如何消除内部组件的@Output的反跳? [英] how do I debounce the @Output of an inner component?

问题描述

我有一个包装另一个组件<inner-component>并绑定到InnerComponent.innerChanged()自定义事件的组件.我想使用@output属性来冒泡，但我也想对输出进行去抖动.

I have a component that wraps another component <inner-component> and binds to the InnerComponent.innerChanged() custom event. I want to bubble up using an @output property, but I also want to debounce the output.

如何使用RxJS .debounce()或.debounceTime()来做到这一点?

How do I use RxJS .debounce() or .debounceTime() to do this?

类似这样的东西:

import {Component, Output, EventEmitter} from 'angular2/core';
import 'rxjs/add/operator/debounce';
import 'rxjs/add/operator/debounceTime';

@Component({
  selector: 'debounced-component',
  template: `
    <div>
      <h1>Debounced Outer Component</h1>
      // export class InnerComponent{
      //   @Output() innerChanged: new EventEmitter<string>();
      //   onKeyUp(value){
      //     this.innerChanged.emit(value);
      //   }
      // }
      <input #inner type="text" (innerChange)="onInnerChange(inner.value)">
    </div>
  `
})
export class DebouncedComponent {
  @Output() outerValueChanged: new EventEmitter<string>();

  constructor() {}

  onInnerChange(value) {
    this.outerValuedChanged.emit(value); // I want to debounce() this.
  }
}

推荐答案

要去抖动值，可以使用主题".主题既是可观察的，又是观察者.这意味着您可以将其视为可观察的对象，也可以将值传递给它.

To debounce values you could use a Subject. A subject is both an observable and a observer. This means you can treat it as an observable and pass values to it as well.

您可以利用它来将新值从内部组件传递给它，然后以这种方式对其进行去抖动.

You could leverage this to pass the new values from the inner-component to it and debounce it this way.

export class DebouncedComponent {
  @Output() outerValueChanged: new EventEmitter<string>();
  const debouncer: Subject<string> = new Subject<string>();

  constructor() {
      // you listen to values here which are debounced
      // on every value, you call the outer component
      debouncer
        .debounceTime(100)
        .subscribe((value) => this.outerValuedChanged.emit(value));
  }

  onInnerChange(value) {
    // send every value from the inner to the subject
    debouncer.next(value);
  }
}

这是未经测试的伪代码.您可以在此处看到该概念的有效示例( http://jsbin.com/bexiqeq/15/edit?js，console ).它没有角度，但是概念保持不变.

This is untested pseudo-code. You can see a working example of the concept here (http://jsbin.com/bexiqeq/15/edit?js,console). It's without angular but the concept remains the same.

更新:对于较新版本的Angular，您可能需要稍作改动:将debouncer.debounceTime(100)更改为debouncer.pipe(debounceTime(100))

Update: For newer versions of Angular you might need a slight: change debouncer.debounceTime(100) gets changed to debouncer.pipe(debounceTime(100))

constructor() {
      // you listen to values here which are debounced
     // on every value, you call the outer component
     debouncer
       .pipe(debounceTime(100))
       .subscribe((value) => this.outerValuedChanged.emit(value));
}

这篇关于如何消除内部组件的@Output的反跳?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！