usePreviewMode
Use usePreviewMode to check and control preview mode in Nuxt
usePreviewMode
Preview mode allows you to see how your changes would be displayed on a live site without revealing them to users.
You can use the built-in usePreviewMode
composable to access and control preview state in Nuxt. If the composable detects preview mode it will automatically force any updates necessary for useAsyncData
and useFetch
to rerender preview content.
const { enabled, state } = usePreviewMode()
Options
Custom enable
check
You can specify a custom way to enable preview mode. By default the usePreviewMode
composable will enable preview mode if there is a preview
param in url that is equal to true
(for example, http://localhost:3000?preview=true
). You can wrap the usePreviewMode
into custom composable, to keep options consistent across usages and prevent any errors.
export function useMyPreviewMode () {
return usePreviewMode({
shouldEnable: () => {
return !!route.query.customPreview
}
});
}
Modify default state
usePreviewMode
will try to store the value of a token
param from url in state. You can modify this state and it will be available for all usePreviewMode
calls.
const data1 = ref('data1')
const { enabled, state } = usePreviewMode({
getState: (currentState) => {
return { data1, data2: 'data2' }
}
})
getState
function will append returned values to current state, so be careful not to accidentally overwrite important state.Example
The example below creates a page where part of a content is rendered only in preview mode.
<script setup>
const { enabled, state } = usePreviewMode()
const { data } = await useFetch('/api/preview', {
query: {
apiKey: state.token
}
})
</script>
<template>
<div>
Some base content
<p v-if="enabled">
Only preview content: {{ state.token }}
<br>
<button @click="enabled = false">
disable preview mode
</button>
</p>
</div>
</template>
Now you can generate your site and serve it:
npx nuxi generate
npx nuxi preview
Then you can see your preview page by adding the query param preview
to the end of the page you want to see once:
?preview=true
usePreviewMode
should be tested locally with nuxi generate
and then nuxi preview
rather than nuxi dev
. (The preview command is not related to preview mode.)