怎样使用php与jquery设置和读取cookies
有两种处理cookies的方式―服务端(php,asp等)和客户端(javascript).在这个教程中,我们将学习到以php和javascript这两种方式如何去创建cookies
HTTP协议是一种无状态协议,这意味着你对网站的每一个请求都是独立的,而且因此无法通过它自身保存数据。但这种简单性也是它在互联网早期就广泛传播的原因之一。
不过,它仍然有一种方法能让你用cookies的形式来保存请求之间的信息。这种方法使你能够更有效率的进行会话管理和维持数据。
有两种处理cookies的方式―服务端(php,asp等)和客户端(javascript).在这个教程中,我们将学习到以php和javascript这两种方式如何去创建cookies。
Cookies and php
setting cookies
在php中创建cookie你需要用到setcookie这个方法。它需要些参数(除了第一个参数是必需的,其它参数都是可选的)
setcookie( 'pageVisits', //cookie名字,必需的 $visited, //cookie的值 time()+7*24*60*60, //过期时间,设置为一个星期 '/', //cookie可用的文件路径 'demo.tutorialzine.com' //cookie绑定的域名 )
如果过期时间设置为0(默认设置也是0),那么当浏览器重启时cookie将会丢失。
参数'/'表示你域名下所有文件路径cookie都可以用(当然你也可以为它设置单一的文件路径,例:'/admin/')。
你还可以传给个这个函数别两个额外的参数,这里没有给出。它们被规定为boolean类型的。
第一个参数表示cookie仅在一个安全的HTTPS连接才运转,而第二个参数表示不能使用javascript操作cookie。
对大多数人来说,你只需要第四个参数,剩下的就忽略了。
reading cookies
用php读取cookie就简单多了。所有的传给脚本的cookies都在$_COOKIE这个超级全局数组里。
在我们的例子里,可以用下面的代码来读取cookies:
$visits = (int)$_COOKIE['pageVisits']+1; echo "You visited this site: ".$visits." times";
值得注意的地方是,当下一个页面加载好时,也可以用$_COOKIE来取得你用setcookie方法设置的cookies,
你应该意识到了什么。
deleting cookies
为了删除cookies,仅仅需要用setcookie函数为cookies设置一个已经过去时间做为过期就行了。
setcookie( 'pageVisits', $visited, time()-7*24*60*60, //设置为前一个星期,cookie将会被删除 '/', 'demo.tutorialzine.com' )
Cookies and jQuery
在jquery中使用cookies,你需要一个插件Cookie plugin.
Setting cookies
用Cookie plug-in设置cookies是很直观的:
$(document).ready(function(){ // Setting a kittens cookie, it will be lost on browser restart: $.cookie("kittens","Seven Kittens"); // Setting demoCookie (as seen in the demonstration): $.cookie("demoCookie",text,{expires: 7, path: '/', domain: 'demo.tutorialzine.com'}); // "text" is a variable holding the string to be saved });
Reading cookies
读取cookie甚至更简单,只需要调用$.cookie()方法,给它一个cookie-name就可以了,这个方法会返回cookie的值:
$(document).ready(function(){ // Getting the kittens cookie: var str = $.cookie("kittens"); // str now contains "Seven Kittens" });
Deleting cookies
删除cookie,只需要在次使得$.cookie()方法,把第二个参数设置为null就可以了。
$(document).ready(function(){ // Deleting the kittens cookie: var str = $.cookie("kittens",null); // No more kittens });
完整例子:
demo.php
<?php // Always set cookies before any data or HTML are printed to the page $visited = (int)$_COOKIE['pageVisits'] + 1; setcookie( 'pageVisits', // Name of the cookie, required $visited, // The value of the cookie time()+7*24*60*60, // Expiration time, set for a week in the future '/', // Folder path, the cookie will be available for all scripts in every folder of the site 'demo.tutorialzine.com'); // Domain to which the cookie will be locked ?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>MicroTut: Getting And Setting Cookies With jQuery & PHP | Tutorialzine demo</title> <link rel="stylesheet" type="text/css" href="styles.css" mce_href="styles.css" /> <mce:script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js" mce_src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></mce:script> <mce:script type="text/javascript" src="jquery.cookie.js" mce_src="jquery.cookie.js"></mce:script> <mce:script type="text/javascript"><!-- $(document).ready(function(){ var cookie = $.cookie('demoCookie'); // If the cookie has been set in a previous page load, show it in the div directly: if(cookie) $('.jq-text').text(cookie).show(); $('.fields a').click(function(e){ var text = $('#inputBox').val(); // Setting a cookie with a seven day validity: $.cookie('demoCookie',text,{expires: 7, path: '/', domain: 'demo.tutorialzine.com'}); $('.jq-text').text(text).slideDown('slow'); e.preventDefault(); }); $('#form1').submit(function(e){ e.preventDefault(); }) }) // --></mce:script> </head> <body> <h1>MicroTut: Getting And Setting Cookies With jQuery & PHP</h1> <h2>Go Back <a href="http://tutorialzine.com/2010/03/microtut-getting-setting-cookies-jquery-php/" mce_href="http://tutorialzine.com/2010/03/microtut-getting-setting-cookies-jquery-php/">To The Tutorial »</a></h2> <div class="section"> <div class="counter"><?php echo $visited?></div> <p>The number above indicates how many times you've visited this page (PHP cookie). Reload to test.</p> </div><div class="section"> <div class="jq-text"></div> <form action="" method="get" id="form1"> <div class="fields"> <input type="text" id="inputBox" /> <a href="">Save</a> </div> </form> <p>Write some text in the field above and click Save. It will be saved between page reloads with a jQuery cookie.</p> </div> </body> </html>
jquery.cookie.js
/** * 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/[email protected] */ /** * 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/[email protected] */ 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 } // 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 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; } };
styles.css
*{ margin:0; padding:0; } body{ /* Setting default text color, background and a font stack */ color:#555555; font-size:0.825em; background: #fcfcfc; font-family:Arial, Helvetica, sans-serif; } .section{ margin:0 auto 60px; text-align:center; width:600px; } .counter{ color:#79CEF1; font-size:180px; } .jq-text{ display:none; color:#79CEF1; font-size:80px; } p{ font-size:11px; padding:0 200px; } form{ margin-bottom:15px; } input[type=text]{ border:1px solid #BBBBBB; color:#444444; font-family:Arial,Verdana,Helvetica,sans-serif; font-size:14px; letter-spacing:1px; padding:2px 4px; } /* The styles below are only necessary for the styling of the demo page: */ h1{ background:#F4F4F4; border-bottom:1px solid #EEEEEE; font-size:20px; font-weight:normal; margin-bottom:15px; padding:15px; text-align:center; } h2 { font-size:12px; font-weight:normal; padding-right:40px; position:relative; right:0; text-align:right; text-transform:uppercase; top:-48px; } a, a:visited { color:#0196e3; text-decoration:none; outline:none; } a:hover{ text-decoration:underline; } .clear{ clear:both; } h1,h2,p.tutInfo{ font-family:"Myriad Pro",Arial,Helvetica,sans-serif; }
结束语:
关于cookie的使用,你需要注意的是不要把一些敏感信息(例如用户名、密码)保存在cookies中,
为因当每一个页面加载时cookies都会和headers一样传递到页面,很容易被不法份子截取到。
但是,只要有适当的预防措施,你就可以用这个简单的技术实现大量的互动。