignal combineLatest:@[ RACAbleWithStart(self.walksLikeADuck), RACAbleWithStart(self.quacksLikeADuck) ] reduce:^(NSNumber *walks, NSNumber
*quacks) { return @(walks.boolValue && quaks.boolValue); }];
None
[self.usernameField addTarget:self action:@selector(textFieldDidUpdate:) forControlEvents:UIControlEventEditingChanged]; [self.emailField addTarget:self action:@selector(textFieldDidUpdate:) forControlEvents:UIControlEventEditingChanged]; - (void)textFieldDidUpdate:(UITextField
*)textField { BOOL validUsername = self.usernameField.text.length > 0; BOOL validEmail = [self.emailField.text uik_isEmail]; self.signupButton.enabled = validEmail && validUsername; }
because programming
[self.usernameField addTarget:self action:@selector(textFieldDidUpdate:) forControlEvents:UIControlEventEditingChanged]; [self.emailField addTarget:self action:@selector(textFieldDidUpdate:) forControlEvents:UIControlEventEditingChanged]; - (void)textFieldDidUpdate:(UITextField
*)textField { BOOL validUsername = self.usernameField.text.length > 0; BOOL validEmail = [self.emailField.text uik_isEmail]; self.signupButton.enabled = validEmail && validUsername; }
RAC(self.signupButton.enabled) = [RACSignal combineLatest:@[ self.usernameField.rac_textSignal, self.emailField.rac_textSignal ] reduce:^(NSString *username, NSString
*email) { BOOL validUsername = username.length > 0; BOOL validEmail = [email uik_isEmail]; return @(validUsername && validEmail); }];
FRP
None
None
ReactiveCocoa
@YES @NO @YES RACSignal
<UIControlEventEditingChanged> RACSignal
{“json_string”: “ohai”} RACSignal
RACSignal - (void)sendNext:(id)value; - (void)sendCompleted; - (void)sendError:(NSError *)error;
so, what?
map, reduce, filter
Let’s talk about Asynchrony
None
Blocks are awesome
void (^cb)(id operation, id result); void (^cb)(id operation, NSError *error);
void (^cb)(id result, NSError *error); void (^cb)(NSError *error, id result);
[client logIn:^{ [client loadMeUser:^(UIKUser *user) { [client loadNewslettersForUser:user success:^(NSArray *result)
NSLog(@"Your newsletters: %@", array); } failure:^(NSError *error) { // … }]; } failure:^(NSError *error) { // … }]; } failure:^(NSError *error) { // … }];
RACSignal
- (RACSignal *)logIn; - (RACSignal *)loadMeUser; - (RACSignal *)loadNewslettersForUser:(…)user;
[[[[client logIn] sequenceNext:^{ return [client loadMeUser]; }] flattenMap:^(UIKUser *user) {
return [client loadNewslettersForUser:user]; }] subscribeNext:^(NSArray *newsletters) { NSLog(@"Your newsletters: %@", newsletters); } error:^(NSError *error) { // … }];
None
- (RACSignal *)validateEmail:(NSString *)email;
RACSignal *validEmail = [[self.emailField.rac_textSignal map:^(NSString *email) { return [[client validateEmail:email]
startWith:@NO]; }] switchToLatest]; RACSignal *validForm = [RACSignal combineLatest:@[ validUsername, validEmail ] reduce:^(NSNumber *a, NSNumber *b) { return @(a.boolValue && b.boolValue); }]; RAC(self.signupButton.enabled) = validForm;
None
where's the catch?
•conceptual overhead •debugging can get tricky (logAll is your friend)
•forces you to think
should I use it?
Probably!
state
None