storybook-i18next/README.md

Add i18next support to Storybook

# Storybook i18next addon (React)

Add i18next support to Storybook for React projects.

## Installation

This addon should be added as a dev dependency.

```bash
npm i -D storybook-i18next
```

```bash
yarn add -D storybook-i18next
```

You will need to install `i18next` and `react-i18next` as dependencies to your project if they are not already installed.
```bash
npm i -S i18next react-i18next
```

```bash
yarn add i18next react-i18next
```

## Usage

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

### main.js
Insert this addon into your addons array:
```javascript
{
  addons: [
    // other addons...
    'storybook-i18next',
  ]
}
```
---

### i18next.js
Create a file in your `.storybook` folder called `i18next.js` (or whatever you like).

In this file, copy and paste the below code and make whatever modifications you need.
```javascript
import {initReactI18next} from 'react-i18next';
import i18n from 'i18next';
import LanguageDetector from 'i18next-browser-languagedetector';

const ns = ['common'];
const supportedLngs = ['en', 'fr', 'ja'];

i18n.use(LanguageDetector)
  .use(initReactI18next)
  .init({
    //debug: true,
    lng: 'en',
    fallbackLng: 'en',
    interpolation: {
      escapeValue: false,
    },
    defaultNS: 'common',
    ns,
    supportedLngs,
  });

supportedLngs.forEach((lang) => {
  ns.forEach((n) => {
    i18n.addResources(
      lang,
      n,
      require(`../public/locales/${lang}/${n}.json`)
    );
  });
});

export {i18n};
```

Refer to the [i18next Configuration Options](https://www.i18next.com/overview/configuration-options) documentation for detailed information about the configuration options.


---

### preview.js
In your `preview.js`, you need to add the `locales` and `locale` parameters, as well as the `i18n` that you exported from the above file.

`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.

```javascript
import {i18n} from './i18next.js';

export const parameters = {
  i18n,
  locale: 'en',
  locales: {
    en: 'English',
    fr: 'Français',
    ja: '日本語',
  },
};
```

You can also use full locale strings as keys. It depends on your i18next configuration.

```javascript
import {i18n} from './i18next.js';

export const parameters = {
  i18n,
  locale: 'en_US',
  locales: {
    en_US: 'English (US)',
    en_GB: 'English (GB)',
    fr_FR: 'French',
    ja_JP: 'Japanese',
  },
};
```
---
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.