24 - v-active-style

[topul]

// your answers
<script setup lang='ts'>

import { ref, watchEffect } from "vue"

/**
 * Implement the custom directive
 * Make sure the list item text color changes to red when the `toggleTab` is toggled
 *
*/
const VActiveStyle = {
  mounted(el, binding) {
    const [styles, callback] = binding.value
    watchEffect(() => {
      Object.keys(styles).forEach(style => {
        el.style[style] = callback() ? styles[style] : ''
      })
    })
  }
}

const list = [1, 2, 3, 4, 5, 6, 7, 8]
const activeTab = ref(0)
function toggleTab(index: number) {
  activeTab.value = index
}

</script>

<template>
  <ul>
    <li
      v-for="(item,index) in list"
      :key="index"
      v-active-style="[{'color':'red'},() => activeTab === index]"
      @click="toggleTab(index)"
    >
      {{ item }}
    </li>
  </ul>
</template>

参考文档：https://vuejs.org/guide/reusability/custom-directives.html#introduction