How to setup React i18next and Storybook
Most developers use i18next, a popular JavaScript library that lets apps define separate files for each supported locale. It detects a user’s language preferences and region, and only loads the detected locale.
Instead of being passed to components as inputs, the locale is shared globally through context. Let’s use i18next to extend Storybook with a locale switcher in the toolbar to choose which locale is shared with your components.
Follow along using the code examples in the react-i18next GitHub repository.
Prerequisites
Before we begin, ensure that you have a working React app using react-i18next which is set up with Storybook 6.0 or newer. If you need resources to set these up, I’ve included some recommendations below:
Or if you'd prefer a video, check out Chantastic's awesome video on adding i18next to your React app.
1. Expose i18next to Storybook
To make your translations available in your stories, you’ll first need to expose your i18next instance to Storybook. Here’s an example of an i18next instance from the ./src/i18n.js file being used in my React app.
To expose this instance to Storybook, we can import it into the ./.storybook/preview.js file where Storybook holds its shared story configurations.
2. Wrap your stories with the i18next provider
Now that Storybook has access to i18next, we need to share that with our stories. To do that we’re going to make a decorator to wrap our stories in.
Sweet! Our stories officially have access to our translations. If we change the lng defined in ./src/i18n.js you’ll see your stories reload in the new language.
3. Add a locale switcher
Hardcoding your locale is annoying and won’t be helpful to anyone viewing your deployed Storybook, so let’s add a locale switcher to the Storybook toolbar. If you want to learn more about switchers, check out Yann Braga’s article on adding a theme switcher.
To do this, we can declare a global variable named locale in .storybook/preview.js and assign it to a list of supported languages to choose from.
Looking back at Storybook, we can now see that we have a “Locale” switcher added to the toolbar with the options we just set.
Now let’s update our decorator to change our locale when we select a new language.
Voila— a fully functioning locale switcher for your stories powered by react-i18next!
4. Set document direction
Some languages are not read from left to right like English is. Arabic, for example, is read from right to left. HTML has built-in support for this with the dir attribute.
First of all, let's add Arabic as an option in our locale switcher by adding an object into the items array of our globalTypes.
Using i18next’s dir(lng) function and languageChanged event, we can set the document direction for the selected locale.
Now when we set our storybook to Arabic, the document direction gets set to ”rtl” 🎉
