ReactiveObjC（OC版ReactiveCocoa）的安装与使用

https://github.com/ReactiveCocoa/ReactiveObjC/blob/master/README.md#when-to-use-reactiveobjc

一、使用pod导入第三方库ReactiveCocoa

podfile文件内容如下：

platform :ios,'8.0'

target 'MyReactiveCocoa'do

use_frameworks!

pod 'ReactiveObjC','~> 3.1.0'

end

二、基础用法

1、将页面元素和数据绑定

// When self.username changes, logs the new name to the console.

//

// RACObserve(self, username) creates a new RACSignal that sends the current

// value of self.username, then the new value whenever it changes.

// -subscribeNext: will execute the block whenever the signal sends a value.

@weakify(self)

[RACObserve(self.person, name)

subscribeNext:^(id x){

@strongify(self)

self.lblName.text = x;

}];

2、定制条件约束信号量发出的情况

// Only logs names that starts with "j".

//

// -filter returns a new RACSignal that only sends a new value when its block

// returns YES.

[[RACObserve(self.person, name) filter:^BOOL(NSString *value) {

return [value hasPrefix:@"j"];

}] subscribeNext:^(id_Nullable x) {

self.lblName.text = x;

}];

3、单向绑定

// Creates a one-way binding so that self.createEnabled will be

// true whenever self.password and self.passwordConfirmation

// are equal.

//

// RAC() is a macro that makes the binding look nicer.

//

// +combineLatest:reduce: takes an array of signals, executes the block with the

// latest value from each signal whenever any of them changes, and returns a new

// RACSignal that sends the return value of that block as values.

RAC(self, createEnabled) = [RACSignal combineLatest:@[ RACObserve(self, password), RACObserve(self, passwordConfirmation) ]

reduce:^(NSString *password, NSString *passwordConfirm) {

return @([passwordConfirm isEqualToString:password]);

}];

3、给button添加点击事件

// Logs a message whenever the button is pressed.

//

// RACCommand creates signals to represent UI actions. Each signal can

// represent a button press, for example, and have additional work associated

// with it.

//

// -rac_command is an addition to NSButton. The button will send itself on that

// command whenever it's pressed.

self.button.rac_command = [[RACCommand alloc] initWithSignalBlock:^(id _) {

NSLog(@"button was pressed!");

return [RACSignal empty];

}];

4、