24 - 激活的样式-指令

[tim760255458]

<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, {value}) {
    const [ styles, cb ] = value
    watchEffect(() => {
      Object.keys(styles).forEach(key => el.style[key] = cb() ? styles[key] : '')
    })
  }
}

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>