jquery.cookie中的操作之与换肤

jquery.cookie.js的插件，插件的源代码如下：

/*** Cookie plugin** Copyright (c) 2006 Klaus Hartl (stilbuero.de)* Dual licensed under the MIT and GPL licenses:* http://www.opensource.org/licenses/mit-license.php* http://www.gnu.org/licenses/gpl.html**//*** Create a cookie with the given name and value and other optional parameters.** @example $.cookie('the_cookie', 'the_value');* @desc Set the value of a cookie.* @example $.cookie('the_cookie', 'the_value', { expires: 7, path: '/', domain: 'jquery.com', secure: true });* @desc Create a cookie with all available options.* @example $.cookie('the_cookie', 'the_value');* @desc Create a session cookie.* @example $.cookie('the_cookie', null);* @desc Delete a cookie by passing null as value. Keep in mind that you have to use the same path and domain*       used when the cookie was set.** @param String name The name of the cookie.* @param String value The value of the cookie.* @param Object options An object literal containing key/value pairs to provide optional cookie attributes.* @option Number|Date expires Either an integer specifying the expiration date from now on in days or a Date object.*                             If a negative value is specified (e.g. a date in the past), the cookie will be deleted.*                             If set to null or omitted, the cookie will be a session cookie and will not be retained*                             when the the browser exits.* @option String path The value of the path atribute of the cookie (default: path of page that created the cookie).* @option String domain The value of the domain attribute of the cookie (default: domain of page that created the cookie).* @option Boolean secure If true, the secure attribute of the cookie will be set and the cookie transmission will*                        require a secure protocol (like HTTPS).* @type undefined** @name $.cookie* @cat Plugins/Cookie* @author Klaus Hartl/klaus.hartl@stilbuero.de*//*** Get the value of a cookie with the given name.** @example $.cookie('the_cookie');* @desc Get the value of a cookie.** @param String name The name of the cookie.* @return The value of the cookie.* @type String** @name $.cookie* @cat Plugins/Cookie* @author Klaus Hartl/klaus.hartl@stilbuero.de*/jQuery.cookie = function(name, value, options) {if (typeof value != 'undefined') { // name and value given, set cookieoptions = 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
        }// CAUTION: Needed to parenthesize options.path and options.domain// in the following expressions, otherwise they evaluate to undefined// in the packed version for some reason...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 cookievar 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?if (cookie.substring(0, name.length + 1) == (name + '=')) {cookieValue = decodeURIComponent(cookie.substring(name.length + 1));break;}}}return cookieValue;}
};

Cookie插件的操作

创建一个会话cookie：

$.cookie(‘cookieName’,'cookieValue’);

注：当没有指明cookie时间时，所创建的cookie有效期默认到用户浏览器关闭止，故被称为会话cookie。

创建一个持久cookie：

$.cookie(‘cookieName’,'cookieValue’，｛expires：7｝);

注：当指明时间时，故称为持久cookie，并且有效时间为天。

创建一个持久并带有效路径的cookie：

$.cookie(‘cookieName’,'cookieValue’，｛expires：7，path：’/'｝);

注：如果不设置有效路径，在默认情况下，只能在cookie设置当前页面读取该cookie，cookie的路径用于设置能够读取cookie的顶级目录。

创建一个持久并带有效路径和域名的cookie：

$.cookie(‘cookieName’,'cookieValue’，｛expires：7，path：’/'，domain: ‘chuhoo.com’，secure: false，raw:false｝);

注：domain：创建cookie所在网页所拥有的域名；secure：默认是false，如果为true，cookie的传输协议需为https；raw：默认为false，读取和写入时候自动进行编码和解码（使用encodeURIComponent编码，使用decodeURIComponent解码），关闭这个功能，请设置为true。

获取cookie：

$.cookie(‘cookieName’);   //如果存在则返回cookieValue，否则返回null。

删除cookie：

$.cookie(‘cookieName’,null);

或者这样也能删除： $.cookie('cookieName', '', { expires: -1, path: '/' }); // 删除 cookie 

注：如果想删除一个带有效路径的cookie，如下：$.cookie(‘cookieName’,null,{path:’/'});

来演示一个换肤的粟子：

代码之div+css

<link rel="stylesheet" href="styles/skin/skin_0.css" type="text/css" id="cssfile" />

<!--头部开始-->
<div id="header"><a id="logo" href="#">Jane Shopping</a><ul id="skin"><li id="skin_0" title="蓝色" class="selected">蓝色</li><li id="skin_1" title="紫色">紫色</li><li id="skin_2" title="红色">红色</li><li id="skin_3" title="天蓝色">天蓝色</li><li id="skin_4" title="橙色">橙色</li><li id="skin_5" title="淡绿色">淡绿色</li></ul></div>
<!--头部结束-->

/*切换皮肤样式*/
#skin { float:right; margin:10px; padding:4px; width:120px; list-style:none; border: 1px solid #CCCCCC; background:#FFF;
}
#skin li { float:left; margin-right:4px; width:15px; height:15px; text-indent:-9999px; overflow:hidden; display:block; cursor:pointer; background-image:url(../images/theme.gif); 
}
#skin_0 { background-position:0px 0px; }
#skin_1 { background-position:15px 0px; }
#skin_2 { background-position:35px 0px; }
#skin_3 { background-position:55px 0px; }
#skin_4 { background-position:75px 0px; }
#skin_5 { background-position:95px 0px; }
#skin_0.selected { background-position:0px 15px; }
#skin_1.selected { background-position:15px 15px; }
#skin_2.selected { background-position:35px 15px; }
#skin_3.selected { background-position:55px 15px; }
#skin_4.selected { background-position:75px 15px; }
#skin_5.selected { background-position:95px 15px; }

不同皮肤的css文件都放在styles/skins 文件夹下，命名如下：

代码之jQuery代码

版本一：

        $(function(){var $li =$("#skin li");$li.click(function(){$("#"+this.id).addClass("selected")                //当前<li>元素选中.siblings().removeClass("selected");  //去掉其它同辈<li>元素的选中$("#cssfile").attr("href","styles/skin/"+ (this.id) +".css"); //设置不同皮肤$.cookie( "MyCssSkin" ,  this.id , { path: '/', expires: 10 });});var cookie_skin = $.cookie( "MyCssSkin");//将MyCssSkin这个cookie值this.id赋给变量cookie_skinif (cookie_skin) {$("#"+cookie_skin).addClass("selected")                //当前<li>元素选中.siblings().removeClass("selected");  //去掉其它同辈<li>元素的选中$("#cssfile").attr("href","styles/skin/"+ cookie_skin +".css"); //设置不同皮肤$.cookie( "MyCssSkin" ,  cookie_skin  , { path: '/', expires: 10 });}})

版本一不好的地方，就是有大量的重复代码，可以模块化，函数化，来看版本二：

//网站换肤
$(function(){var $li =$("#skin li");$li.click(function(){switchSkin( this.id );});var cookie_skin = $.cookie("MyCssSkin");if (cookie_skin) {switchSkin( cookie_skin );}
});function switchSkin(skinName){$("#"+skinName).addClass("selected")                //当前<li>元素选中.siblings().removeClass("selected");  //去掉其他同辈<li>元素的选中$("#cssfile").attr("href","styles/skin/"+ skinName +".css"); //设置不同皮肤$.cookie( "MyCssSkin" ,  skinName , { path: '/', expires: 10 });
}

下面代码也是换肤的例子

html:

    <script>//加载皮肤文件loadCss(_skinId,'Main.css'); </script><div style="right:10px; top: 5px; position: absolute; height: 21px; text-align:right"><a>皮肤：</a><a href="#" οnclick="loadSkin('1')">藤蔓绿</a>&nbsp;<a href="#" οnclick="loadSkin('2')">经典蓝</a>&nbsp;<a href="#" οnclick="loadSkin('3')">甜蜜橙</a>&nbsp;<a href="#" οnclick="loadSkin('4')">淡雅灰</a></div>

皮肤路径 ：

js代码：

var _skinId = getCookie("_skinId") ? getCookie("_skinId"):"1";function loadSkin(skinId)
{writeCookie("_skinId",skinId);top.window.location.reload();
}function $(id)
{return document.getElementById(id);
}function loadCss(skinId,cssName)
{var head = document.getElementsByTagName('head').item(0);css = document.createElement('link');css.href = "Skin/Skin" + skinId + "/"+cssName;css.rel = 'stylesheet';css.type = 'text/css';css.id = 'loadCss';head.appendChild(css);
}function loadJs(file)
{var scriptTag = document.getElementById('loadScript');var head = document.getElementsByTagName('head').item(0);if(scriptTag) head.removeChild(scriptTag);script = document.createElement('script');script.src = "../js/mi_"+file+".js";script.type = 'text/javascript';script.id = 'loadScript';head.appendChild(script);
}function setCookie(sKey, sValue, sDomain, sPath, sExpires, blSecure)
{var sCookieStr = sKey + "=" + sValue + ";";if (sDomain)    sCookieStr += " DOMAIN=" + sDomain + ";";if (sPath)        sCookieStr += " PATH=" + sPath + ";";if (sExpires)    sCookieStr += " EXPIRES=" + sExpires + ";";if (blSecure)    sCookieStr += " SECURE";document.cookie = sCookieStr;
}function writeCookie(key,value)
{var sExpires=new Date();sExpires.setTime(sExpires.getTime()+24*60*60*1000*365);setCookie(key,value,"","",sExpires.toGMTString(),""); if(getCookie(key) == null){alert("您的浏览器安全设置过高,不支持Cookie,请重新设置浏览器的。");}
}function getCookie(sKey)
{var sCookie = document.cookie;if( !sCookie ) return null;var sTag = sKey + "=";var iBegin = sCookie.indexOf(sTag);if (iBegin < 0)    return null;iBegin += sTag.length;var iEnd = sCookie.indexOf(";", iBegin);if (iEnd < 0)    iEnd = sCookie.length;return sCookie.substring(iBegin, iEnd);
}function delCookie(sKey) 
{var tNow = new Date();setCookie(sKey, "", null, null, tNow.toGMTString(), null);
}