Next-intl library integration in NextJS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the NextIntlProvider component from the next-intl library.

NextJS

import { [1] } from 'next-intl';

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

AIntlProvider

BNextIntlProvider

CNextProvider

DIntlNextProvider

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'IntlProvider' instead of 'NextIntlProvider'.

Misspelling the component name.

The NextIntlProvider component is imported from 'next-intl' to provide internationalization support in Next.js apps.

2fill in blank

medium

Complete the code to load locale messages asynchronously in a Next.js page.

NextJS

export async function getStaticProps({ params }) {
  const messages = await import(`../messages/$[1].json`);
  return { props: { messages: messages.default } };
}

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

Aregion

Blang

Clanguage

Dlocale

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'lang' or 'language' which are not the parameter names in Next.js routing.

Forgetting to access the default export of the JSON.

The 'locale' parameter contains the current locale string, used to load the correct messages file.

3fill in blank

hard

Fix the error in the NextIntlProvider usage by completing the missing prop.

NextJS

<NextIntlProvider locale={locale} messages={messages} [1]>
  <Component {...pageProps} />
</NextIntlProvider>

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

AfallbackLocale

BdefaultLocale

CdefaultMessages

DfallbackMessages

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'defaultLocale' which is not a prop for NextIntlProvider.

Confusing fallback messages with fallback locale.

The 'fallbackLocale' prop specifies which locale to use if the current locale messages are missing.

4fill in blank

hard

Fill both blanks to create a translation hook and use it to translate a key.

NextJS

import { useTranslations } from 'next-intl';

export default function Greeting() {
  const t = [1]();
  return <p>{t([2])}</p>;
}

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

AuseTranslations

B'greeting.hello'

C'hello'

DuseTranslation

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'useTranslation' which is not from next-intl.

Passing incorrect or incomplete keys to the translation function.

The hook 'useTranslations' returns a function 't' to translate keys like 'greeting.hello'.

5fill in blank

hard

Fill all three blanks to define a messages object, load it, and pass it to NextIntlProvider.

NextJS

const messages = [1];

export async function getStaticProps() {
  return { props: { messages: [2] } };
}

export default function App({ Component, pageProps }) {
  return (
    <NextIntlProvider locale="en" messages=[3]>
      <Component {...pageProps} />
    </NextIntlProvider>
  );
}

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

A{ greeting: 'Hello' }

Bmessages

CpageProps.messages

DpageProps

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the whole pageProps instead of pageProps.messages to NextIntlProvider.

Not defining messages as an object.

We define a messages object, return it in getStaticProps, and pass pageProps.messages to NextIntlProvider.

Practice

1. What is the main purpose of the NextIntlProvider component in a Next.js app using next-intl?

easy

A. To fetch data from an API

B. To provide translation messages and locale context to the app

C. To handle routing between pages

D. To style components with CSS

Solution

1. Step 1: Understand the role of NextIntlProvider

   The NextIntlProvider wraps the app and supplies translation messages and locale information to all child components.

2. Step 2: Compare with other options

   Fetching data, routing, and styling are unrelated to NextIntlProvider's purpose.

3. Final Answer:

   To provide translation messages and locale context to the app -> Option B

4. Quick Check:

   NextIntlProvider = translation context provider [OK]

Hint: NextIntlProvider always wraps your app to share translations [OK]

Common Mistakes:

• Confusing NextIntlProvider with data fetching
• Thinking it handles routing or styling
• Not realizing it shares locale and messages

2. Which of the following is the correct way to import and use the useTranslations hook in a Next.js component?

easy

A. import { useTranslations } from 'next-intl'; const t = useTranslations('common');

B. import useTranslations from 'next-intl'; const t = useTranslations('common');

C. import { useTranslations } from 'next-intl'; const t = useTranslations();

D. import { useTranslation } from 'next-intl'; const t = useTranslation('common');

Solution

1. Step 1: Check correct import syntax

   The hook is named useTranslations and imported with curly braces from 'next-intl'.

2. Step 2: Verify usage with namespace

   It requires a namespace string like 'common' to get translations from that section.

3. Final Answer:

   import { useTranslations } from 'next-intl'; const t = useTranslations('common'); -> Option A

4. Quick Check:

   Correct import and call with namespace = import { useTranslations } from 'next-intl'; const t = useTranslations('common'); [OK]

Hint: Always import with braces and pass namespace string [OK]

Common Mistakes:

• Importing without braces
• Calling useTranslations without arguments
• Using wrong hook name useTranslation

3. Given this component using next-intl:

import { useTranslations } from 'next-intl';

export default function Greeting() {
  const t = useTranslations('greeting');
  return <h1>{t('hello')}</h1>;
}

If the messages for locale 'en' are { greeting: { hello: 'Hello, friend!' } }, what will be rendered?

medium

A. An error because 'hello' key is missing

B. <h1>greeting.hello</h1>

C. <h1>Hello, friend!</h1>

D. <h1>Hello</h1>

Solution

1. Step 1: Understand useTranslations usage

   The hook useTranslations('greeting') accesses the 'greeting' namespace in messages.

2. Step 2: Check message key 'hello'

   The key 'hello' inside 'greeting' is 'Hello, friend!'. So t('hello') returns that string.

3. Final Answer:

   <h1>Hello, friend!</h1> -> Option C

4. Quick Check:

   Namespace + key returns correct text = <h1>Hello, friend!</h1> [OK]

Hint: Namespace + key in messages gives displayed text [OK]

Common Mistakes:

• Expecting raw keys instead of translated text
• Assuming missing keys cause errors
• Confusing namespace with key

4. You wrote this code in a Next.js page:

import { NextIntlProvider } from 'next-intl';

export default function Page({ messages }) {
  return (
    <NextIntlProvider messages={messages} locale="en">
      <h1>Welcome</h1>
    </NextIntlProvider>
  );
}

But you get an error: "messages is undefined". What is the likely cause?

medium

A. You forgot to load and pass messages as a prop to the Page component

B. NextIntlProvider does not accept a messages prop

C. Locale must be passed as a number, not a string

D. You must import useTranslations instead of NextIntlProvider

Solution

1. Step 1: Check messages prop usage

   The NextIntlProvider requires a valid messages object passed as a prop.

2. Step 2: Identify cause of undefined

   If messages is undefined, it means the parent or data loader did not supply it properly.

3. Final Answer:

   You forgot to load and pass messages as a prop to the Page component -> Option A

4. Quick Check:

   Missing messages prop causes undefined error [OK]

Hint: Always load and pass messages before using NextIntlProvider [OK]

Common Mistakes:

• Thinking NextIntlProvider doesn't need messages
• Passing locale as number instead of string
• Confusing hooks with provider component

5. You want to support English and Spanish in your Next.js app using next-intl. You have message files:

locales/en.json
locales/es.json

How should you structure your app/layout.tsx to load messages dynamically and provide translations to all pages?

hard

A. Load messages inside each page component instead of layout

B. Import both JSON files statically and pass both to NextIntlProvider at once

C. Use useTranslations in layout to load messages and pass to children

D. Use async function to load messages based on locale, then wrap children with NextIntlProvider passing loaded messages and locale

Solution

1. Step 1: Understand dynamic message loading

   To support multiple locales, load messages dynamically based on the current locale in an async layout or provider.

2. Step 2: Wrap app with NextIntlProvider

   Pass the loaded messages and locale to NextIntlProvider wrapping all children so translations are available app-wide.

3. Final Answer:

   Use async function to load messages based on locale, then wrap children with NextIntlProvider passing loaded messages and locale -> Option D

4. Quick Check:

   Dynamic loading + provider wrapping = Use async function to load messages based on locale, then wrap children with NextIntlProvider passing loaded messages and locale [OK]

Hint: Load messages async by locale, wrap app with NextIntlProvider [OK]

Common Mistakes:

• Importing all locales at once statically
• Loading messages inside pages instead of layout
• Using useTranslations to load messages