3.2 KiB
3.2 KiB
title, impact, impactDescription, type, tags
| title | impact | impactDescription | type | tags | |||||
|---|---|---|---|---|---|---|---|---|---|
| Teleport Target Must Exist Before Mount | HIGH | Teleport will fail silently or throw errors if target element doesn't exist when component mounts | gotcha |
|
Teleport Target Must Exist Before Mount
Impact: HIGH - The teleport to target must already exist in the DOM when the <Teleport> component is mounted. If the target doesn't exist, Vue will throw an error and the teleported content won't render.
This is a common source of bugs when using modals, tooltips, or other teleported UI elements, especially when targeting Vue-rendered elements.
Task Checklist
- Ensure teleport target exists in the DOM before
<Teleport>mounts - Place teleport containers (e.g.,
#modals,#tooltips) inindex.htmloutside the Vue app - If targeting Vue-rendered elements, ensure they mount before the Teleport
- Use Vue 3.5+
deferprop when target is rendered later in the same component tree
Incorrect:
<template>
<!-- ERROR: Target doesn't exist yet when Teleport mounts -->
<Teleport to="#modal-container">
<div class="modal">Modal content</div>
</Teleport>
<!-- Target is defined after the Teleport -->
<div id="modal-container"></div>
</template>
Correct - Option 1: External container in index.html:
<!-- index.html -->
<body>
<div id="app"></div>
<!-- Container exists before Vue app mounts -->
<div id="modals"></div>
<div id="tooltips"></div>
</body>
<template>
<!-- Safe: #modals exists before any Vue component mounts -->
<Teleport to="#modals">
<div v-if="showModal" class="modal">Modal content</div>
</Teleport>
</template>
Correct - Option 2: Teleport to body:
<template>
<!-- Safe: body always exists -->
<Teleport to="body">
<div v-if="showModal" class="modal">Modal content</div>
</Teleport>
</template>
Correct - Option 3: Vue 3.5+ defer prop:
<template>
<!-- Works in Vue 3.5+: defer resolves target after other parts mount -->
<Teleport defer to="#late-container">
<div class="modal">Modal content</div>
</Teleport>
<!-- Target rendered later in template -->
<div id="late-container"></div>
</template>
Defer Prop Limitations (Vue 3.5+)
The defer prop only waits for elements rendered in the same mount/update tick:
<template>
<!-- ERROR: defer won't help if target mounts asynchronously -->
<Teleport defer to="#async-container">
<div>Content</div>
</Teleport>
<!-- If this component loads asynchronously, defer won't work -->
<Suspense>
<AsyncComponent /> <!-- Contains #async-container -->
</Suspense>
</template>
Common Patterns
Recommended: Centralized Teleport Containers
<!-- index.html -->
<body>
<div id="app"></div>
<!-- Teleport destinations outside Vue app -->
<div id="modals" aria-live="polite"></div>
<div id="notifications" aria-live="assertive"></div>
<div id="tooltips"></div>
</body>