jQuery's method of implementing a shopping cart based on json and cookies_jquery

The example in this article describes how jQuery implements a shopping cart based on json and cookies. Share it with everyone for your reference, the details are as follows:

json format:

[{'ProductID':ABC','Num':'1'},{'ProductID':DEF,'Num':'2'}]

The $.cookie plug-in is used here. The code of this plug-in is at the end of the article

/*
添加商品及数量到购物车cookie中,返回当前商品在cookie中的总数
*/
function AddToShoppingCar(id, num) {
  var _num = 1;
  if (num != undefined)
    _num = num;
  var totalNum = _num; //总数默认为传入参数
  var cookieSet = { expires: 7, path: '/' }; //设置cookie路径的
//  $.cookie(cookieProductID, null, cookieSet);//清除Cookie
  var jsonStr = "[{'ProductID':'" + id + "','Num':'" + _num + "'}]"; //构造json字符串,id是商品id  num是这个商品的数量
  if ($.cookie(cookieProductID) == null) {
    $.cookie(cookieProductID, jsonStr, cookieSet); //如果没有这个cookie就设置他
  }
  else {
    var jsonObj = eval('(' + $.cookie(cookieProductID) + ')'); //如果有，把json字符串转换成对象
    var findProduct = false;//是否找到产品ID,找到则为TRUE,否则为FALSH
    for (var obj in jsonObj) {
      if (jsonObj[obj].ProductID == id) {
        jsonObj[obj].Num = Number(jsonObj[obj].Num) + _num;
        totalNum = jsonObj[obj].Num;
        findProduct = true;
        break;
      }
    }
    if (findProduct == false) { //没找到,则添加
      jsonObj[jsonObj.length] = new Object();
      jsonObj[jsonObj.length - 1].ProductID = id;
      jsonObj[jsonObj.length - 1].Num = num;
    }
    $.cookie(cookieProductID, JSON.stringify(jsonObj), cookieSet); //写入coockie  JSON需要json2.js支持
  }
  return totalNum;
  //  alert($.cookie(cookieProductID));
}

//以下为cookie插件代码
jQuery.cookie = function(name, value, options) {
  if (typeof value != 'undefined') { // name and value given, set cookie
    options = options || {};
    if (value === null) {
      value = '';
      options.expires = -1;
    }
    var expires = '';
    if (options.expires && (typeof options.expires == 'number' || options.expires.toUTCString)) {
      var date;
      if (typeof options.expires == 'number') {
        date = new Date();
        date.setTime(date.getTime() + (options.expires * 24 * 60 * 60 * 1000));
      } else {
        date = options.expires;
      }
      expires = '; expires=' + date.toUTCString(); // use expires attribute, max-age is not supported by IE
    }
    var path = options.path ? '; path=' + options.path : '';
    var domain = options.domain ? '; domain=' + options.domain : '';
    var secure = options.secure ? '; secure' : '';
    document.cookie = [name, '=', encodeURIComponent(value), expires, path, domain, secure].join('');
  } else { // only name given, get cookie
    var cookieValue = null;
    if (document.cookie && document.cookie != '') {
      var cookies = document.cookie.split(';');
      for (var i = 0; i < cookies.length; i++) {
        var cookie = jQuery.trim(cookies[i]);
        // Does this cookie string begin with the name we want&#63;
        if (cookie.substring(0, name.length + 1) == (name + '=')) {
          cookieValue = decodeURIComponent(cookie.substring(name.length + 1));
          break;
        }
      }
    }
    return cookieValue;
  }
};

Readers who are interested in more jQuery-related content can check out the special topics on this site: "JQuery cookie operation skills summary", "jQuery table (table) operation skills summary" , "Summary of jQuery drag effects and techniques", "Summary of jQuery extension techniques", "Summary of jQuery common classic special effects", "jQuery animation and special effects usage summary", "jquery selector usage summary" and "jQuery common plug-ins and usage summary"

I hope this article will be helpful to everyone in jQuery programming.