OC+RAC(六) 核心方法bind

-(void)_test6{
    RACSignal *signal = [RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
        [subscriber sendNext:@"first value"];
        [subscriber sendNext:@"second value"];
        [subscriber sendNext:@"third value"];
        [subscriber sendCompleted];
        return nil;
    }];

    RACSignal *bindSignal = [signal bind:^RACSignalBindBlock{

        return  ^RACSignal *(id value, BOOL *stop) {

            NSString *oValue = value;
            if ([oValue isEqualToString:@"first value"]) {
                return [RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
                    [subscriber sendNext:@"first value bind after"];
                    [subscriber sendCompleted];
                    return nil;
                }];
            }

            if ([oValue isEqualToString:@"second value"]) {
                *stop = YES;
                return [RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
                    [subscriber sendNext:@"second value bind after"];
                    [subscriber sendCompleted];
                    return nil;
                }];
            }

            if ([oValue isEqualToString:@"third value"]) {
                return [RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
                    [subscriber sendNext:@"third value bind after"];
                    [subscriber sendCompleted];
                    return nil;
                }];
            }

            return nil;
        };
    }];

    [bindSignal subscribeNext:^(id  _Nullable x) {

        NSLog(@"x====%@",x);
    }];

}

再来一个例子：

-(void)_test7{
    //1.创建信号
    RACSubject * subject = [RACSubject subject];

    //2.绑定信号
    RACSignal * bindSignal = [subject bind:^RACSignalBindBlock _Nonnull{

        return ^RACSignal * (id value, BOOL *stop){
            NSLog(@"%@",value);
            return [RACReturnSignal return:[NSString stringWithFormat:@"一顿操作猛如虎 %@",value]];

        };
    }];

    //3.订阅信号
    [bindSignal subscribeNext:^(id  _Nullable x) {
        NSLog(@"绑定接收到!! %@",x);
    }];

    //4.发送
    [subject sendNext:@"发送原始的数据"];
}