flyweightPattern-2.js

var Book = function(
    id,
    title,
    author,
    genre,
    pageCount,
    publisherID,
    ISBN,
    checkoutDate,
    checkoutMember,
    dueReturnDate,
    availability
  ) {
    this.id = id;
    this.title = title;
    this.author = author;
    this.genre = genre;
    this.pageCount = pageCount;
    this.publisherID = publisherID;
    this.ISBN = ISBN;
    this.checkoutDate = checkoutDate;
    this.checkoutMember = checkoutMember;
    this.dueReturnDate = dueReturnDate;
    this.availability = availability;
  };
  
  Book.prototype = {
    getTitle: function() {
      return this.title;
    },
  
    getAuthor: function() {
      return this.author;
    },
  
    getISBN: function() {
      return this.ISBN;
    },
  
    // For brevity, other getters are not shown
    updateCheckoutStatus: function(
      bookID,
      newStatus,
      checkoutDate,
      checkoutMember,
      newReturnDate
    ) {
      this.id = bookID;
      this.availability = newStatus;
      this.checkoutDate = checkoutDate;
      this.checkoutMember = checkoutMember;
      this.dueReturnDate = newReturnDate;
    },
  
    extendCheckoutPeriod: function(bookID, newReturnDate) {
      this.id = bookID;
      this.dueReturnDate = newReturnDate;
    },
  
    isPastDue: function(bookID) {
      var currentDate = new Date();
      return currentDate.getTime() > Date.parse(this.dueReturnDate);
    }
  };


  //NEW VERSION
  // Flyweight optimized version
var Book = function(title, author, genre, pageCount, publisherID, ISBN) {
    this.title = title;
    this.author = author;
    this.genre = genre;
    this.pageCount = pageCount;
    this.publisherID = publisherID;
    this.ISBN = ISBN;
  };