useSelectedLayoutSegment

Source URL: https://nextjs.org/docs/app/api-reference/functions/use-selected-layout-segment

useSelectedLayoutSegment

useSelectedLayoutSegment is a Client Component hook that lets you read the active route segment one level below the Layout it is called from.

It is useful for navigation UI, such as tabs inside a parent layout that change style depending on the active child segment.

'use client'

import { useSelectedLayoutSegment } from 'next/navigation'

export default function ExampleClientComponent() {
  const segment = useSelectedLayoutSegment()

  return <p>Active segment: {segment}</p>
}

'use client'

import { useSelectedLayoutSegment } from 'next/navigation'

export default function ExampleClientComponent() {
  const segment = useSelectedLayoutSegment()

  return <p>Active segment: {segment}</p>
}

Good to know:

• Since useSelectedLayoutSegment is a Client Component hook, and Layouts are Server Components by default, useSelectedLayoutSegment is usually called via a Client Component that is imported into a Layout.
• useSelectedLayoutSegment only returns the segment one level down. To return all active segments, see useSelectedLayoutSegments
• For catch-all routes, the matched segments are returned as a single joined string. For example, given app/blog/[...slug]/page.js, calling from app/blog/layout.js when visiting /blog/a/b/c returns 'a/b/c'.

Parameters

const segment = useSelectedLayoutSegment(parallelRoutesKey?: string)

useSelectedLayoutSegment optionally accepts a parallelRoutesKey, which allows you to read the active route segment within that slot.

Returns

useSelectedLayoutSegment returns a string of the active segment or null if one doesn’t exist.

For example, given the Layouts and URLs below, the returned segment would be:

Layout	Visited URL	Returned Segment
app/layout.js	/	null
app/layout.js	/dashboard	'dashboard'
app/dashboard/layout.js	/dashboard	null
app/dashboard/layout.js	/dashboard/settings	'settings'
app/dashboard/layout.js	/dashboard/analytics	'analytics'
app/dashboard/layout.js	/dashboard/analytics/monthly	'analytics'

For catch-all routes ([...slug]), the returned segment contains all matched path segments joined as a single string:

Layout	Visited URL	Returned Segment
app/blog/layout.js	/blog/a/b/c	'a/b/c'

Examples

Creating an active link component

You can use useSelectedLayoutSegment to create an active link component that changes style depending on the active segment. For example, a featured posts list in the sidebar of a blog:

'use client'

import Link from 'next/link'
import { useSelectedLayoutSegment } from 'next/navigation'

// This *client* component will be imported into a blog layout
export default function BlogNavLink({
  slug,
  children,
}: {
  slug: string
  children: React.ReactNode
}) {
  // Navigating to `/blog/hello-world` will return 'hello-world'
  // for the selected layout segment
  const segment = useSelectedLayoutSegment()
  const isActive = slug === segment

  return (
    <Link
      href={`/blog/${slug}`}
      // Change style depending on whether the link is active
      style={{ fontWeight: isActive ? 'bold' : 'normal' }}
    >
      {children}
    </Link>
  )
}

'use client'

import Link from 'next/link'
import { useSelectedLayoutSegment } from 'next/navigation'

// This *client* component will be imported into a blog layout
export default function BlogNavLink({ slug, children }) {
  // Navigating to `/blog/hello-world` will return 'hello-world'
  // for the selected layout segment
  const segment = useSelectedLayoutSegment()
  const isActive = slug === segment

  return (
    <Link
      href={`/blog/${slug}`}
      // Change style depending on whether the link is active
      style={{ fontWeight: isActive ? 'bold' : 'normal' }}
    >
      {children}
    </Link>
  )
}

// Import the Client Component into a parent Layout (Server Component)
import { BlogNavLink } from './blog-nav-link'
import getFeaturedPosts from './get-featured-posts'

export default async function Layout({
  children,
}: {
  children: React.ReactNode
}) {
  const featuredPosts = await getFeaturedPosts()
  return (
    <div>
      {featuredPosts.map((post) => (
        <div key={post.id}>
          <BlogNavLink slug={post.slug}>{post.title}</BlogNavLink>
        </div>
      ))}
      <div>{children}</div>
    </div>
  )
}

// Import the Client Component into a parent Layout (Server Component)
import { BlogNavLink } from './blog-nav-link'
import getFeaturedPosts from './get-featured-posts'

export default async function Layout({ children }) {
  const featuredPosts = await getFeaturedPosts()
  return (
    <div>
      {featuredPosts.map((post) => (
        <div key={post.id}>
          <BlogNavLink slug={post.slug}>{post.title}</BlogNavLink>
        </div>
      ))}
      <div>{children}</div>
    </div>
  )
}

Version History

Version	Changes
v13.0.0	useSelectedLayoutSegment introduced.

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