npm i @vueuse/core # yarn add @vueuse/core

<script src="https://unpkg.com/@vueuse/shared"></script>
<script src="https://unpkg.com/@vueuse/core"></script>

// 從 VueUse 導入的示例
import { useRefHistory } from '@vueuse/core'

<template>
  <p> 
    <button> Undo </button>
    <button> Redo </button>
  </p>
  <textarea v-model="text"/>
</template>

<script setup>
import { ref } from 'vue'
const text = ref('')
</script>

<style scoped>
  button {
    border: none;
    outline: none;
    margin-right: 10px;
    background-color: #2ecc71;
    color: white;
    padding: 5px 10px;;
  }
</style>

import { ref } from 'vue'
import { useRefHistory } from '@vueuse/core'

const text = ref('')
const { history, undo, redo } = useRefHistory(text)

<template>
  <p> 
    <button @click="undo"> Undo </button>
    <button @click="redo"> Redo </button>
  </p>
  <textarea v-model="text"/>
  <ul>
    <li v-for="entry in history" :key="entry.timestamp">
      {{ entry }}
    </li>
  </ul>
</template>

<script setup>
import { ref } from 'vue'
import { useRefHistory } from '@vueuse/core'
const text = ref('')
const { history, undo, redo } = useRefHistory(text)
</script>

<style scoped>
  button {
    border: none;
    outline: none;
    margin-right: 10px;
    background-color: #2ecc71;
    color: white;
    padding: 5px 10px;;
  }
</style>

const { history, undo, redo } = useRefHistory(text, {
  deep: true,
  capacity: 10,
})

<template>
  <button @click="open = true"> Open Popup </button>
  <div class="popup" v-if='open'>
    <div class="popup-content" ref="popup">
      Lorem ipsum dolor sit amet consectetur adipisicing elit. Corporis aliquid autem reiciendis eius accusamus sequi, ipsam corrupti vel laboriosam necessitatibus sit natus vero sint ullam! Omnis commodi eos accusantium illum?
    </div>
  </div>
</template>
 
 
<script setup>
import { ref } from 'vue'
import { onClickOutside } from '@vueuse/core'
const open = ref(false) // state of our popup
const popup = ref() // template ref
// whenever our popup exists, and we click anything BUT it
onClickOutside(popup, () => {
  open.value  = false
})
</script>
 
 
<style scoped>
  button {
    border: none;
    outline: none;
    margin-right: 10px;
    background-color: #2ecc71;
    color: white;
    padding: 5px 10px;;
  }
  .popup {
    position: fixed;
    top: ;
    left: ;
    width: 100vw;
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(, , , 0.1);
  }
  .popup-content {
    min-width: 300px;
    padding: 20px;
    width: 30%;
    background: #fff;
  }
</style>

<template>
    <div>
        <input 
            type="text" 
            :value="data"
            @input="update"
        />
    </div>
</template>
 
 
<script>
import { useVModel } from '@vueuse/core'
export default {
  props: ['data'],
  setup(props, { emit }) {
    const data = useVModel(props, 'data', emit)
    console.log(data.value) // equal to props.data
    data.value = 'name' // equal to emit('update:data', 'name')
    const update = (event) => {
        data.value = event.target.value
    }
    return {
        data,
        update
    }
  },
}
</script>

<template>
  <div>
    <p> {{ data }} </p>
    <custom-input 
      :data="data" 
      @update:data="data = $event"
    />
  </div>
</template>
 
 
<script>
import CustomInput from './components/CustomInput.vue'
import { ref } from 'vue'
export default {
  components: {
    CustomInput,
  },
  setup () {
    const data = ref('hello')
    return {
      data
    }
  }
}

<template>
  <p> Is target visible? {{ targetIsVisible }} </p>
  <div class="container">
    <div class="target" ref="target">
      <h1>Hello world</h1>
    </div>
  </div>
</template>
 
 
<script>
import { ref } from 'vue'
import { useInterpObserver } from '@vueuse/core'
export default {
  setup() {
    const target = ref(null)
    const targetIsVisible = ref(false)
    const { stop } = useInterpObserver(
      target,
      ([{ isIntersecting }], observerElement) => {
        targetIsVisible.value = isIntersecting
      },
    )
    return {
      target,
      targetIsVisible,
    }
  },
}
</script>
 
 
<style scoped>
.container {
  width: 80%;
  margin:  auto;
  background-color: #fafafa;
  max-height: 300px;
  overflow: scroll;
}
.target {
  margin-top: 500px;
  background-color: #1abc9c;
  color: white;
  padding: 20px;
}
</style>

//useInterpObserver 的選項
const { stop } = useInterpObserver(
      target,
([{ isIntersecting }], observerElement) => {
        targetIsVisible.value = isIntersecting
      },
      {
// root, rootMargin, threshold, window
// full options in the source: https://github.com/vueuse/vueuse/blob/main/packages/core/useInterpObserver/index.ts
        threshold: 0.5,
      }
)

//停止 InterpObserver
const { stop } = useInterpObserver(
      target,
      ([{ isIntersecting }], observerElement) => {
        targetIsVisible.value = isIntersecting
        if (isIntersecting) {
          stop()
        }
      },
    )

// 使用轉換代碼
<script setup>
import { ref } from 'vue'
import { useTransition, TransitionPresets } from '@vueuse/core'
 
 
const source = ref(0)
 
 
const output = useTransition(source, {
  duration: 3000,
  transition: TransitionPresets.easeOutExpo,
})
 
 
source.value = 5000
</script>

<template>
  <h2> 
    <p> Join over </p>
    <p> {{ Math.round(output) }}+ </p>
    <p>Developers </p>
  </h2>
</template>
 
 
<script setup>
import { ref } from 'vue'
import { useTransition, TransitionPresets } from '@vueuse/core'
const source = ref()
const output = useTransition(source, {
  duration: 3000,
  transition: TransitionPresets.easeOutExpo,
})
source.value = 5000
</script>

<template>
<h2 :style="{ color: color } "> COLOR CHANGING </h2>
</template>
<script setup>
import { ref, computed } from 'vue'
import { useTransition, TransitionPresets } from '@vueuse/core'
const source = ref([, , ])
const output = useTransition(source, {
duration: 3000,
transition: TransitionPresets.easeOutExpo,
})
const color = computed(() => {
const [r, g, b] = output.value
return `rgb(${r}, ${g}, $)`
})
source.value = [255, , 255]
</script>