Observables provide support for passing messages between publishers and subscribers in your application. Observables offer significant benefits over other techniques for event handling, asynchronous programming, and handling multiple values.[1.]
关于 RxJS 框架的介绍和应用可以参考另外几篇文章
- RxJS Basic
- RxJS Patterns - Error Handling Patterns in High Speed Railway Client
- RxJS Patterns - Implementing Async Lock
Basic
我们来简单看一下 Observable 基本流程
Pattern: Observable => Subscriber => Subscription
const timer = new Observable((observer) => {
let interval = setInterval(()=>
observer.next(new Date(), 1000)
);
return {
unsubscribe() {
clearInterval(interval);
}
};
});
const timerSubscription = timer.subscribe({
next(t) { console.log('Current time: ', t); },
error(msg) { console.log('Error Getting Time: ', msg); }
});
// Stop listening for location after 10 seconds
setTimeout(() => { timerSubscription.unsubscribe(); }, 10000);
Observables in Angular
Angular 为他的很多常用异步操作都实现了 Observable ， 这包括
EventEmitterclass extends Observable- The HTTP module uses observables to handle AJAX requests and responses.
- The Router and Forms modules use observables to listen for and respond to user-input events.
Comments