JS实现简单的图书馆享元模式实例

时间:2020-05-14 方方和圆圆人气:0

本文实例讲述了JS实现简单的图书馆享元模式。分享给大家供大家参考。具体如下：

<!DOCTYPE html>
<html>
<head>
<title>享员模式</title>
</head>
<body>
<script>
 /*
  *flyweight 享员模式
  */
 //例子是一个图书馆存书借书 ->_->
 var Book = function(id, title, author, genre, pageCount, publisherId, ISBN, checkoutDate, checkoutMember /*还有一些*/){
  this.id = id;
  this.title = title;
  this.author = author;
  this.genre = this.genre;
  this.pageCount = pageCount;
  this.publisherId = publisherId;
  this.ISBN = ISBN;
  /*...*/
  this.checkoutDate = checkoutDate;
  this.checkoutMember = checkoutMember;
 };
 Book.prototype = {
  getTitle : function(){
   return this.title;
  },
  getAuthor : function(){
   return this.author;
  },
  getISBN : function(){
   return this.ISBN;
  },
  /*__more.._*/
  updateCheckoutStatus : function(booId,checkoutDate,checkoutMember){
   this.id = bookId;
   this.checkoutDate = checkoutDate;
   this.checkoutMember = checkoutMember;
   /*_more.._*/
  }
 };
 //下面介绍享元的版本；PS（使用了一个OBJ存书籍，这样就可以存多的书）
 var BookFactory = (function(){
  var existingBooks = {},existingBook;
  return {
   createBook : function(title,author,genre,ISBN){
    existingBook = existingBooks[ISBN];
    if(existingBook){
     return existingBook;
    }else{
     var book = new Book(/*_moreData_bookInfo == _*/)
     return existingBooks[ISBN] = book;
    }
   }
  }
 })();
 var BookRecordManager = (function(){
  var bookRecordDatabase = {};
  return {
   addBookRecord : function(id,ISNB/* == */){
    var book = BookFactory.createBook(/**/);
    bookRecordDatabase[id] = {
     checkoutDate : checkoutDate,
     checkoutMember : checkoutMember
    };
   },
   updateCheckoutStatus : function(bookId,xx){
    bookRecordDatabase[bookId] = {
     xx : tt,
     oo : yy
    }
   },
   extend : function(){
    /*自定义各种公用方法了*/
   }
  }
 })();
</script>
</body>
</html>

希望本文所述对大家的javascript程序设计有所帮助。

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