GenerateMetadata for dynamic metadata in NextJS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a dynamic metadata function in Next.js.

NextJS

export async function generateMetadata({ params }) {
  return {
    title: [1]
  };
}

Drag options to blanks, or click blank then click option'

Aparams.id

B'Static Title'

C`User Profile: ${params.id}`

Dnull

Attempts:

3 left

💡 Hint

Common Mistakes

Using single quotes instead of backticks for template literals.

Returning a static string instead of dynamic metadata.

The generateMetadata function returns an object with a dynamic title using template literals and params.id.

2fill in blank

medium

Complete the code to import the correct type for generateMetadata in Next.js.

NextJS

import type { [1] } from 'next';

Drag options to blanks, or click blank then click option'

AGenerateMetadataFunction

BGenerateMetadata

CMetadataFunction

DMetadata

Attempts:

3 left

💡 Hint

Common Mistakes

Importing a non-existent type like 'GenerateMetadataFunction'.

Confusing the type with 'GenerateMetadata'.

The correct type to import for the generateMetadata function is Metadata from Next.js.

3fill in blank

hard

Fix the error in the code to correctly return dynamic metadata with async function.

NextJS

export async function generateMetadata({ params }) {
  const title = 'Profile of ' + [1];
  return {
    title
  };
}

Drag options to blanks, or click blank then click option'

Aparams.id

Bparams.slug

Cparams.name

Dparams.userId

Attempts:

3 left

💡 Hint

Common Mistakes

Using a wrong parameter name like userId or slug.

Forgetting to concatenate the parameter to the string.

The dynamic parameter is accessed as params.id to build the title string.

4fill in blank

hard

Fill both blanks to create a metadata object with dynamic title and description.

NextJS

export async function generateMetadata({ params }) {
  return {
    title: [1],
    description: [2]
  };
}

Drag options to blanks, or click blank then click option'

A`Post: ${params.slug}`

B`This is the post about ${params.slug}`

C'Static description'

D'Static title'

Attempts:

3 left

💡 Hint

Common Mistakes

Using static strings instead of dynamic template literals.

Mixing up title and description values.

The title and description use template literals with params.slug for dynamic metadata.

5fill in blank

hard

Fill all three blanks to generate metadata with dynamic title, description, and openGraph title.

NextJS

export async function generateMetadata({ params }) {
  return {
    title: [1],
    description: [2],
    openGraph: {
      title: [3]
    }
  };
}

Drag options to blanks, or click blank then click option'

A`Article: ${params.slug}`

B`Detailed info about ${params.slug}`

D'Static OpenGraph Title'

Attempts:

3 left

💡 Hint

Common Mistakes

Using static strings for openGraph title.

Not using template literals consistently.

The title and openGraph.title share the same dynamic template literal, while description is a different dynamic string.

Practice

1. What is the main purpose of the generateMetadata function in Next.js?

easy

A. To fetch data on the client after page load

B. To handle client-side routing between pages

C. To create dynamic page titles and descriptions before rendering

D. To style components dynamically using CSS

Solution

1. Step 1: Understand the role of generateMetadata

   This function runs on the server before the page renders to set metadata dynamically.

2. Step 2: Identify its main use

   It is used to create dynamic page titles and descriptions for SEO and relevant info.

3. Final Answer:

   To create dynamic page titles and descriptions before rendering -> Option C

4. Quick Check:

   Dynamic metadata = To create dynamic page titles and descriptions before rendering [OK]

Hint: Remember: generateMetadata sets SEO info before page loads [OK]

Common Mistakes:

• Confusing generateMetadata with client-side data fetching
• Thinking it handles routing or styling
• Assuming it runs on the client

2. Which of the following is the correct syntax to export a generateMetadata function in a Next.js page?

easy

A. export const generateMetadata = () => { document.title = 'Page' }

B. export async function generateMetadata() { return { title: 'Page' } }

C. function generateMetadata() { console.log('metadata') } export generateMetadata

D. export default function generateMetadata() { return Page }

Solution

1. Step 1: Recall correct export syntax

   Next.js expects generateMetadata as an exported async function returning an object with metadata.

2. Step 2: Check each option

   export async function generateMetadata() { return { title: 'Page' } } correctly exports an async function returning an object with a title property.

3. Final Answer:

   export async function generateMetadata() { return { title: 'Page' } } -> Option B

4. Quick Check:

   Correct export syntax = export async function generateMetadata() { return { title: 'Page' } } [OK]

Hint: Use async function returning object for generateMetadata [OK]

Common Mistakes:

• Using default export instead of named export
• Returning JSX instead of an object
• Trying to set document.title inside generateMetadata

3. Given this generateMetadata function, what will be the page title?

export async function generateMetadata({ params }) {
  return { title: `User: ${params.username}` };
}

And the URL is /user/jane.

medium

A. User: jane

B. User: params.username

C. User: undefined

D. User: /user/jane

Solution

1. Step 1: Understand parameter usage

   The function receives params with username from the URL segment.

2. Step 2: Substitute params.username with actual value

   Since URL is /user/jane, params.username is 'jane', so title becomes 'User: jane'.

3. Final Answer:

   User: jane -> Option A

4. Quick Check:

   Dynamic title uses params.username = User: jane [OK]

Hint: URL params fill template strings in generateMetadata [OK]

Common Mistakes:

• Using literal string 'params.username' instead of value
• Assuming params is undefined without route setup
• Confusing URL path with metadata title

4. What is wrong with this generateMetadata function?

export function generateMetadata() {
  return { title: 'Home' }
  console.log('Metadata generated')
}

medium

A. generateMetadata cannot be a named export

B. The function must be async to work

C. The return value must be a string, not an object

D. The console.log runs after return and is unreachable

Solution

1. Step 1: Analyze function flow

   The return statement ends the function immediately, so code after it won't run.

2. Step 2: Identify unreachable code

   The console.log after return is unreachable and will never execute.

3. Final Answer:

   The console.log runs after return and is unreachable -> Option D

4. Quick Check:

   Code after return is unreachable = The console.log runs after return and is unreachable [OK]

Hint: Code after return is ignored, place logs before return [OK]

Common Mistakes:

• Thinking function must be async always
• Expecting return to accept strings only
• Confusing export types

5. You want to create dynamic metadata for a blog post page that shows the post title and author. Which generateMetadata implementation correctly handles this using params and fetch to get post data asynchronously?

hard

A. export async function generateMetadata({ params }) {
const post = await fetch(`/api/posts/${params.id}`).then(res => res.json());
return { title: post.title, description: `By ${post.author}` };
}

B. export function generateMetadata({ params }) {
const post = fetch(`/api/posts/${params.id}`).then(res => res.json());
return { title: post.title, description: `By ${post.author}` };
}

C. export async function generateMetadata() {
const post = await fetch('/api/posts').then(res => res.json());
return { title: post.title, description: post.author };
}

D. export async function generateMetadata({ params }) {
return { title: params.title, description: params.author };
}

Solution

1. Step 1: Identify async data fetching

   To get post data dynamically, generateMetadata must be async and await the fetch call.

2. Step 2: Check usage of params and fetch

   export async function generateMetadata({ params }) { const post = await fetch(`/api/posts/${params.id}`).then(res => res.json()); return { title: post.title, description: `By ${post.author}` }; } correctly awaits fetch with params.id and returns metadata using fetched data.

3. Final Answer:

   export async function generateMetadata({ params }) { const post = await fetch(`/api/posts/${params.id}`).then(res => res.json()); return { title: post.title, description: `By ${post.author}` }; } -> Option A

4. Quick Check:

   Async fetch with params used correctly = export async function generateMetadata({ params }) { const post = await fetch(`/api/posts/${params.id}`).then(res => res.json()); return { title: post.title, description: `By ${post.author}` }; } [OK]

Hint: Use async/await with params to fetch dynamic metadata [OK]

Common Mistakes:

• Not awaiting fetch causing unresolved promises
• Ignoring params and fetching all posts
• Returning params directly without fetching data