php压缩html代码

优点:网络请求文件大小

    /**
     * Name: 压缩html代码
     * @param string $html_source
     * @return string
     */
    static public function compressHtml($html_source){
//        return trim(preg_replace(["/> *([^ ]*) *</","//","'/\*[^*]*\*/'","/\r\n/","/\n/","/\t/",'/>[ ]+</',"/ 0=['\"](.*?)['\"]/"], [">\\1<",'','','','','','><',''],$html_source));
        $chunks   = preg_split('/(<!--<nocompress>-->.*?<!--<\/nocompress>-->|<nocompress>.*?<\/nocompress>|<pre.*?\/pre>|<textarea.*?\/textarea>|<script.*?\/script>)/msi', $html_source, -1, PREG_SPLIT_DELIM_CAPTURE);
        $compress = '';
        foreach ($chunks as $c) {
            if (strtolower(substr($c, 0, 19)) == '<!--<nocompress>-->') {
                $c        = substr($c, 19, strlen($c) - 19 - 20);
                $compress .= $c;
                continue;
            } elseif (strtolower(substr($c, 0, 12)) == '<nocompress>') {
                $c        = substr($c, 12, strlen($c) - 12 - 13);
                $compress .= $c;
                continue;
            } elseif (strtolower(substr($c, 0, 4)) == '<pre' || strtolower(substr($c, 0, 9)) == '<textarea') {
                $compress .= $c;
                continue;
            } elseif (strtolower(substr($c, 0, 7)) == '<script' && strpos($c, '//') != false && (strpos($c, "\r") !== false || strpos($c, "\n") !== false)) { // JS代码，包含“//”注释的，单行代码不处理
                $tmps = preg_split('/(\r|\n)/ms', $c, -1, PREG_SPLIT_NO_EMPTY);
                $c    = '';
                foreach ($tmps as $tmp) {
                    if (strpos($tmp, '//') !== false) { // 对含有“//”的行做处理
                        if (substr(trim($tmp), 0, 2) == '//') { // 开头是“//”的就是注释
                            continue;
                        }
                        $chars   = preg_split('//', $tmp, -1, PREG_SPLIT_NO_EMPTY);
                        $is_quot = $is_apos = false;
                        foreach ($chars as $key => $char) {
                            if ($char == '"' && !$is_apos && $key > 0 && $chars[$key - 1] != '\\') {
                                $is_quot = !$is_quot;
                            } elseif ($char == '\'' && !$is_quot && $key > 0 && $chars[$key - 1] != '\\') {
                                $is_apos = !$is_apos;
                            } elseif ($char == '/' && $chars[$key + 1] == '/' && !$is_quot && !$is_apos) {
                                $tmp = substr($tmp, 0, $key); // 不是字符串内的就是注释
                                break;
                            }
                        }
                    }
                    $c .= $tmp;
                }
            }
            $c = preg_replace('/[\\n\\r\\t]+/', ' ', $c); // 清除换行符，清除制表符
            $c = preg_replace('/\\s{2,}/', ' ', $c); // 清除额外的空格
            $c = preg_replace('/>\\s</', '> <', $c); // 清除标签间的空格
            $c = preg_replace('/\\/\\*.*?\\*\\//i', '', $c); // 清除 CSS & JS 的注释
            $c = preg_replace('/<!--[^!]*-->/', '', $c); // 清除 HTML 的注释
            $compress .= $c;
        }
        return $compress;
    }