Template Ref Unwrapping Only Works for Top-Level Properties
Impact: MEDIUM - Vue only auto-unwraps refs that are top-level properties in the template render context. Nested refs (refs inside objects) are NOT unwrapped in expressions, causing [object Object] rendering or calculation errors.
This caveat trips up developers when they store refs inside reactive objects or plain objects and try to use them in template expressions like {{ object.count + 1 }}.
Task Checklist
- Keep refs at the top level of your setup return or script setup
- Destructure nested refs to top-level variables before using in expressions
- Be aware that text interpolation
{{ object.ref }}DOES unwrap, but expressions{{ object.ref + 1 }}do NOT - Consider restructuring data to avoid nested refs in templates
Incorrect:
<script setup>
import { ref } from 'vue'
const count = ref(0)
const object = { id: ref(1) }
</script>
<template>
<!-- WRONG: Nested ref in expression - does NOT unwrap -->
<p>ID + 1 = {{ object.id + 1 }}</p>
<!-- Renders: "ID + 1 = [object Object]1" -->
<!-- Surprisingly, plain interpolation DOES work -->
<p>ID = {{ object.id }}</p>
<!-- Renders: "ID = 1" (unwrapped because it's the final expression) -->
</template>Correct:
<script setup>
import { ref } from 'vue'
const count = ref(0)
const object = { id: ref(1) }
// SOLUTION 1: Destructure to top-level
const { id } = object
</script>
<template>
<!-- CORRECT: Top-level ref unwraps in all expressions -->
<p>Count + 1 = {{ count + 1 }}</p>
<!-- Renders: "Count + 1 = 1" -->
<!-- CORRECT: Destructured ref is now top-level -->
<p>ID + 1 = {{ id + 1 }}</p>
<!-- Renders: "ID + 1 = 2" -->
</template><script setup>
import { ref, computed } from 'vue'
const object = { id: ref(1) }
// SOLUTION 2: Use computed for derived values
const idPlusOne = computed(() => object.id.value + 1)
</script>
<template>
<!-- CORRECT: Computed handles the .value access -->
<p>ID + 1 = {{ idPlusOne }}</p>
</template><script setup>
import { reactive } from 'vue'
// SOLUTION 3: Use reactive object instead (refs inside reactive auto-unwrap)
const object = reactive({ id: 1 })
</script>
<template>
<!-- CORRECT: Plain reactive property works in expressions -->
<p>ID + 1 = {{ object.id + 1 }}</p>
</template>// WHY this happens:
// - Template compilation only adds .value to top-level identifiers
// - {{ count + 1 }} compiles to: count.value + 1
// - {{ object.id + 1 }} compiles to: object.id + 1 (no .value added!)
// - Plain {{ object.id }} has special handling for display purposes