本文实例讲述了PHP实现动态压缩js与css文件的方法。分享给大家供大家参考，具体如下：
正式发布产品时，我们希望将项目里的js，css合并压缩，以减少http请求、防止轻易查看源代码。
使用
只需要在头部引入一下代码即可：
<meta charset="utf-8"/> <title>demo</title> <?php //定义需要压缩的文件 $css = array( CSS_PATH . 'base.css', CSS_PATH . 'style.css', CSS_PATH . 'my.css' ); $js = array( PUB_PATH . '/lib/zepto.min.js', PUB_PATH . '/js/1.js', JS_PATH . '2.js', ); $css_path = base_url(parse_css($css)); $js_path = base_url(parse_script($js)); ?> <link rel="stylesheet" type="text/css" href="<?php echo $css_path ?>" rel="external nofollow" > <script src="<?php echo $js_path ?>"></script> <!--下面可以继续放不能压缩或者不想压缩的文件--> <script src="http://res.wx.qq.com/open/js/jweixin-1.0.0.js"></script>
这段代码会在指定的目录(例如common/)里生成压缩过后的js和css.每次更新了js,css内容，请先删除生成的压缩文件。
示例：
4e387d5edce14cc2bd6396f6ebb7921b.css 7c10211f113f3175489196d336d67734.js
注意：
编写的css和js文件一定要符合规范。例如一定要加分号。js的function可以不加分号。
引用的资源
/**
* 合并压缩css
*/
function parse_css($urls)
{
$url = md5(implode(',', $urls));
$path = FCPATH. 'static/parse/';
$css_url = $path . $url . '.css';
if (!file_exists($css_url)) {
if (!file_exists($path))
mkdir($path, 0777);
$css_content = '';
foreach ($urls as $url) {
$css_content .= @file_get_contents($url);
}
$css_content = str_replace("\r\n", '', $css_content); //清除换行符
$css_content = str_replace("\n", '', $css_content); //清除换行符
$css_content = str_replace("\t", '', $css_content); //清除制表符
$css_content = str_replace("../images/", "./../common/images/", $css_content);
@file_put_contents($css_url, $css_content);
}
$css_url = str_replace(FCPATH, '', $css_url);
return $css_url;
}
/**
* 合并压缩js
*/
function parse_script($urls)
{
$url = md5(implode(',', $urls));
$path = FCPATH. '/static/parse/';
$js_url = $path . $url . '.js';
if (!file_exists($js_url)) {
if (!file_exists($path))
mkdir($path, 0777);
load_qy_lib('JavaScriptPacker');
$js_content = '';
foreach ($urls as $url) {
$append_content = @file_get_contents($url) . "\r\n";
$packer = new JavaScriptPacker($append_content);
$append_content = $packer->_basicCompression($append_content);
$js_content .= $append_content;
}
@file_put_contents($js_url, $js_content);
}
$js_url = str_replace(FCPATH, '', $js_url);
return $js_url;
}
项目里引用到第三方类库JavaScriptPacker可以在github下载：
gkralik/php-uglifyjs
https://github.com/gkralik/php-uglifyjs
/** * 9 April 2008. version 1.1 * * This is the php version of the Dean Edwards JavaScript's Packer, * Based on : * * ParseMaster, version 1.0.2 (2005-08-19) Copyright 2005, Dean Edwards * a multi-pattern parser. * KNOWN BUG: erroneous behavior when using escapeChar with a replacement * value that is a function * * packer, version 2.0.2 (2005-08-19) Copyright 2004-2005, Dean Edwards * * License: http://creativecommons.org/licenses/LGPL/2.1/ * * Ported to PHP by Nicolas Martin. * * ---------------------------------------------------------------------- * changelog: * 1.1 : correct a bug, '\0' packed then unpacked becomes '\'. * ---------------------------------------------------------------------- * * Changes: * 2014-08-28: grkalik: change class for composer support. no functionality change. * */
PS：这里再为大家推荐几款相似的在线工具供大家参考：
JavaScript压缩/格式化/加密工具：
http://tools.jb51.net/code/jscompress
在线CSS代码压缩、格式化工具：
http://tools.jb51.net/code/css
希望本文所述对大家PHP程序设计有所帮助。
