Angular防抖指令

第一次在掘金上记笔记，使用Angular小半年了。深感Angular中文资料稀少，故记录一些文章供自己翻阅，同时希望能帮助到一些有需要的朋友

目标：在元素上直接对click等事件进行防抖处理

思路：

• RxJS debounceTime操作符
• angular HostListener监听事件

在线示例stackblitz

代码实现：

防抖测试

import { Directive, Input, OnDestroy, OnInit } from '@angular/core';
import { debounceTime, Subject, takeUntil } from 'rxjs';

@Directive()
export abstract class AbstractDebounceDirective implements OnInit, OnDestroy {
  @Input() debounceTime = 300;

  protected emitEvent$ = new Subject();

  protected destroyed$ = new Subject();

  ngOnInit(): void {
    this.emitEvent$
      .pipe(debounceTime(this.debounceTime), takeUntil(this.destroyed$))
      .subscribe((value) => this.emitValue(value));
  }

  abstract emitValue(event: Event): void;

  ngOnDestroy(): void {
    this.destroyed$.next();
    this.destroyed$.complete();
  }
}

import { Directive, EventEmitter, HostListener, Output } from '@angular/core';
import { AbstractDebounceDirective } from './abstract-debounce.directive';

@Directive({
  // eslint-disable-next-line @angular-eslint/directive-selector
  selector: '[debounceKeyUp]',
})
export class DebounceKeyupDirective extends AbstractDebounceDirective {
  @Output() debounceKeyUp = new EventEmitter();

  constructor() {
    super();
  }

  @HostListener('keyup', ['$event'])
  onClick(event: KeyboardEvent): void {
    event.preventDefault();
    this.emitEvent$.next(event);
  }

  emitValue(event: Event): void {
    this.debounceKeyUp.emit(event);
  }
}

import { Directive, EventEmitter, HostListener, Output } from '@angular/core';
import { AbstractDebounceDirective } from './abstract-debounce.directive';

@Directive({
  // eslint-disable-next-line @angular-eslint/directive-selector
  selector: '[debounceClick]',
})
export class DebounceClickDirective extends AbstractDebounceDirective {
  @Output() debounceClick = new EventEmitter();

  constructor() {
    super();
  }

  @HostListener('click', ['$event'])
  onClick(event: MouseEvent): void {
    event.preventDefault();
    this.emitEvent$.next(event);
  }

  emitValue(event: Event): void {
    this.debounceClick.emit(event);
  }
}