什么是cookie?cookie就是页面用来保存信息,比如自动登录、记住用户名等等。cookie的特点同
什么是 cookie?
cookie 就是页面用来保存信息,比如自动登录、记住用户名等等。
cookie 的特点
- 同个网站中所有的页面共享一套 cookie
- cookie 有数量、大小限制
- cookie 有过期时间jquery.cookie.js 是一款轻量级的 cookie 插件,可以读取,写入和删除 cookie。本文主要针对
jquery.cookie.js 的用法进行详细的介绍。
jquery.cookie.js 使用方法
Cookies
定义:让网站服务器把少量数据储存到客户端的硬盘或内存,从客户端的硬盘读取数据的一种技术;
下载与引入:jquery.cookie.js基于jquery;先引入jquery,再引入:jquery.cookie.js;
下载:http://plugins.jquery.com/cookie/
<script type="text/javascript" src="js/jquery.min.js"></script> <script type="text/javascript" src="js/jquery.cookie.js"></script>
使用:
1.添加一个"会话cookie"
$.cookie('the_cookie', 'the_value');
这里没有指明 cookie有效时间,所创建的cookie有效期默认到用户关闭浏览器为止,所以被称为 “会话cookie(session cookie)”。
2.创建一个cookie并设置有效时间为 7天
$.cookie('the_cookie', 'the_value', { expires: 7 });
这里指明了cookie有效时间,所创建的cookie被称为“持久 cookie (persistent cookie)”。注意单位是:天;
3.创建一个cookie并设置 cookie的有效路径
$.cookie('the_cookie', 'the_value', { expires: 7, path: '/' });
在默认情况下,只有设置 cookie的网页才能读取该 cookie。如果想让一个页面读取另一个页面设置的cookie,必须设置cookie的路径。cookie的路径用于设置能够读取 cookie的顶级目录。将这个路径设置为网站的根目录,可以让所有网页都能互相读取 cookie (一般不要这样设置,防止出现冲突)。
4.读取cookie
$.cookie('the_cookie');
5.删除cookie
$.cookie('the_cookie', null); //通过传递null作为cookie的值即可
6.可选参数
$.cookie('the_cookie','the_value',{
expires:7,
path:'/',
domain:'jquery.com',
secure:true
})
expires:(Number|Date)有效期;设置一个整数时,单位是天;也可以设置一个日期对象作为Cookie的过期日期; path:(String)创建该Cookie的页面路径; domain:(String)创建该Cookie的页面域名; secure:(Booblean)如果设为true,那么此Cookie的传输会要求一个安全协议,例如:HTTPS;
使用方法:
设置 cookie:
$.cookie('the_cookie', 'the_value');
注:如果 $.cookie
没有第三个参数,那么当浏览器关闭时,该 cookie 将会自动删除。
设置一个有效期为 7 天的 cookie:
$.cookie('the_cookie', 'the_value', {expires: 7});
注:$.cookie
第三个参数是一个对象,除了可以设置有效期(expires: 7
),还可以设置有效路径(path: '/'
)、有效域(domain: 'jquery.com'
)及安全性(secure: true
)。
读取 cookie:
$.cookie('the_cookie');
注:如果没有该 cookie,返回 null。
删除 cookie:
$.cookie('the_cookie', null);
我们只需要给需要删除的 cookie 设置为 null,就可以删除该 cookie。
最后附上源代码:
/**
* 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 cookie
options = options || {};
if (value === null) {
value = '';
options = $.extend({}, options); // clone object since it's unexpected behavior if the expired property were changed
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
}
// NOTE 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 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?
if (cookie.substring(0, name.length + 1) == (name + '=')) {
cookieValue = decodeURIComponent(cookie.substring(name.length + 1));
break;
}
}
}
return cookieValue;
}
};
总结
以上就是这篇文章的全部内容了,希望本文的内容对大家的学习或者工作能带来一定的帮助,如果有疑问大家可以留言交流。
jquery.cookie.js使用 jquery.cookie.js