[JavaScript] DAO pattern with Reflect

data_access_sample.js

// DataModel
class UserModel {
  constructor(data = {}) {
    this.id = data.id ?? null;
    this.name = data.name ?? '';
  }
}

class BookModel {
  constructor(data = {}) {
    this.id = data.id ?? null;
    this.title = data.title ?? '';
  }
}

// Storage
const memory = new Map();

// DAO
function DataAccess (key, model) {
  return class {
    static save (value) {
      const data = Reflect.construct(model, [value]);
      memory.set(key, data);
    }
    static load () {
      const data = memory.get(key);
      return Reflect.construct(model, [data]);
    }
  }
}

class User extends DataAccess('user', UserModel) {
  constructor() {
    super();
  }
}

class Book extends DataAccess('book', BookModel) {
  constructor() {
    super();
  }
  /**
   * @param {BookModel} data
   */
  static save (data) {
    // do something...
    super.save(data);
  }
}


User.save({ id: 1, name: 'hoge' });
console.log(User.load());

const newBook = new BookModel();
newBook.id = 123;
newBook.title = 'new book';
Book.save(newBook);

console.log(Book.load());