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 NSSpain
Search
Robert Böhnke
September 18, 2013
Programming
18
2.4k
ReactiveCocoa NSSpain
My talk for NSSpain 2013 on ReactiveCocoa
Robert Böhnke
September 18, 2013
Tweet
Share
More Decks by Robert Böhnke
See All by Robert Böhnke
Brooklyn iOS Developer Meetup February 2014
robb
8
3.1k
Cocoa Kucha Berlin 2013
robb
2
2.1k
Underscore.m + Asterism
robb
4
1.2k
ReactiveCocoa
robb
19
2.7k
Super Mario Masterclass
robb
2
320
Tetris Masterclass
robb
0
530
Other Decks in Programming
See All in Programming
Claude Code と OpenAI o3 で メタデータ情報を作る
laket
0
130
DockerからECSへ 〜 AWSの海に出る前に知っておきたいこと 〜
ota1022
5
1.8k
Kiroの仕様駆動開発から見えてきたAIコーディングとの正しい付き合い方
clshinji
1
120
Portapad紹介プレゼンテーション
gotoumakakeru
1
130
Honoアップデート 2025年夏
yusukebe
1
830
The State of Fluid (2025)
s2b
0
190
物語を動かす行動"量" #エンジニアニメ
konifar
14
5.4k
Terraform やるなら公式スタイルガイドを読もう 〜重要項目 10選〜
hiyanger
13
3.2k
Nuances on Kubernetes - RubyConf Taiwan 2025
envek
0
180
画像コンペでのベースラインモデルの育て方
tattaka
3
1.8k
kiroでゲームを作ってみた
iriikeita
0
180
Dart 参戦!!静的型付き言語界の隠れた実力者
kno3a87
0
200
Featured
See All Featured
Let's Do A Bunch of Simple Stuff to Make Websites Faster
chriscoyier
507
140k
GitHub's CSS Performance
jonrohan
1031
460k
Speed Design
sergeychernyshev
32
1.1k
10 Git Anti Patterns You Should be Aware of
lemiorhan
PRO
656
61k
Faster Mobile Websites
deanohume
309
31k
How to Ace a Technical Interview
jacobian
279
23k
Thoughts on Productivity
jonyablonski
69
4.8k
Documentation Writing (for coders)
carmenintech
73
5k
The Illustrated Children's Guide to Kubernetes
chrisshort
48
50k
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
126
53k
Into the Great Unknown - MozCon
thekraken
40
2k
The Cost Of JavaScript in 2023
addyosmani
53
8.8k
Transcript
robb
[email protected]
ceterum_censeo
speakerdeck.com/robb/ reactivecocoa-nsspain
Let's talk about ReactiveCocoa
Let's talk about ReactiveCocoa 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?
Start Okay Fail
Start Okay Fail power-cycle power-cycle
state
state
duh! " " you say
e.g.
@property (readwrite) BOOL walks; @property (readwrite) BOOL quaks; @property (readonly)
BOOL duck;
duck = walks ∧ quaks
- (void)setWalks:(BOOL)walks { _walks = walks; self.duck = walks &&
self.quacks; }
- (void)setWalks:(BOOL)walks { _walks = walks; self.duck = walks &&
self.quacks; } - (void)setQuacks:(BOOL)quacks { _quacks = quacks; self.duck = quacks && self.walks; }
- (void)setWalks:(BOOL)walks { _walks = walks; self.duck = walks &&
self.quacks; } - (void)setQuacks:(BOOL)quacks { _quacks = quacks; self.duck = quacks && self.walks; }
- (BOOL)duck { return self.walks && self.quacks; }
- (NSSet *)keyPathsForValuesAffectingDuck { return [NSSet setWithArray:@[ @"walks", @"quacks" ]];
} - (BOOL)duck { return self.walks && self.quacks; }
- (BOOL)duck { return self.walks && self.quacks; } // duck
= walks ∧ quaks
ReactiveCocoa
Functional Reactive Programming
Signals instead of variables
Pipes, not boxes
wtf? " " you may be thinking
e.g.
RAC(self, duck) = [RACSignal combineLatest:@[ RACObserve(self, walks), RACObserve(self, quacks) ]
reduce:^(NSNumber *walks, NSNumber *quacks) { return @(walks.boolValue && quacks.boolValue); }]:
RAC(self, duck) = [RACSignal combineLatest:@[ RACObserve(self, walks), RACObserve(self, quacks) ]
reduce:^(NSNumber *walks, NSNumber *quacks) { return @(walks.boolValue && quacks.boolValue); }]:
RAC(self, duck) = [RACSignal combineLatest:@[ RACObserve(self, walks), RACObserve(self, quacks) ]
reduce:^(NSNumber *walks, NSNumber *quacks) { return @(walks.boolValue && quacks.boolValue); }]:
RAC(self, duck) = [RACSignal combineLatest:@[ RACObserve(self, walks), RACObserve(self, quacks) ]
reduce:^(NSNumber *walks, NSNumber *quacks) { return @(walks.boolValue && quacks.boolValue); }]:
RAC(self, duck) = [RACSignal combineLatest:@[ RACObserve(self, walks), RACObserve(self, quacks) ]
reduce:^(NSNumber *walks, NSNumber *quacks) { return @(walks.boolValue && quacks.boolValue); }]:
// and it even does KVO! RAC(self, duck) = [RACSignal
combineLatest:@[ RACObserve(self, walks), RACObserve(self, quacks) ] reduce:^(NSNumber *walks, NSNumber *quacks) { return @(walks.boolValue && quacks.boolValue); }]:
& walks talks duck
& walks talks duck
& walks talks duck
& walks talks duck
& walks talks duck
RACSignal
-(RACDisposable * )subscribe:(id<RACSubscriber> )obj; RACSignal
<RACSubscriber>
- (void)sendNext:(id)value; <RACSubscriber>
- (void)sendNext:(id)value; - (void)sendCompleted; <RACSubscriber>
- (void)sendNext:(id)value; - (void)sendCompleted; - (void)sendError:(NSError *)error; <RACSubscriber>
so what?
Powerful toolset
map
filter
fold
write declarative code
e.g.
Your name Your email address Sign Up Newsletter
Newsletter Your name Your email address Sign Up
Newsletter Your email address Sign Up robb
Newsletter Sign Up robb robb
Newsletter Sign Up robb @robb.is Sign Up robb
Your name Your email address Sign Up validate that looks
familiar! Newsletter
- (void)viewDidLoad { [super viewDidLoad]; [self.username addTarget:self action:@selector(textFieldTextDidChange:) forControlEvents:UIControlEventAllEditingEvents]; [self.email
addTarget:self action:@selector(textFieldTextDidChange:) forControlEvents:UIControlEventAllEditingEvents]; } help!
- (void)textFieldTextDidChange:(UITextField *)field { BOOL validUsername = self.username.text.length > 0;
NSRange at = [self.email.text rangeOfString:@"@"]; BOOL validEmail = at.location != NSNotFound; self.signupButton.enabled = validUsername && validEmail; }
- (void)textFieldTextDidChange:(UITextField *)field { BOOL validUsername = self.username.text.length > 0;
NSRange at = [self.email.text rangeOfString:@"@"]; BOOL validEmail = at.location != NSNotFound; self.signupButton.enabled = validUsername && validEmail; }
ReactiveCocoa
RAC(self.signUpButton, enabled) = [RACSignal combineLatest:@[ self.name.rac_textSignal self.email.rac_textSignal ] reduce:^(NSString *name,
NSString *email) { NSRange at = [email rangeOfString:@"@"]; return @(at.location != NSNotFound && name.length > 0); }]:
RAC(self.signUpButton, enabled) = [RACSignal combineLatest:@[ self.name.rac_textSignal self.email.rac_textSignal ] reduce:^(NSString *name,
NSString *email) { NSRange at = [email rangeOfString:@"@"]; return @(at.location != NSNotFound && name.length > 0); }]:
RAC(self.signUpButton, enabled) = [RACSignal combineLatest:@[ self.name.rac_textSignal self.email.rac_textSignal ] reduce:^(NSString *name,
NSString *email) { NSRange at = [email rangeOfString:@"@"]; return @(at.location != NSNotFound && name.length > 0); }]:
RAC(self.signUpButton, enabled) = [RACSignal combineLatest:@[ self.name.rac_textSignal self.email.rac_textSignal ] reduce:^(NSString *name,
NSString *email) { NSRange at = [email rangeOfString:@"@"]; return @(at.location != NSNotFound && name.length > 0); }]:
Your name Your email address Sign Up validate Newsletter
Newsletter Your name Your email address Sign Up
Newsletter Sign Up robb
Newsletter Sign Up robb
[email protected]
Sign Up
Let's talk about
Let's talk about Asynchrony
[client logInWithSuccess:^{ [client loadMeUserWithSuccess:^(SPUser *me) { [client loadFilesForUser:me withSuccess:^(NSArray *files)
{ NSLog(@"Help me, " "I'm trapped in callback hell!"); } error:^(NSError *error) { // Handle failure } } error:^(NSError *error) { // Handle failure }]; } error:^(NSError *error) { // Handle failure }]; omg, why?!
Let's fix this
1. HTTP Client
@interface SPHTTPClient : AFHTTPClient - (RACSignal *)enqueueRequest:(NSURLRequest *)req; @end
[self enqueueHTTPRequestOperation:operation]; - (RACSignal *)enqueueRequest:(NSURLRequest *)req { return [RACSignal createSignal:^(id<RACSubscriber>
subscriber) { AFHTTPRequestOperation *operation; operation = [self HTTPRequestOperationWithRequest:req success:^(id operation, id response) { [subscriber sendNext:response]; [subscriber sendCompleted]; } failure:^(id operation, NSError *error) { [subscriber sendError:error]; }];
[self enqueueHTTPRequestOperation:operation]; - (RACSignal *)enqueueRequest:(NSURLRequest *)req { return [RACSignal createSignal:^(id<RACSubscriber>
subscriber) { AFHTTPRequestOperation *operation; operation = [self HTTPRequestOperationWithRequest:req success:^(id operation, id response) { [subscriber sendNext:response]; [subscriber sendCompleted]; } failure:^(id operation, NSError *error) { [subscriber sendError:error]; }];
- (RACSignal *)enqueueRequest:(NSURLRequest *)req { return [RACSignal createSignal:^(id<RACSubscriber> subscriber) {
AFHTTPRequestOperation *operation; operation = [self HTTPRequestOperationWithRequest:req success:^(id operation, id response) { [subscriber sendNext:response]; [subscriber sendCompleted]; } failure:^(id operation, NSError *error) { [subscriber sendError:error]; }]; [self enqueueHTTPRequestOperation:operation];
- (RACSignal *)enqueueRequest:(NSURLRequest *)req { return [RACSignal createSignal:^(id<RACSubscriber> subscriber) {
AFHTTPRequestOperation *operation; operation = [self HTTPRequestOperationWithRequest:req success:^(id operation, id response) { [subscriber sendNext:response]; [subscriber sendCompleted]; } failure:^(id operation, NSError *error) { [subscriber sendError:error]; }]; [self enqueueHTTPRequestOperation:operation];
- (RACSignal *)enqueueRequest:(NSURLRequest *)req { return [RACSignal createSignal:^(id<RACSubscriber> subscriber) {
AFHTTPRequestOperation *operation; operation = [self HTTPRequestOperationWithRequest:req success:^(id operation, id response) { [subscriber sendNext:response]; [subscriber sendCompleted]; } failure:^(id operation, NSError *error) { [subscriber sendError:error]; }]; [self enqueueHTTPRequestOperation:operation];
[self enqueueHTTPRequestOperation:operation]; return [RACDisposable disposableWithBlock:^{ [operation cancel]; }]; }]; createSignal:^(id<RACSubscriber>
subscriber) { AFHTTPRequestOperation *operation; operation = [self HTTPRequestOperationWithRequest:req success:^(id operation, id response) { [subscriber sendNext:response]; [subscriber sendCompleted]; } failure:^(id operation, NSError *error) { [subscriber sendError:error]; }];
[self enqueueHTTPRequestOperation:operation]; return [RACDisposable disposableWithBlock:^{ [operation cancel]; }]; }]; createSignal:^(id<RACSubscriber>
subscriber) { AFHTTPRequestOperation *operation; operation = [self HTTPRequestOperationWithRequest:req success:^(id operation, id response) { [subscriber sendNext:response]; [subscriber sendCompleted]; } failure:^(id operation, NSError *error) { [subscriber sendError:error]; }];
2. API interaction
- (RACSignal *)fetchMeUser return [[self.client getPath:@"/me"] flattenMap:^(id JSON) { NSError
*error; SPUser *user = [SPUser userWithJSON:JSON error:&error]; if (user == nil) { return [RACSignal error:error]; } else { return [RACSignal return:user]; } }]; }
- (RACSignal *)fetchMeUser return [[self.client getPath:@"/me"] flattenMap:^(id JSON) { NSError
*error; SPUser *user = [SPUser userWithJSON:JSON error:&error]; if (user == nil) { return [RACSignal error:error]; } else { return [RACSignal return:user]; } }]; }
- (RACSignal *)fetchMeUser return [[self.client getPath:@"/me"] flattenMap:^(id JSON) { NSError
*error; SPUser *user = [SPUser userWithJSON:JSON error:&error]; if (user == nil) { return [RACSignal error:error]; } else { return [RACSignal return:user]; } }]; }
- (RACSignal *)fetchMeUser return [[self.client getPath:@"/me"] flattenMap:^(id JSON) { NSError
*error; SPUser *user = [SPUser userWithJSON:JSON error:&error]; if (user == nil) { return [RACSignal error:error]; } else { return [RACSignal return:user]; } }]; }
- (RACSignal *)fetchMeUser return [[self.client getPath:@"/me"] flattenMap:^(id JSON) { NSError
*error; SPUser *user = [SPUser userWithJSON:JSON error:&error]; if (user == nil) { return [RACSignal error:error]; } else { return [RACSignal return:user]; } }]; } check out Mantle!
- (RACSignal *)fetchMeUser return [[self.client getPath:@"/me"] flattenMap:^(id JSON) { NSError
*error; SPUser *user = [SPUser userWithJSON:JSON error:&error]; if (user == nil) { return [RACSignal error:error]; } else { return [RACSignal return:user]; } }]; }
- (RACSignal *)fetchMeUser return [[self.client getPath:@"/me"] flattenMap:^(id JSON) { NSError
*error; SPUser *user = [SPUser userWithJSON:JSON error:&error]; if (user == nil) { return [RACSignal error:error]; } else { return [RACSignal return:user]; } }]; }
3. Putting it together
[[[[client logIn] then:^{ return [client fetchMeUser]; }] flattenMap:^(SPUser *me) {
return [client fetchFilesForUser:me]; }] subscribeNext:^(NSArray *files) { NSLog(@"Files: %@", files); } error:^(NSError *error) { // Handle error }];
[[[[client logIn] then:^{ return [client fetchMeUser]; }] flattenMap:^(SPUser *me) {
return [client fetchFilesForUser:me]; }] subscribeNext:^(NSArray *files) { NSLog(@"Files: %@", files); } error:^(NSError *error) { // Handle error }];
[[[[client logIn] then:^{ return [client fetchMeUser]; }] flattenMap:^(SPUser *me) {
return [client fetchFilesForUser:me]; }] subscribeNext:^(NSArray *files) { NSLog(@"Files: %@", files); } error:^(NSError *error) { // Handle error }];
[[[[client logIn] then:^{ return [client fetchMeUser]; }] flattenMap:^(SPUser *me) {
return [client fetchFilesForUser:me]; }] subscribeNext:^(NSArray *files) { NSLog(@"Files: %@", files); } error:^(NSError *error) { // Handle error }];
[[[[client logIn] then:^{ return [client fetchMeUser]; }] flattenMap:^(SPUser *me) {
return [client fetchFilesForUser:me]; }] subscribeNext:^(NSArray *files) { NSLog(@"Files: %@", files); } error:^(NSError *error) { // Handle error }];
[[[[client logIn] then:^{ return [client fetchMeUser]; }] flattenMap:^(SPUser *me) {
return [client fetchFilesForUser:me]; }] subscribeNext:^(NSArray *files) { NSLog(@"Files: %@", files); } error:^(NSError *error) { // Handle error }];
[[[[client logIn] then:^{ return [client fetchMeUser]; }] flattenMap:^(SPUser *me) {
return [client fetchFilesForUser:me]; }] subscribeNext:^(NSArray *files) { NSLog(@"Files: %@", files); } error:^(NSError *error) { // Handle error }];
UI&IO
UI+IO
Your name Your email address Sign Up Newsletter
Your name Your email address Sign Up validate Newsletter
Your name Your email address Sign Up validate Newsletter
, why me? oh boy
self.name.rac_textSignal self.email.rac_textSignal reduce:^(NSString *name, NSString *email) { NSRange at =
[email rangeOfString:@"@"]; return @(at.location != NSNotFound && name.length > 0); }]; RAC(self.signUpButton, enabled) = [RACSignal combineLatest:@[ ]
self.name.rac_textSignal self.email.rac_textSignal reduce:^(NSString *name, NSString *email) { NSRange at =
[email rangeOfString:@"@"]; return @(at.location != NSNotFound && name.length > 0); }]; RAC(self.signUpButton, enabled) = [RACSignal combineLatest:@[ ]
validName, validEmail reduce:^(NSString *name, NSString *email) { NSRange at =
[email rangeOfString:@"@"]; return @(at.location != NSNotFound && name.length > 0); }]; reduce:^(NSString *name, NSString *email) { NSRange at = [email rangeOfString:@"@"]; return @(at.location != NSNotFound && name.length > 0); }]; RAC(self.signUpButton, enabled) = [RACSignal combineLatest:@[ ]
reduce:^(NSString *name, NSString *email) { NSRange at = [email rangeOfString:@"@"];
return @(at.location != NSNotFound && name.length > 0); }]; validName, validEmail RAC(self.signUpButton, enabled) = [RACSignal combineLatest:@[ ]
reduce:^(NSNumber *name, NSNumber *email) { return @(name.boolValue && email.boolValue); }];
validName, validEmail map:^(NSString *name) { return @(name.length > 0); }]; RAC(self.signUpButton, enabled) = [RACSignal combineLatest:@[ ]
RACSignal *validName = [self.name.rac_textSignal map:^(NSString *name) { return @(name.length >
0); }]; reduce:^(NSNumber *name, NSNumber *email) { validName, validEmail RAC(self.signUpButton, enabled) = [RACSignal combineLatest:@[ ] RACSignal *validEmail = [[self.email.rac_textSignal map:^(NSString *email) { return [[client validateEmail:email] startWith:@NO]; }] switchToLatest];
RACSignal *validName = [self.name.rac_textSignal map:^(NSString *name) { return @(name.length >
0); }]; RACSignal *validEmail = [[self.email.rac_textSignal map:^(NSString *email) { return [[client validateEmail:email] startWith:@NO]; }] switchToLatest];
RACSignal *validEmail = [[self.email.rac_textSignal map:^(NSString *email) { return [[client validateEmail:email]
startWith:@NO]; }] switchToLatest]; RACSignal *validName = [self.name.rac_textSignal map:^(NSString *name) { return @(name.length > 0); }];
RACSignal *validEmail = [[self.email.rac_textSignal map:^(NSString *email) { return [[client validateEmail:email]
startWith:@NO]; }] switchToLatest]; RACSignal *validName = [self.name.rac_textSignal map:^(NSString *name) { return @(name.length > 0); }];
Your name Your email address Sign Up validate Newsletter
Newsletter Your name Your email address Sign Up
Newsletter Sign Up robb
Newsletter Sign Up robb
[email protected]
Newsletter Sign Up robb
[email protected]
Sign Up
Recap
Recap + Declarative code
Recap + Declarative code + Easy handling of asynchronous tasks
Recap + Declarative code + Easy handling of asynchronous tasks
+ Great Composition
Recap + Declarative code + Easy handling of asynchronous tasks
+ Great Composition − Conceptual overhead
Recap + Declarative code + Easy handling of asynchronous tasks
+ Great Composition − Conceptual overhead − Debugging can get tricky
Recap (dtrace support coming soon) + Declarative code + Easy
handling of asynchronous tasks + Great Composition − Conceptual overhead − Debugging can get tricky
Qs?
Thanks!
iPhone 5 Setch Template courtesy of Denis Rojčyk Cloud icon
curtesy of Dmitry Baranovskiy, from The Noun Project