slashhuang / dive-into-rxjs

A guide for rxJS with source code analysis

dive-into-rxjs

对rxjs 5的使用编写demo示例并对rxJS的设计**做简单分析

由于rxjs 5已由版本4迁移，部分api的名字有些变更，需要开发者注意

rxjs4 迁移至 rxjs5 文档

主程序示例代码在'''/example/*.js'''下面

参考文档

learn rxjs reactive io reactive programming

使用

  $ cnpm install
  $ npm start

rxjs核心理念分层

    Observable:
        proveider ==> 事件或者数据源invokable

    Observer:
        consumer ==> 监听observerable的信息分发

    Subscription:
        执行Observable的数据

    Operators:
        纯函数，以函数式风格处理数据，比如map, filter, concat, flatMap等操作符.

    Subject:
        和eventEmitter基本相同，唯一的方式分发数据或者事件到多个Observer.

    Schedulers:
        中心化处理并发，允许我们协调计算。比如e.g. setTimeout or requestAnimationFrame or others.

核心**

1. Observerable核心

Observable=>Observer: Subscribing to an Observable is analogous to calling a Function.

    Creating Observables
    Subscribing to Observables
    Executing the Observable
    Disposing Observables

why rxjs

1. purity: 采用纯函数加工数据

    //老的写法
    var count = 0;
    var button = document.querySelector('button');
    button.addEventListener('click', () => console.log(`Clicked ${++count} times`));

    //对比
    var button = document.querySelector('button');
    Rx.Observable.fromEvent(button, 'click')
        //https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/scan.md
      .scan(count => count + 1, 0)
      .subscribe(count => console.log(`Clicked ${count} times`));

2. flow: 通知机制的流式处理

    // 以典型的button每秒点击为例。 采用rx提供的throttleTime操作符
    const button = document.querySelector('button');
    Rx.Observable.fromEvent(button, 'click')
      .throttleTime(1000)
      .scan(count => count + 1, 0)
      .subscribe(count => console.log(`Clicked ${count} times`));

类似的operator

    filter, delay, debounceTime, take, takeUntil, distinct, distinctUntilChanged etc.

3. values: 数据处理

    const button = document.querySelector('button');
    Rx.Observable.fromEvent(button, 'click')
      .throttleTime(1000)
      .map(event => event.clientX)
      .scan((count, clientX) => count + clientX, 0)
      .subscribe(count => console.log(count))

类似的operator

    pluck, pairwise, sample etc.

核心概念分解

Observable

rxJS的各种api命名和lodash很像

rxJS的通知执行机制python的generator很类似，

在程序流上面能够很好的和PromiseA+库等保持兼容性

本项目持续更新中，欢迎提出PR

rxjs 5 github文档

Copyright

Copyright (C) 2016 ~ slashhuang [e-mail]