ng-alain: i18n

https://github.com/ng-alain/delon/blob/master/packages/theme/src/services/i18n/i18n.ts

• interface AlainI18NService
• abstract class AlainI18nBaseService implements AlainI18NService
• class AlainI18NServiceFake

支持占位符的定制，默认使用 {{ }}，可以通过 AlainConfigService 的 interpolation 进行定制。使用了其中的 'themeI18n' 部分的定义

提供了一个 flatData() 可以将层次嵌套的结构平铺为单层的对象结构。

/**
   * Flattened data source
   *
   * @example
   * {
   *   "name": "Name",
   *   "sys": {
   *     "": "System",
   *     "title": "Title"
   *   }
   * }
   * =>
   * {
   *   "name": "Name",
   *   "sys": "System",
   *   "sys.title": "Title"
   * }
   */
  flatData(data: Record<string, unknown>, parentKey: string[]): Record<string, string> {
    const res: Record<string, string> = {};
    for (const key of Object.keys(data)) {
      const value = data[key];
      if (typeof value === 'object') {
        const child = this.flatData(value as Record<string, unknown>, parentKey.concat(key));
        Object.keys(child).forEach(childKey => (res[childKey] = child[childKey]));
      } else {
        res[(key ? parentKey.concat(key) : parentKey).join('.')] = `${value}`;
      }
    }
    return res;
  }