Method selectLocaleAsync

modules/core/LocalizationSystem.js:196–220

* _selectLocale * Returns a Promise to select the locale. * @return {Promise} Promise resolved when the locale has been selected and strings loaded

()

   * @return {Promise}  Promise resolved when the locale has been selected and strings loaded
   */
  selectLocaleAsync() {
    const urlhash = this.context.systems.urlhash;
    const urlLocale = urlhash.getParam('locale');
    let urlLocaleCodes = [];
    if (typeof urlLocale === 'string') {
      urlLocaleCodes = urlLocale.split(',').map(s => s.trim()).filter(Boolean);
    }

    // Choose the preferred locales in this order:
    //   1. Locales stored in `_preferredLocaleCodes`
    //   2. Locales included in the url hash
    //   3. Locales detected by the browser
    //   4. English (always fallback)
    const requestedLocales = (this._preferredLocaleCodes || [])
      .concat(urlLocaleCodes)
      .concat(utilDetect().locales)   // Locales preferred by the browser in priority order.
      .concat(['en']);                // Fallback to English since it's the only guaranteed complete language

    this._currLocaleCodes = this._getSupportedLocales(requestedLocales);
    this._currLocaleCode = this._currLocaleCodes[0];   // First is highest priority locale; the rest are fallbacks

    const loadPromises = this._currLocaleCodes.map(locale => this._loadStringsAsync(locale));
    return Promise.all(loadPromises)
      .then(() => this._localeChanged());
  }


  /**