Due to Google AMP (Accelerated Mobile Pages) , I have been looking for a way to effectively do Syntax Highlighting without Javascript in pure PHP.
I was about to write my own, when I found an older article from phoboslab. Thanks Dominic for saving me some time ;) Its not perfect, but close enough.
A simple Syntax Highlighting Class that does just that. The class was not working with PHP 5.4.x+, as it uses preg_replace() with the /e modifier.
It will not cover all, but its better than nothing :) I will also add a section to my my AMP tweaks article to showcase the integration of Geshi.
Here an updated version using the preg_replace_callback() function.
THE SYNTAX HIGHLIGHT CLASS
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class SyntaxHighlight { static $tokens = array();// This array will be filled from the regexp-callback public static function process($s) { $s = htmlspecialchars($s); // Workaround for escaped backslashes $s = str_replace('\\\\','\\\\<e>', $s); $regexp = array( // Punctuations '/([\-\!\%\^\*\(\)\+\|\~\=`\{\}\[\]\:\"\'<>\?\,\.\/]+)/' => '<span class="P">$1</span>', // Numbers (also look for Hex) '/(?<!\w)( (0x|\#)[\da-f]+| \d+| \d+(px|em|cm|mm|rem|s|\%) )(?!\w)/ix' => '<span class="N">$1</span>', // Make the bold assumption that an // all uppercase word has a special meaning '/(?<!\w|>|\#)( [A-Z_0-9]{2,} )(?!\w)/x' => '<span class="D">$1</span>', // Keywords '/(?<!\w|\$|\%|\@|>)( and|or|xor|for|do|while|foreach|as|return|die|exit|if|then|else| elseif|new|delete|try|throw|catch|finally|class|function|string| array|object|resource|var|bool|boolean|int|integer|float|double| real|string|array|global|const|static|public|private|protected| published|extends|switch|true|false|null|void|this|self|struct| char|signed|unsigned|short|long )(?!\w|=")/ix' => '<span class="K">$1</span>', // PHP/Perl-Style Vars: $var, %var, @var '/(?<!\w)( (\$|\%|\@)(\->|\w)+ )(?!\w)/ix' => '<span class="V">$1</span>' ); $s = preg_replace_callback( '/( \/\*.*?\*\/| \/\/.*?\n| \#.[^a-fA-F0-9]+?\n| \<\!\-\-[\s\S]+\-\-\>| (?<!\\\)".*?(?<!\\\)"| (?<!\\\)\'(.*?)(?<!\\\)\' )/isx' , array('SyntaxHighlight', 'replaceId'),$s); $s = preg_replace(array_keys($regexp), array_values($regexp), $s); // Paste the comments and strings back in again $s = str_replace(array_keys(SyntaxHighlight::$tokens), array_values(SyntaxHighlight::$tokens), $s); // Delete the "Escaped Backslash Workaround Token" (TM) // and replace tabs with four spaces. $s = str_replace(array('<e>', "\t"), array('', ' '), $s); return '<pre>'.$s.'</pre>' ; } // Regexp-Callback to replace every comment or string with a uniqid and save // the matched text in an array // This way, strings and comments will be stripped out and wont be processed // by the other expressions searching for keywords etc. static function replaceId($match) { $id = "##r" . uniqid() . "##"; // String or Comment? if(substr($match[1], 0, 2) == '//' || substr($match[1], 0, 2) == '/*' || substr($match[1], 0, 2) == '##' || substr($match[1], 0, 7) == '<!--') { SyntaxHighlight::$tokens[$id] = '<span class="C">' . $match[1] . '</span>'; } else { SyntaxHighlight::$tokens[$id] = '<span class="S">' . $match[1] . '</span>'; } return $id; } } |
THE CSS
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pre { font-family: 'Courier New', 'Bitstream Vera Sans Mono', 'monospace'; font-size: 9pt; border-top: 1px solid #333; border-bottom: 1px solid #333; padding: 0.4em; color: #fff; } pre span.N{ color:#f2c47f; } /* Numbers */ pre span.S{ color:#42ff00; } /* Strings */ pre span.C{ color:#838383; } /* Comments */ pre span.K{ color:#ff0078; } /* Keywords */ pre span.V{ color:#70d6ff; } /* Vars */ pre span.D{ color:#ff9a5d; } /* Defines */ |
USAGE
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echo SyntaxHighlight::process( $your_code ); |
