Template Refs #

While Vue's declarative rendering model abstracts away most of the direct DOM operations for you, there may still be cases where we need direct access to the underlying DOM elements. To achieve this, we can use the special ref attribute:

<input ref="input">

ref is a special attribute, similar to the key attribute discussed in the v-for chapter. It allows us to obtain a direct reference to a specific DOM element or child component instance after it's mounted. This may be useful when you want to, for example, programmatically focus an input on component mount, or initialize a 3rd party library on an element.

Accessing the Refs #

<script setup>
import { ref, onMounted } from 'vue'

// declare a ref to hold the element reference
// the name must match template ref value
const input = ref(null)

onMounted(() => {
  input.value.focus()
})
</script>

<template>
  <input ref="input" />
</template>

export default {
  setup() {
    const input = ref(null)
    // ...
    return {
      input
    }
  }
}

<script>
export default {
  mounted() {
    this.$refs.input.focus()
  }
}
</script>

<template>
  <input ref="input" />
</template>

Note that you can only access the ref after the component is mounted. If you try to access $refs.inputinput in a template expression, it will be null on the first render. This is because the element doesn't exist until after the first render!

watchEffect(() => {
  if (input.value) {
    input.value.focus()
  } else {
    // not mounted yet, or the element was unmounted (e.g. by v-if)
  }
})

Refs inside v-for #

Requires v3.2.25 or above

<script setup>
import { ref, onMounted } from 'vue'

const list = ref([
  /* ... */
])

const itemRefs = ref([])

onMounted(() => console.log(itemRefs.value))
</script>

<template>
  <ul>
    <li v-for="item in list" ref="itemRefs">
      {{ item }}
    </li>
  </ul>
</template>

<script>
export default {
  data() {
    return {
      list: [
        /* ... */
      ]
    }
  },
  mounted() {
    console.log(this.$refs.items)
  }
}
</script>

<template>
  <ul>
    <li v-for="item in list" ref="items">
      {{ item }}
    </li>
  </ul>
</template>

It should be noted that the ref array does not guarantee the same order as the source array.

Function Refs #

Instead of a string key, the ref attribute can also be bound to a function, which will be called on each component update and gives you full flexibility on where to store the element reference. The function receives the element reference as the first argument:

<input :ref="(el) => { /* assign el to a property or ref */ }">

Note we are using a dynamic :ref binding so we can pass it a function instead of a ref name string. When the element is unmounted, the argument will be null. You can, of course, use a method instead of an inline function.

Ref on Component #

This section assumes knowledge of Components. Feel free to skip it and come back later.

ref can also be used on a child component. In this case the reference will be that of a component instance:

<script setup>
import { ref, onMounted } from 'vue'
import Child from './Child.vue'

const child = ref(null)

onMounted(() => {
  // child.value will hold an instance of <Child />
})
</script>

<template>
  <Child ref="child" />
</template>

<script>
import Child from './Child.vue'

export default {
  components: {
    Child
  },
  mounted() {
    // this.$refs.child will hold an instance of <Child />
  }
}
</script>

<template>
  <Child ref="child" />
</template>

If the child component is using Options API or not using <script setup>, theThe referenced instance will be identical to the child component's this, which means the parent component will have full access to every property and method of the child component. This makes it easy to create tightly coupled implementation details between the parent and the child, so component refs should be only used when absolutely needed - in most cases, you should try to implement parent / child interactions using the standard props and emit interfaces first.

<script setup>
import { ref } from 'vue'

const a = 1
const b = ref(2)

defineExpose({
  a,
  b
})
</script>

export default {
  expose: ['publicData', 'publicMethod'],
  data() {
    return {
      publicData: 'foo',
      privateData: 'bar'
    }
  },
  methods: {
    publicMethod() {
      /* ... */
    },
    privateMethod() {
      /* ... */
    }
  }
}