Language

First please your json language in folder following your list language ./app/lang/.. . All language files are formatted with json data

Then please check file ./app/config/setting.js and define your list language support

/**
 * Basic Setting Variables Define
 */
export const BaseSetting = {
  defaultLanguage: 'en', // default language
  languageSupport: [
    'en',
    'vi',
    'ar',
    'da',
    'de',
    'el',
    'fr',
    'he',
    'id',
    'ja',
    'ko',
    'lo',
    'nl',
    'zh',
    'fa',
    'km',
  ]
}

RTL Layout

You can define then language code will apply RTL layout from file  ./app/utils/index.js

export const languageFromCode = code => {
  switch (code) {
    case 'en':
      return 'English';
    case 'vi':
      return 'Vietnamese';
    case 'ar':
      return 'Arabic';
    case 'da':
      return 'Danish';
    case 'de':
      return 'German';
    case 'el':
      return 'Greek';
    case 'fr':
      return 'French';
    case 'he':
      return 'Hebrew';
    case 'id':
      return 'Indonesian';
    case 'ja':
      return 'Japanese';
    case 'ko':
      return 'Korean';
    case 'lo':
      return 'Lao';
    case 'nl':
      return 'Dutch';
    case 'zh':
      return 'Chinese';
    case 'fa':
      return 'Iran';
    case 'km':
      return 'Cambodian';
    default:
      return 'Unknown';
  }
};

// Function check what's language support RTL layout 
export const isLanguageRTL = code => {
  switch (code) {
    case 'ar':
    case 'he':
      return true;
    default:
      return false;
  }
};

export const reloadLocale = (oldLanguage, newLanguage) => {
  const oldStyle = isLanguageRTL(oldLanguage);
  const newStyle = isLanguageRTL(newLanguage);
  if (oldStyle != newStyle) {
    I18nManager.forceRTL(newStyle);
    RNRestart.Restart();
  }
};