bsky-app/docs/localization.md

Internationalization

We want the official Bluesky app to be supported in as many languages as possible. If you want to help us translate the app, please open a PR or issue on the Bluesky app repo on GitHub

Tools

We are using Lingui to manage translations. You can find the documentation here.

Adding new strings

When adding a new string, do it as follows:

// Before
import { Text } from "react-native";

<Text>Hello World</Text>

// After
import { Text } from "react-native";
import { Trans } from "@lingui/macro";

<Text><Trans>Hello World</Trans></Text>

The <Trans> macro will extract the string and add it to the catalog. It is not really a component, but a macro. Further reading here

However sometimes you will run into this case:

// Before
import { Text } from "react-native";

const text = "Hello World";
<Text accessibilityLabel="Label is here">{text}</Text>

In this case, you cannot use the useLingui() hook:

import { msg } from "@lingui/macro";
import { useLingui } from "@lingui/react";

const { _ } = useLingui();
return <Text accessibilityLabel={_(msg`Label is here`)}>{text}</Text>

If you want to do this outside of a React component, you can use the t macro instead (note: this won't react to changes if the locale is switched dynamically within the app):

import { t } from "@lingui/macro";

const text = t`Hello World`;

We can then run yarn intl:extract to update the catalog in src/locale/locales/{locale}/messages.po. This will add the new string to the catalog. We can then run yarn intl:compile to update the translation files in src/locale/locales/{locale}/messages.js. This will add the new string to the translation files. The configuration for translations is defined in lingui.config.js

So the workflow is as follows:

1. Wrap messages in Trans macro
2. Run yarn intl:extract command to generate message catalogs
3. Translate message catalogs (send them to translators usually)
4. Run yarn intl:compile to create runtime catalogs
5. Load runtime catalog
6. Enjoy translated app!

Common pitfalls

These pitfalls are memoization pitfalls that will cause the components to not re-render when the locale is changed -- causing stale translations to be shown.

import { msg } from "@lingui/macro";
import { i18n } from "@lingui/core";

const welcomeMessage = msg`Welcome!`;

// ❌ Bad! This code won't work
export function Welcome() {
  const buggyWelcome = useMemo(() => {
    return i18n._(welcomeMessage);
  }, []);

  return <div>{buggyWelcome}</div>;
}

// ❌ Bad! This code won't work either because the reference to i18n does not change
export function Welcome() {
  const { i18n } = useLingui();

  const buggyWelcome = useMemo(() => {
    return i18n._(welcomeMessage);
  }, [i18n]);

  return <div>{buggyWelcome}</div>;
}

// ✅ Good! `useMemo` has i18n context in the dependency
export function Welcome() {
  const linguiCtx = useLingui();

  const welcome = useMemo(() => {
    return linguiCtx.i18n._(welcomeMessage);
  }, [linguiCtx]);

  return <div>{welcome}</div>;
}

// 🤩 Better! `useMemo` consumes the `_` function from the Lingui context
export function Welcome() {
  const { _ } = useLingui();

  const welcome = useMemo(() => {
    return _(welcomeMessage);
  }, [_]);

  return <div>{welcome}</div>;
}

Credits

Please check each individual messages.po file for the credits of the translators. We are very grateful for their help!

If you would like to translate the Bluesky app into your language, please open a PR or issue on this repo.