beautify.php

<?php
/**
 * Beautify
 * Combines four text tools into one function
 * - Markdown: Simpeler and more readable than HTML
 * - SmartyPants: Better typography (curly quotes, ellipsis...)
 * - GeSHi: Adds syntax highlighting to code
 * - dot: Converts Dot diagrams to SVG and VML
 *
 * See http://www.bitstorm.org/weblog/2012-8/Beautify_Markdown_SmartyPants_GeSHi_and_Dot_combined.html
 *
 * Git: https://github.com/edwinm/Beautify
 *
 * Copyright 2012 Edwin Martin <edwin@bitstorm.org>
 *
 * License: MIT and GPL
 *
 * Install Graphvis to get Dot support.
 */

/*
 * User config
 *
 * Change the paths below to the actual paths on your OS.
 */
// Download latest version from http://michelf.ca/projects/php-markdown/
require_once "PHP-Markdown-Extra-1.2.5/markdown.php";
// Download latest version from http://sourceforge.net/projects/geshi/files/
require_once "geshi/geshi.php";
// Download latest version from http://daringfireball.net/projects/smartypants/
require_once "SmartyPants/smartypants-typographer.php";

// Full path to dot program and error log
if (substr(strtoupper(PHP_OS),0,3) == "WIN") { // Windows
	define('DOTPATH', '"C:/Program Files (x86)/Graphviz 2.28/bin/dot.exe"');
	define('DOTERRLOGPATH', 'C:/WINDOWS/Temp/dot-errlog.txt');
} else if (PHP_OS == "Darwin") { // Mac OS X
	define('DOTPATH', '/opt/local/bin/dot');
	define('DOTERRLOGPATH', '/tmp/dot-errorlog.txt');
} else { // Assume Linux or other UNIX-like OS
	define('DOTPATH', '/usr/bin/dot');
	define('DOTERRLOGPATH', '/tmp/dot-errorlog.txt');
}

/*
 *  Output VML for IE8 and older so they can see graphs?
 * 	false: for IE8 and older, an error message is shown
 *  true:  for IE8 and older, VML is generated
 */
define('OUTPUTVML', false);




/**
 * @param $s string Input string
 * @return string HTML string
 */
function beautify($s) {
    $offset = 0;
    $result = '';
	// Split input in code and text parts
    $n = preg_match_all('|((\r?\n~~~+)\s*([a-z0-9_-]*)\r?\n)(.*?)\2\r?\n|s', $s, $matches, PREG_OFFSET_CAPTURE);
    for($i = 0; $i < $n; $i++) {
        $md = substr($s, $offset, $matches[4][$i][1] - $offset - strlen($matches[1][$i][0]));
        $result .= SmartyPants(Markdown($md));
        $code = html_entity_decode(trim($matches[4][$i][0]));
        $language = $matches[3][$i][0];
        if ($language == "dot-view") {
                $code = preg_replace("/{/s", "{\n\rgraph [bgcolor=transparent];", $code); // Remove background rectangle
                $descriptorspec = array(
                   0 => array("pipe", "r"),
                   1 => array("pipe", "w"),
                   2 => array("file", DOTERRLOGPATH, "w")
                );
                $proc = proc_open(DOTPATH." -Tsvg", $descriptorspec, $pipes);
                if (is_resource($proc)) {
                    fwrite($pipes[0], $code);
                    fclose($pipes[0]);
                    $svg = stream_get_contents($pipes[1]);
                    fclose($pipes[1]);
                    proc_close($proc);
                    $svg = preg_replace("/.*<svg/s", "<svg", $svg); // Remove <?xml and <!doctype...
                    $svg = preg_replace("/id=\"(.*?)\"/s", "id=\"$1_$i\"", $svg); // Prevent duplicate id's
                    if (OUTPUTVML) {
                        $proc = proc_open(DOTPATH." -Tvml", $descriptorspec, $pipes);
                        fwrite($pipes[0], $code);
                        fclose($pipes[0]);
                        $vml = stream_get_contents($pipes[1]);
                        fclose($pipes[1]);
                        proc_close($proc);
                        $vml = preg_replace("/<!--.*?-->/s", "", $vml); // Remove comments in favor of conditional comments
                    } else {
                        $vml = "<p>SVG is not supported by your browser</p>";
                    }
                    $out = "<div class=\"beautify-graph\"><!--[if gt IE 8]>-->$svg<!--<![endif]--><!--[if lte IE 8]>$vml<![endif]--></div>\r\n";
                    $result .= $out;
                }
        } else {
            if (!$language) {
                $language = 'text';
            }
            $geshi = new GeSHi($code, $language);
            // Optionally enable GeSHi-features:
            // $geshi->enable_classes();
            // $geshi->enable_line_numbers(GESHI_NORMAL_LINE_NUMBERS);
            $result .= $geshi->parse_code();
        }
        $offset = $matches[4][$i][1] + strlen($matches[4][$i][0]) + strlen($matches[2][$i][0]);
    }
    $result .= SmartyPants(Markdown(substr($s, $offset)));

    return $result;
}