Storybook next-intl addon

Easy next-intl Storybook integration.

Required Peer Dependencies:

• storybook - ^8.2.0
• next-intl - ^3.0.0

This Storybook addon assumes your project is already set up with next-intl, and that it is properly configured and working.

Installation

Install this addon as a devDependency.

npm i -D storybook-next-intl

Usage

After installing, follow these 3 steps to enable this addon in Storybook.

main.ts

Insert this addon into your addons array:

{
  addons: [
    // other addons...
    'storybook-next-intl',
  ]
}

---

next-intl.ts

Create a file in your .storybook folder called next-intl.ts (or whatever you like).

In this file, copy and paste the below code and make whatever modifications you need (paths to messages files, etc.).

import en from '../src/messages/en.json';
import fr from '../src/messages/fr.json';
import ja from '../src/messages/ja.json';

const messagesByLocale: Record<string, any> = {en, fr, ja};

const nextIntl = {
  defaultLocale: 'en',
  messagesByLocale,
};

export default nextIntl;

You can also include options such as formats, defaultTranslationValues, onError and getMessageFallback.

const nextIntl = {
  defaultLocale: 'en',
  messagesByLocale,
  formats: {/* your settings */},
  defaultTranslationValues: {/* your settings */},
  onError: (error) => console.error(error),
  getMessageFallback: ({namespace, key}) => `${namespace}.${key}`,
};

---

preview.ts

In your preview.ts, you need to add the locales and locale to initialGlobals, as well as adding nextIntl that you exported from the above file to parameters.

locales is an object where the keys are the "ids" of the locales/languages and the values are the names you want to display in the dropdown.

locale is what you want the default locale to be.

import nextIntl from './next-intl';

const preview: Preview = {
    initialGlobals: {
        locale: 'en',
        locales: {
            en: 'English',
            fr: 'Français',
            ja: '日本語',
        },
    },
    parameters: {
      nextIntl,
    },
};

export default preview;

You can also use full locale strings as keys. It depends on your next-intl configuration.

import nextIntl from './next-intl';

const preview: Preview = {
    initialGlobals: {
        locale: 'en_US',
        locales: {
            en_US: 'English (US)',
            en_GB: 'English (GB)',
            fr_FR: 'Français',
            ja_JP: '日本語',
        },
    },
    parameters: {
      nextIntl,
    },
};

export default preview;

The locales object can also have values as an object with keys of title, left, or right.

This is useful if you want to include an emoji flag or some other string to the left or right side.

For example:

import nextIntl from './next-intl';

const preview: Preview = {
    initialGlobals: {
        locale: "en",
        locales: {
            en: {icon: '🇺🇸', title: 'English', right: 'EN'},
            fr: {icon: '🇫🇷', title: 'Français', right: 'FR'},
            ja: {icon: '🇯🇵', title: '日本語', right: 'JA'},
        },
    },
    parameters: {
      nextIntl,
    },
};

export default preview;

Or something like this:

import nextIntl from './next-intl';

const preview: Preview = {
    initialGlobals: {
        locale: 'en_US',
        locales: {
            en_US: {title: 'English', right: 'US'},
            en_GB: {title: 'English', right: 'GB'},
            fr_FR: {title: 'Français', right: 'FR'},
            ja_JP: {title: '日本語', right: 'JA'},
        },
    },
    parameters: {
      nextIntl,
    },
};

export default preview;

Story Parameters Locale

If you want to have a story use a specific locale, set it in that Story's parameters.

export const Default: StoryObj = {
    render: () => <YourComponent/>,
};

export const Japanese: StoryObj = {
    parameters: {
        locale: 'ja',
    },
    render: () => <YourComponent/>,
};

Note that doing this switches the current locale to the parameter one, so when you change to a story without a parameter, it will stay at the last selected locale.

In the above example, if you view the Japanese story and then click back on the Default story, the locale will stay ja.

---

Once you have finished these steps and launch storybook, you should see a globe icon in the toolbar.

Clicking this globe icon will show a dropdown with the locales you defined in parameters.

Switching locales will use the strings defined in your locale json files.