![- (void) updateChangeAnswerButtonText {
if (self.didAnswerQuestion && self.inResultsView) {
[self.commentHeaderCell configureWithStyle:TCQuestionDetailCommentHeaderCellChangeAnswer];
} else if (self.isOwnerOfQuestion && !self.didAnswerQuestion && self.inResultsView) {
[self.commentHeaderCell configureWithStyle:TCQuestionDetailCommentHeaderCellViewAnswers];
} else {
[self.commentHeaderCell configureWithStyle:TCQuestionDetailCommentHeaderCellViewStats];
}
}
- (void) updateViewCommentStatus {
if ((self.didAnswerQuestion || self.isOwnerOfQuestion) && !self.commentsAreShowing) {
self.commentsAreShowing = YES;
- (void) prepareForReuse {
self.commentsLoadingShowing = YES;
self.state = TCQuestionDetailViewContro
…
self.questionFullyLoaded = NO;
}
self.isOwnerOfQuestion = NO;
self.didAnswerQuestion = NO;
[self showCommentBox:self.inResultsView || self.isOwnerOfQuestion];
[self showCommentBox:NO];
}
self.loadingNextPageOfComments = NO;
self.commentsAreShowing = NO;
self.commentsLoadingShowing = NO;
!
^aBlock {
sself.didAnswerQuestion = sself.question.userResponse ? YES : NO;
sself.inResultsView = sself.didAnswerQuestion || self.isOwnerOfQuestion;
if (sself.questionFullyLoaded) {
return;
} …
}
}
l co
Rea
rom
ef
d
file
one](https://image.slidesharecdn.com/reactivecocoalightningtalk-131116195801-phpapp02/85/Reactive-Cocoa-Lightning-Talk-12-320.jpg)
![- (void)viewDidLoad {
[super viewDidLoad];
[self.username
addTarget:self
action:@selector(textFieldTextDidChange:)
forControlEvents:UIControlEventAllEditingEvents];
[self.email
addTarget:self
action:@selector(textFieldTextDidChange:)
forControlEvents:UIControlEventAllEditingEvents];
Your name
Your email address
Sign Up
abled
ton.en
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gnUpB
si
}
!
- (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;
}
Old
Solved the imperative way.](https://image.slidesharecdn.com/reactivecocoalightningtalk-131116195801-phpapp02/85/Reactive-Cocoa-Lightning-Talk-16-320.jpg)
![Your name
Your email address
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);
}];
Sign Up
ould I
Sh
SOME
AWE
bled?
e ena
b
Solved the reactive way.](https://image.slidesharecdn.com/reactivecocoalightningtalk-131116195801-phpapp02/85/Reactive-Cocoa-Lightning-Talk-17-320.jpg)
![Your name
Your email address
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);
}];
Sign Up
ould I
Sh
SOME
AWE
bled?
e ena
b
Solved the reactive way.](https://image.slidesharecdn.com/reactivecocoalightningtalk-131116195801-phpapp02/85/Reactive-Cocoa-Lightning-Talk-18-320.jpg)
![Network Validation?
Easy.
Your name
Your email address
Sign Up
RACSignal *validateEmailSignal = [self.email.rac_textSignal
map:^id(NSString *emailString) {
return [MyAPI validatedEmail:emailString];
}];
uld I
Sho
bled?
be ena
!
RAC(self.signUpButton, enabled) = [RACSignal
combineLatest:@[
self.name.rac_textSignal,
validateEmailSignal
]
reduce:^(NSString *name, APIResponse *response) {
return @(response.json.isValid == YES && name.length > 0);
}];
SOME
AWE
Solved the reactive way.](https://image.slidesharecdn.com/reactivecocoalightningtalk-131116195801-phpapp02/85/Reactive-Cocoa-Lightning-Talk-19-320.jpg)
![Network Validation?
Easy.
Your name
Your email address
Sign Up
RACSignal *validateEmailSignal =
map
}];
!
uld I
Sho
The point is to Minimize State
RAC
combineLatest
]
reduce
}];
Solved the
SOME
AWE
bled?
be ena](https://image.slidesharecdn.com/reactivecocoalightningtalk-131116195801-phpapp02/85/Reactive-Cocoa-Lightning-Talk-20-320.jpg)
![Network Validation?
Easy.
Your name
Your email address
Sign Up
RACSignal *validateEmailSignal =
map
}];
!
uld I
Sho
The point is to Minimize State
RAC
combineLatest
]
reduce
}];
Solved the
SOME
AWE
bled?
be ena](https://image.slidesharecdn.com/reactivecocoalightningtalk-131116195801-phpapp02/85/Reactive-Cocoa-Lightning-Talk-21-320.jpg)
Reactive Cocoa Lightning Talk
- 1. ReactiveCocoa Bob Spryn LoHi Labs @sprynmr (github, twitter) ! ! ! https://github.com/ReactiveCocoa/ReactiveCocoa
- 2. ReactiveCocoa • An implementation of functional reactive programming • It provides APIs for composing and transforming streams of values • “Signals” send you these values over time for you to react to http://en.wikipedia.org/wiki/Functional_reactive_programming
- 3. ?
- 4. Not just another API. It enables you to Program Smarter Focus on WHAT not HOW
- 5. Reactive!!! Declarative!!! What does that even mean?
- 6. • Setup your reactions • Compose, Reactive!!! Declarative!!! split, filter, etc. What does that even mean?
- 7. Imperative The way we normally program.
- 8. Imperative The way we normally program. • Observe, wait, then command & control • Dealing with the HOW, not just the WHAT • Code for controlling flow is spread all over
- 9. Auto-layout : Managing Frames ReactiveCocoa : Imperative programming
- 11. BOOL loadingNextPageOfComments; 2 states BOOL commentsAreShowing; 4 states BOOL commentsLoadingShowing; 8 states BOOL flippingAnswers; 16 states BOOL isOwnerOfQuestion; 32 states
- 12. - (void) updateChangeAnswerButtonText { if (self.didAnswerQuestion && self.inResultsView) { [self.commentHeaderCell configureWithStyle:TCQuestionDetailCommentHeaderCellChangeAnswer]; } else if (self.isOwnerOfQuestion && !self.didAnswerQuestion && self.inResultsView) { [self.commentHeaderCell configureWithStyle:TCQuestionDetailCommentHeaderCellViewAnswers]; } else { [self.commentHeaderCell configureWithStyle:TCQuestionDetailCommentHeaderCellViewStats]; } } - (void) updateViewCommentStatus { if ((self.didAnswerQuestion || self.isOwnerOfQuestion) && !self.commentsAreShowing) { self.commentsAreShowing = YES; - (void) prepareForReuse { self.commentsLoadingShowing = YES; self.state = TCQuestionDetailViewContro … self.questionFullyLoaded = NO; } self.isOwnerOfQuestion = NO; self.didAnswerQuestion = NO; [self showCommentBox:self.inResultsView || self.isOwnerOfQuestion]; [self showCommentBox:NO]; } self.loadingNextPageOfComments = NO; self.commentsAreShowing = NO; self.commentsLoadingShowing = NO; ! ^aBlock { sself.didAnswerQuestion = sself.question.userResponse ? YES : NO; sself.inResultsView = sself.didAnswerQuestion || self.isOwnerOfQuestion; if (sself.questionFullyLoaded) { return; } … } } l co Rea rom ef d file one
- 13. ReactiveCocoa to the Rescue! • Signals instead of mutable variables • RACSignal – Think of it as a beacon sending out new values to it’s subscribers
- 14. RACSignal • A unified interface for observing and reacting to all kinds of events and their values • UI Action • Async Network Call • KVO • Async Processing t’s I in ll a t! pu
- 15. RACSignal • Shared vocabulary for transforming the received values • • Combine, filter, reduce, map, and many more operations Eventually generate output (side effects) • Updating a label • Update an array with objects from the network • etc.
- 16. - (void)viewDidLoad { [super viewDidLoad]; [self.username addTarget:self action:@selector(textFieldTextDidChange:) forControlEvents:UIControlEventAllEditingEvents]; [self.email addTarget:self action:@selector(textFieldTextDidChange:) forControlEvents:UIControlEventAllEditingEvents]; Your name Your email address Sign Up abled ton.en ut gnUpB si } ! - (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; } Old Solved the imperative way.
- 17. Your name Your email address 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); }]; Sign Up ould I Sh SOME AWE bled? e ena b Solved the reactive way.
- 18. Your name Your email address 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); }]; Sign Up ould I Sh SOME AWE bled? e ena b Solved the reactive way.
- 19. Network Validation? Easy. Your name Your email address Sign Up RACSignal *validateEmailSignal = [self.email.rac_textSignal map:^id(NSString *emailString) { return [MyAPI validatedEmail:emailString]; }]; uld I Sho bled? be ena ! RAC(self.signUpButton, enabled) = [RACSignal combineLatest:@[ self.name.rac_textSignal, validateEmailSignal ] reduce:^(NSString *name, APIResponse *response) { return @(response.json.isValid == YES && name.length > 0); }]; SOME AWE Solved the reactive way.
- 20. Network Validation? Easy. Your name Your email address Sign Up RACSignal *validateEmailSignal = map }]; ! uld I Sho The point is to Minimize State RAC combineLatest ] reduce }]; Solved the SOME AWE bled? be ena
- 21. Network Validation? Easy. Your name Your email address Sign Up RACSignal *validateEmailSignal = map }]; ! uld I Sho The point is to Minimize State RAC combineLatest ] reduce }]; Solved the SOME AWE bled? be ena
- 22. Check out ReactiveCocoa Your Brain Will Thank You https://github.com/ReactiveCocoa/ReactiveCocoa Bob Spryn LoHi Labs @sprynmr (github, twitter) ! Thanks to @jspahrsummers, @joshaber, @AshFurrow, @robb, @andrewsardone and @erikprice (github usernames) for sharing their presentation slides and helping me learn ReactiveCocoa