BezierInfo-2/tools/locale-strings.js

const defaultLocale = "en-GB";

const localeStringData = {
  title: {
    "en-GB": "A Primer on Bézier Curves",
    "ja-JP": "ベジェ曲線入門",
    "zh-CN": "贝塞尔曲线底漆",
  },
  subtitle: {
    "en-GB":
      "A free, online book for when you really need to know how to do Bézier things.",
  },
  description: {
    "en-GB":
      "A detailed explanation of Bézier curves, and how to do the many things that we commonly want to do with them.",
  },
  tocLabel: {
    "en-GB": "Table of Contents",
    "ja-JP": "目次",
    "zh-CN": "目录",
  },
  localeName: {
    "en-GB": "English",
    "zh-CN": "中文",
    "ja-JP": "日本語",
  },
  langSwitchLabel: {
    "en-GB": "Read this in your own language:",
  },
  langHelpLabel: {
    "en-GB":
      'Don\'t see your language listed? <a href="https://github.com/Pomax/BezierInfo-2/wiki/localize">Help translate this content!</a>',
  },
  disabledMessage: {
    "en-GB": "Scripts are disabled. Showing fallback image.",
  },
  changelogTitle: {
    "en-GB": "What's new?",
  },
  changelogDescription: {
    "en-GB":
      "This primer is a living document, and so depending on when you last look at it, there may be new content. Click the following link to expand this section to have a look at what got added, when.",
  },
};

class LocaleStrings {
  constructor(locale) {
    this.currentLocale = locale;
    const strings = (this.strings = {});

    Object.keys(localeStringData).forEach((id) => {
      const map = localeStringData[id];
      if (typeof map !== "object") return;
      const value = map[locale] ?? map[defaultLocale];
      if (!value) throw new Error(`unknown locale string id "${id}".`);
      strings[id] = value;

      // temporary bug catcher:
      Object.defineProperty(this, id, {
        get: () => {
          throw new Error(`cannot get localestring ${id} via property access`);
        },
      });
    });
  }
  // templating tags:

  get translate() {
    return this.get.bind(this);
  }

  // functions:

  get(id) {
    return this.strings[id];
  }

  getDefaultLocale() {
    return defaultLocale;
  }

  getCurrentLocale() {
    return this.currentLocale;
  }

  getLocaleName(locale) {
    const name = localeStringData.localeName[locale];
    if (!name) {
      throw new Error(`Unknown locale "${locale}"`);
    }
    return name;
  }

  getAllLocaleCodes() {
    return Object.keys(localeStringData.title);
  }

  extendContext(context) {
    const strings = this.strings;

    Object.keys(strings).forEach((key) => {
      if (context[key]) {
        throw new Error(`Context already has key "${key}"!`);
      }
      context[key] = strings[key];
    });
  }
}

export default LocaleStrings;