react-native-localize

What is react-native-localize?

The react-native-localize package provides localization utilities for React Native applications. It helps in handling various localization tasks such as determining the user's locale, timezone, and country, as well as formatting numbers, dates, and times according to the user's locale.

What are react-native-localize's main functionalities?

Get User's Locale

This feature allows you to get the list of locales preferred by the user. The code sample retrieves the user's preferred locales and logs them to the console.

const { getLocales } = require('react-native-localize');
const locales = getLocales();
console.log(locales);

Get User's Timezone

This feature allows you to get the user's current timezone. The code sample retrieves the user's timezone and logs it to the console.

const { getTimeZone } = require('react-native-localize');
const timeZone = getTimeZone();
console.log(timeZone);

Get User's Country

This feature allows you to get the user's current country. The code sample retrieves the user's country and logs it to the console.

const { getCountry } = require('react-native-localize');
const country = getCountry();
console.log(country);

Format Number

This feature allows you to get the number formatting settings for the user's locale. The code sample retrieves the decimal and grouping separators and logs them to the console.

const { getNumberFormatSettings } = require('react-native-localize');
const { decimalSeparator, groupingSeparator } = getNumberFormatSettings();
console.log(`Decimal Separator: ${decimalSeparator}, Grouping Separator: ${groupingSeparator}`);

Handle Localization Changes

This feature allows you to handle changes in localization settings. The code sample adds an event listener that logs a message when localization settings change.

const { addEventListener, removeEventListener } = require('react-native-localize');
const handleLocalizationChange = () => {
  console.log('Localization settings changed');
};
addEventListener('change', handleLocalizationChange);
// To remove the listener
// removeEventListener('change', handleLocalizationChange);

Other packages similar to react-native-localize

i18next

i18next is a popular internationalization framework for JavaScript that provides a complete solution for localizing your app. It supports multiple languages, pluralization, and interpolation. Compared to react-native-localize, i18next offers more comprehensive internationalization features but requires more setup.

react-intl

react-intl is a library for internationalizing React applications. It provides components and an API to format dates, numbers, and strings, and to handle pluralization. While react-intl focuses on formatting and message handling, react-native-localize provides more utilities for determining the user's locale and timezone.

expo-localization

expo-localization is a package from the Expo ecosystem that provides localization utilities similar to react-native-localize. It can determine the user's locale, timezone, and country. However, expo-localization is designed to work seamlessly with Expo projects, whereas react-native-localize can be used in any React Native project.

README

🌍  react-native-localize

A toolbox for your React Native app localization.

Support

package name	version	react-native version
react-native-localize	2.0.0+	0.60.0+
react-native-localize	1.0.0+	0.56.0+

Setup

$ npm install --save react-native-localize
# --- or ---
$ yarn add react-native-localize

Don't forget to run pod install after that !

🆘  Manual linking

Because this package targets React Native 0.60.0+, you will probably don't need to link it manually. Otherwise if it's not the case, follow this additional instructions:

👀 See manual linking instructions

iOS

Add this line to your ios/Podfile file, then run pod install.

target 'YourAwesomeProject' do
  # …
  pod 'RNLocalize', :path => '../node_modules/react-native-localize'
end

Android

1. Add the following lines to android/settings.gradle:

include ':react-native-localize'
project(':react-native-localize').projectDir = new File(rootProject.projectDir, '../node_modules/react-native-localize/android')

1. Add the implementation line to the dependencies in android/app/build.gradle:

dependencies {
  // ...
  implementation project(':react-native-localize')
}

1. Add the import and link the package in MainApplication.java:

import com.zoontek.rnlocalize.RNLocalizePackage; // <- add the RNLocalizePackage import

public class MainApplication extends Application implements ReactApplication {

  // …

  @Override
  protected List<ReactPackage> getPackages() {
    @SuppressWarnings("UnnecessaryLocalVariable")
    List<ReactPackage> packages = new PackageList(this).getPackages();
    // …
    packages.add(new RNLocalizePackage());
    return packages;
  }

  // …
}

Web support

This package supports react-native-web. Follow their official guide to configure webpack.

Basic usage example

import * as RNLocalize from "react-native-localize";

console.log(RNLocalize.getLocales());
console.log(RNLocalize.getCurrencies());

RNLocalize.addEventListener("change", () => {
  // do localization related stuff…
});

API

getLocales()

Returns the user preferred locales, in order.

Method type

type getLocales = () => Array<{
  languageCode: string;
  scriptCode?: string;
  countryCode: string;
  languageTag: string;
  isRTL: boolean;
}>;

Usage example

console.log(RNLocalize.getLocales());
/* -> [
  { countryCode: "GB", languageTag: "en-GB", languageCode: "en", isRTL: false },
  { countryCode: "US", languageTag: "en-US", languageCode: "en", isRTL: false },
  { countryCode: "FR", languageTag: "fr-FR", languageCode: "fr", isRTL: false },
] */

---

getNumberFormatSettings()

Returns number formatting settings.

Method type

type getNumberFormatSettings = () => {
  decimalSeparator: string;
  groupingSeparator: string;
};

Usage example

console.log(RNLocalize.getNumberFormatSettings());
/* -> {
  decimalSeparator: ".",
  groupingSeparator: ",",
} */

---

getCurrencies()

Returns the user preferred currency codes, in order.

Method type

type getCurrencies = () => Array<string>;

Usage example

console.log(RNLocalize.getCurrencies());
// -> ["EUR", "GBP", "USD"]

---

getCountry()

Returns the user current country code (based on its device locale, not on its position).

Method type

type getCountry = () => string;

Usage example

console.log(RNLocalize.getCountry());
// -> "FR"

---

getCalendar()

Returns the user preferred calendar format.

Method type

type getCalendar = () => "gregorian" | "japanese" | "buddhist";

Usage example

console.log(RNLocalize.getCalendar());
// -> "gregorian"

---

getTemperatureUnit()

Returns the user preferred temperature unit.

Method type

type getTemperatureUnit = () => "celsius" | "fahrenheit";

Usage example

console.log(RNLocalize.getTemperatureUnit());
// -> "celsius"

---

getTimeZone()

Returns the user preferred timezone (based on its device settings, not on its position).

Method type

type getTimeZone = () => string;

Usage example

console.log(RNLocalize.getTimeZone());
// -> "Europe/Paris"

---

uses24HourClock()

Returns true if the user prefers 24h clock format, false if he prefers 12h clock format.

Method type

type uses24HourClock = () => boolean;

Usage example

console.log(RNLocalize.uses24HourClock());
// -> true

---

usesMetricSystem()

Returns true if the user prefers metric measure system, false if he prefers imperial.

Method type

type usesMetricSystem = () => boolean;

Usage example

console.log(RNLocalize.usesMetricSystem());
// -> true

---

usesAutoDateAndTime()

Tells if the automatic date & time setting is enabled on the phone. Android only

Method type

type Option<T> = T | undefined;
type usesAutoDateAndTime = () => Option<boolean>;

Usage example

console.log(RNLocalize.usesAutoDateAndTime()); // true or false

---

usesAutoTimeZone()

Tells if the automatic time zone setting is enabled on the phone. Android only

Method type

type Option<T> = T | undefined;
type usesAutoTimeZone = () => Option<boolean>;

Usage example

console.log(RNLocalize.usesAutoTimeZone());

---

addEventListener() / removeEventListener()

Allows you to listen for any localization change.

Methods type

type addEventListener = (type: "change", handler: Function) => void;
type removeEventListener = (type: "change", handler: Function) => void;

Usage example

function handleLocalizationChange() {
  console.log(RNLocalize.getLocales());
}

RNLocalize.addEventListener("change", handleLocalizationChange);
// …later (ex: component unmount)
RNLocalize.removeEventListener("change", handleLocalizationChange);

---

findBestAvailableLanguage()

Returns the best language tag possible and its reading direction (⚠️ it respects the user preferred languages list order, see explanations). Useful to pick the best translation available.

Method type

type findBestAvailableLanguage = (
  languageTags: Array<string>,
) => { languageTag: string; isRTL: boolean } | void;

Usage example

console.log(RNLocalize.findBestAvailableLanguage(["en-US", "en", "fr"]));
// -> { languageTag: "en-US", isRTL: false }

Examples with i18n-js

Browse the files in the /example directory.

How to test your code

Because it's a native module, you might need to mock this package to run your tests flawlessly.
Here is an example for Jest, adapt it to your needs :

// __mocks__/react-native-localize.js

const getLocales = () => [
  // you can choose / add the locales you want
  { countryCode: "US", languageTag: "en-US", languageCode: "en", isRTL: false },
  { countryCode: "FR", languageTag: "fr-FR", languageCode: "fr", isRTL: false },
];

// use a provided translation, or return undefined to test your fallback
const findBestAvailableLanguage = () => ({
  languageTag: "en-US",
  isRTL: false,
});

const getNumberFormatSettings = () => ({
  decimalSeparator: ".",
  groupingSeparator: ",",
});

const getCalendar = () => "gregorian"; // or "japanese", "buddhist"
const getCountry = () => "US"; // the country code you want
const getCurrencies = () => ["USD", "EUR"]; // can be empty array
const getTemperatureUnit = () => "celsius"; // or "fahrenheit"
const getTimeZone = () => "Europe/Paris"; // the timezone you want
const uses24HourClock = () => true;
const usesMetricSystem = () => true;

const addEventListener = jest.fn();
const removeEventListener = jest.fn();

export {
  findBestAvailableLanguage,
  getLocales,
  getNumberFormatSettings,
  getCalendar,
  getCountry,
  getCurrencies,
  getTemperatureUnit,
  getTimeZone,
  uses24HourClock,
  usesMetricSystem,
  addEventListener,
  removeEventListener,
};

Add project's supported localizations (iOS)