20 - 节流点击指令

[webfanrc]

<script setup lang='ts'>

/**
 * Implement the custom directive
 * Make sure the `onClick` method only gets triggered once when clicked many times quickly
 * And you also need to support the debounce delay time option. e.g `v-debounce-click:ms`
 *
*/



function debounce(fn: Function, delay: number) {
  let timer = null
  return function () {
    if (timer) {
      clearTimeout(timer)
    }
    timer = setTimeout(fn, delay)
  }
}

let debounced;
const VDebounceClick = {
  created(el, binding) {
    const { value: cb, arg: delay } = binding
    debounced = debounce(cb, delay)
    el.addEventListener('click', debounced)

  },
  unmounted(el) {
    if (el._debounced) {
      el.removeEventListener('click', debounced)
    }
  },
}

function onClick() {
  console.log("Only triggered once when clicked many times quickly")
}

</script>

<template>
  <button v-debounce-click:200="onClick">
    Click on it many times quickly
  </button>
</template>