24 - 激活的样式-指令

[izilongwan]

<script setup lang='ts'>

import { ref, watch } from "vue"

/**
 * Implement the custom directive
 * Make sure the list item text color changes to red when the `toggleTab` is toggled
 *
*/
const VActiveStyle = {
  mounted: doActive,
}

function doActive(el, {value: [style, cb]}) {
  watch(() => cb(), val => {
    el.style.cssText = val ? getCssText(style) : '';
  }, {deep: 1, immediate: true})

}

function getCssText(obj) {
  return Object.entries(obj).map(([k, v]) => `${k}:${v}`).join(';')
}

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>