2656 /**

  2657  * Sanitizes a page tag.

  2658  * @param string

  2659  * @return string

  2660  */

  2661 

  2662 function sanitize_tag($tag)

  2663 {

  2664   $tag = strtolower($tag);

  2665   $tag = preg_replace('/[^\w _-]+/', '', $tag);

  2666   $tag = trim($tag);

  2667   return $tag;

  2668 }

  2669 

  2670 /**

  2671  * Gzips the output buffer.

  2672  */

  2673 

  2674 function gzip_output()

  2675 {

  2676   global $do_gzip;

  2677   

  2678   //

  2679   // Compress buffered output if required and send to browser

  2680   //

  2681   if ( $do_gzip && function_exists('ob_gzhandler') )

  2682   {

  2683     //

  2684     // Copied from phpBB, which was in turn borrowed from php.net

  2685     //

  2686     $gzip_contents = ob_get_contents();

  2687     ob_end_clean();

  2688     

  2689     header('Content-encoding: gzip');

  2690     $gzip_contents = ob_gzhandler($gzip_contents);

  2691     echo $gzip_contents;

  2692   }

  2693 }

  2694 

  2695 /**

  2696  * Aggressively and hopefully non-destructively optimizes a blob of HTML.

  2697  * @param string HTML to process

  2698  * @return string much snaller HTML

  2699  */

  2700 

  2701 function aggressive_optimize_html($html)

  2702 {

  2703   $size_before = strlen($html);

  2704   

  2705   // kill carriage returns

  2706   $html = str_replace("\r", "", $html);

  2707   

  2708   // Optimize (but don't obfuscate) Javascript

  2709   preg_match_all('/<script(.*?)>(.+?)<\/script>/is', $html, $jscript);

  2710   

  2711   // list of Javascript reserved words - from about.com

  2712   $reserved_words = array('abstract', 'as', 'boolean', 'break', 'byte', 'case', 'catch', 'char', 'class', 'continue', 'const', 'debugger', 'default', 'delete', 'do',

  2713                           'double', 'else', 'enum', 'export', 'extends', 'false', 'final', 'finally', 'float', 'for', 'function', 'goto', 'if', 'implements', 'import',

  2714                           'in', 'instanceof', 'int', 'interface', 'is', 'long', 'namespace', 'native', 'new', 'null', 'package', 'private', 'protected', 'public',

  2715                           'return', 'short', 'static', 'super', 'switch', 'synchronized', 'this', 'throw', 'throws', 'transient', 'true', 'try', 'typeof', 'use', 'var',

  2716                           'void', 'volatile', 'while', 'with');

  2717   

  2718   $reserved_words = '(' . implode('|', $reserved_words) . ')';

  2719   

  2720   for ( $i = 0; $i < count($jscript[0]); $i++ )

  2721   {

  2722     $js =& $jscript[2][$i];

  2723     

  2724     // for line optimization, explode it

  2725     $particles = explode("\n", $js);

  2726     

  2727     foreach ( $particles as $j => $atom )

  2728     {

  2729       // Remove comments

  2730       $atom = preg_replace('#\/\/(.+)#i', '', $atom);

  2731       

  2732       $atom = trim($atom);

  2733       if ( empty($atom) )

  2734         unset($particles[$j]);

  2735       else

  2736         $particles[$j] = $atom;

  2737     }

  2738     

  2739     $js = implode("\n", $particles);

  2740     

  2741     $js = preg_replace('#/\*(.*?)\*/#s', '', $js);

  2742     

  2743     // find all semicolons and then linebreaks, and replace with a single semicolon

  2744     $js = str_replace(";\n", ';', $js);

  2745     

  2746     // starting braces

  2747     $js = preg_replace('/\{([\s]+)/m', '{', $js);

  2748     $js = str_replace(")\n{", '){', $js);

  2749     

  2750     // ending braces (tricky)

  2751     $js = preg_replace('/\}([^;])/m', '};\\1', $js);

  2752     

  2753     // other rules

  2754     $js = str_replace("};\n", "};", $js);

  2755     $js = str_replace(",\n", ',', $js);

  2756     $js = str_replace("[\n", '[', $js);

  2757     $js = str_replace("]\n", ']', $js);

  2758     $js = str_replace("\n}", '}', $js);

  2759     

  2760     // newlines immediately before reserved words

  2761     $js = preg_replace("/(\)|;)\n$reserved_words/is", '\\1\\2', $js);

  2762     

  2763     // fix for firefox issue

  2764     $js = preg_replace('/\};([\s]*)(else|\))/i', '}\\2', $js);

  2765     

  2766     // apply changes

  2767     $html = str_replace($jscript[0][$i], "<script{$jscript[1][$i]}>$js</script>", $html);

  2768   }

  2769   

  2770   // Which tags to strip - you can change this if needed

  2771   $strip_tags = Array('pre', 'script', 'style', 'enano:no-opt');

  2772   $strip_tags = implode('|', $strip_tags);

  2773   

  2774   // Strip out the tags and replace with placeholders

  2775   preg_match_all("#<($strip_tags)(.*?)>(.*?)</($strip_tags)>#is", $html, $matches);

  2776   $seed = md5(microtime() . mt_rand()); // Random value used for placeholders

  2777   for ($i = 0;$i < sizeof($matches[1]); $i++)

  2778   {

  2779     $html = str_replace($matches[0][$i], "{DONT_STRIP_ME_NAKED:$seed:$i}", $html);

  2780   }

  2781   

  2782   // Finally, process the HTML

  2783   $html = preg_replace("#\n([ ]*)#", " ", $html);

  2784   

  2785   // Remove annoying spaces between tags

  2786   $html = preg_replace("#>([ ][ ]+)<#", "> <", $html);

  2787   

  2788   // Re-insert untouchable tags

  2789   for ($i = 0;$i < sizeof($matches[1]); $i++)

  2790   {

  2791     $html = str_replace("{DONT_STRIP_ME_NAKED:$seed:$i}", "<{$matches[1][$i]}{$matches[2][$i]}>{$matches[3][$i]}</{$matches[4][$i]}>", $html);

  2792   }

  2793   

  2794   // Remove <enano:no-opt> blocks (can be used by themes that don't want their HTML optimized)

  2795   $html = preg_replace('#<(\/|)enano:no-opt(.*?)>#', '', $html);

  2796   

  2797   $size_after = strlen($html);

  2798   

  2799   // Tell snoopish users what's going on

  2800   $html = str_replace('<html>', "\n".'<!-- NOTE: Enano has performed an HTML optimization routine on the HTML you see here. This is to enhance page loading speeds.

  2801      To view the uncompressed source of this page, add the "nocompress" parameter to the URI of this page: index.php?title=Main_Page&nocompress or Main_Page?nocompress'."

  2802      Size before compression: $size_before bytes

  2803      Size after compression:  $size_after bytes

  2804      -->\n<html>", $html);

  2805   return $html;

  2806 }

  2807