ReactiveObjc(I)

RAC 函数式响应式编程框架

类似的框架：Masonry、AFNetworking、

订阅信号

- (void) reactiveObjTest {
    //1.订阅信号    -- 在实际开发中，就是提供给外界订阅的
    /*
     创建一个可变数组变量 _subscribers
     */
    RACSubject *subject = [RACSubject subject];
    
    //2.订阅信号    -- 代理\通知对比
    //相当于代理 objc.delegate = self;
    /*
     调用这个方法所做的事情
     1. 创建订阅者对象
     2. 将Block放到订阅者对象中
     3. 将订阅者对象放到_subscriber数组里面
     */
    [subject subscribeNext:^(id  _Nullable x) {//调用这个方法的返回值，可以用来取消订阅
        NSLog(@"%@", x);
    }];
    
    //3.注册信号
    /*
     遍历信号对象中的数组，取出订阅者，调用订阅者对象中的Block，然后执行
     */
    [subject sendNext:@"O(∩_∩)O哈！"];
    
    
}

输出：2019-06-06 15:34:46.583177+0800 Genealogy[6591:256569] O(∩_∩)O哈！

源码：

+ (instancetype)subject {
    return [[self alloc] init];
}

- (instancetype)init {
    self = [super init];
    if (self == nil) return nil;
        
    //取消订阅信号
    _disposable = [RACCompoundDisposable compoundDisposable];
    _subscribers = [[NSMutableArray alloc] initWithCapacity:1];
    
    return self;
}

- (void)dealloc {
    //取消订阅
    [self.disposable dispose];
}


- (RACDisposable *)subscribeNext:(void (^)(id x))nextBlock {
    NSCParameterAssert(nextBlock != NULL);
    
    RACSubscriber *o = [RACSubscriber subscriberWithNext:nextBlock error:NULL completed:NULL];
    return [self subscribe:o];
}


+ (instancetype)subscriberWithNext:(void (^)(id x))next error:(void (^)(NSError *error))error completed:(void (^)(void))completed {
    RACSubscriber *subscriber = [[self alloc] init];

    //next block保存在我们新创建的订阅者subscriber中了
    subscriber->_next = [next copy];
    subscriber->_error = [error copy];
    subscriber->_completed = [completed copy];

    return subscriber;
}

对私有方法进行订阅

GFamilyView.h

#import <UIKit/UIKit.h>

NS_ASSUME_NONNULL_BEGIN

@interface GFamilyView : UIView

@end

NS_ASSUME_NONNULL_END

GFamily.m

@interface GFamilyView ()

@property(nonatomic, retain)UIButton *buildFamilyBtn;

@end

@implementation GFamilyView

- (void) buildFamilyAction:(UIButton *)sender {

}

@end

GMyFamilyController.m调用

- (void)viewDidLoad {
    [super viewDidLoad];
    self.navigationItem.title = @"我的家族";
    
    [self addSubViews];
    
    //这里使用了运行时，调用其私有的方法
    [[self.familyView rac_signalForSelector:@selector(buildFamilyAction:)] subscribeNext:^(RACTuple * _Nullable x) {//x 是buildFamilyAction参数的集合
        NSLog(@"观察到了按钮点击！");
    }];
}

输出：
2019-06-06 17:13:19.408324+0800 Genealogy[7979:352547] 观察到了按钮点击！

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RAC的KVO

导入文件：#import <NSObject+RACKVOWrapper.h>

GMyFamilyController.m 文件

- (void)viewDidLoad {
    [super viewDidLoad];
    self.navigationItem.title = @"我的家族";
    
//函数式编程思想
    [self.familyView rac_observeKeyPath:@"frame" options:NSKeyValueObservingOptionNew observer:self block:^(id value, NSDictionary *change, BOOL causedByDealloc, BOOL affectedOnlyLastComponent) {
        //
        NSLog(@"%@", change);
    }];
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    self.familyView.frame = CGRectMake(0, 0, 50, 50);
}

输出：
2019-06-06 18:04:55.406959+0800 Genealogy[8733:402957] { kind = 1; new = "NSRect: {{0, 0}, {50, 50}}"; }

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转载于:https://www.jianshu.com/p/a4955053792e