Nuxt

Path-based routing

Rather than a regular Vue.js application, which ordinarily requires every route to be manually registered, Nuxt uses path-based routing to automatically register every route in an application.^[9]

Pages are declared in the pages/ folder, where the name of the page file becomes the name of the route. Dynamic parameters can be added using square brackets, and catch-all routes can be added using three dots and square brackets, much like JavaScript's array spread syntax.^[10]

• /pages/about.vue - Matches /about.
• /pages/user/[id].vue - Matches all routes directly under /user.
• /pages/posts/[...slug].vue - Matches all routes under /posts.
• /pages/admin/[[page]].vue - Matches /admin in addition to all routes directly under it.

Automatic imports

Nuxt automatically imports most Vue composition API functions, and any helper functions from the composables/ and utils/ folders.^[11]

<script setup>
    // ref is automatically imported
    const count = ref(0);
    // useRoute is also automatically imported
    const route = useRoute();
</script>

<template>
    <span>{{ count }}</span>
</template>

Layouts

Nuxt supports SSR-friendly layouts out of the box, which allows similar pages to use the same basic templates, such as a header and footer. Layouts are declared in the layouts/ folder, and work using native Vue slots.

To enable layouts in a Nuxt project, the entry point of the application, app.vue, must include a NuxtLayout component to toggle between layouts for each page.^[12]

<!-- sample app.vue file content -->
<template>
    <NuxtLayout>
        <NuxtPage />
    </NuxtLayout>
</template>

The default layout is located at layouts/default.vue, and must include a slot for the page content.

<!-- sample layout file content -->
<template>
    <CustomNavbar />
    <slot />
    <CustomFooter />
</template>

A page can use a custom layout by using the definePageMeta helper in a setup function or block.^[13]

<script setup>
definePageMeta({
    layout: "custom",
});
</script>

<template>
    <!-- this will now fill the slot of the custom layout -->
</template>

Middleware

Nuxt adds middleware support to applications, which enables server logic to run between navigation changes. Both global and page-specific middleware files are supported.^[14]

Middleware is declared in the middleware/ folder, which exports a function that takes in the current and previous routes as parameters. From there, globally-available helpers like abortNavigation and navigateTo can be used to control navigation.^[15][16]

export default defineNuxtMiddleware((to, from) => {
    // navigation logic
    if (to.params.id === "0")
        return abortNavigation();
    return navigateTo(`/users/${to.params.id}`);
});

Server API

Nuxt can also generate server API routes and handlers, using the server/ folder. Any file placed in server/api will become an API route, and any file placed in server/routes will become a route file, the difference being the final file location (server/api adds an api prefix to the path).^[17]

// server/api/hello.ts
export default defineEventHandler((event) => {
    return {
        some: "data here",
    };
});

This can now be called from components using the useFetch composable.

<script setup>
const { data } = await useFetch('/api/hello')
</script>

<template>
  <pre>{{ data }}</pre>
</template>