highlight_php.inc.php

<?php
/**
 * PHPLighter
 *
 * A PHP syntax highlighting engine the utilizes token_get_all() to produce a
 * level of syntax highlighting that rivals any modern editor. No more barebone
 * generic syntax highlighting!
 *
 * NOTICE OF LICENSE
 *
 * Licensed under the Open Software License version 3.0
 *
 * This source file is subject to the Open Software License (OSL 3.0) that is
 * bundled with this package in the file LICENSE. It is also available through
 * the world wide web at this URL:
 *
 * http://opensource.org/licenses/OSL-3.0
 *
 * @package phplighter
 * @author Brandon Wamboldt <brandon.wamboldt@gmail.com>
 * @license http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
 * @link http://brandonwamboldt.ca/phplighter
 * @version 1.0.12
 */

/**
 * The main PHPLighter class
 *
 * @see PHPLighter::highlight()
 *
 * @author Brandon Wamboldt <brandon.wamboldt@gmail.com>
 * @since 1.0.0
 */
class PHPLighter
{
	/**
	 * Only basic classes will be added, for builtin tokens (No C_* classes)
	 *
	 * @since 1.0.8
	 * @var int
	 */
	const BASIC_HIGHLIGHTING = 1;

	/**
	 * PHPDoc tags such as @since, @access and @var will not be given tags
	 *
	 * @since 1.0.8
	 * @var int
	 */
	const NO_TOKENIZE_DOC_TAGS = 2;

	/**
	 * Links/URLs in comments will not be converted into HTML links
	 *
	 * @since 1.0.8
	 * @var int
	 */
	const NO_LINKIFY_LINKS = 4;

	/**
	 * E-mail addresses in comments will not be converted to mailto: links
	 *
	 * @since 1.0.8
	 * @var int
	 */
	const NO_LINKIFY_EMAILS = 8;

	/**
	 * An array of builtin functions (Functions included in a PHP extension)
	 *
	 * @access protected
	 * @since 1.0.0
	 * @static
	 * @var array
	 */
	protected static $builtin_functions = NULL;

	/**
	 * Contains a list of PHPDoc tags separated by a | for use in a regex
	 *
	 * PHPDocumentor tags are placed in docblock comments (Comments that start
	 * with /**), and are prefixed with an @ symbol.
	 *
	 * @link http://www.phpdoc.org/docs/latest/for-users/list-of-tags.html
	 *
	 * @access protected
	 * @since 1.0.0
	 * @var string
	 */
	protected static $phpdoc_tags = 'abstract|access|author|category|copyright|deprecated|example|final|filesource|global|ignore|internal|license|link|method|name|package|param|property|return|see|since|static|staticvar|subpacakage|throws|todo|tutorial|uses|var|version';

	/**
	 * Contains an array of PHP Magic Methods
	 *
	 * @link http://php.net/manual/en/language.oop5.magic.php
	 *
	 * @access protected
	 * @since 1.0.0
	 * @var array
	 */
	protected static $magic_methods = array(
		'__sleep',
		'__wakeup',
		'__construct',
		'__toString',
		'__destruct',
		'__invoke',
		'__set_state',
		'__call',
		'__callStatic',
		'__get',
		'__set',
		'__isset',
		'__unset',
		'__clone'
	);

	/**
	 * Class options
	 *
	 * @access protected
	 * @since 1.0.0
	 * @var integer
	 */
	protected $options = 0;

	/**
	 * The original PHP source code to highlight
	 *
	 * @access protected
	 * @since 1.0.0
	 * @var string
	 */
	protected $source = '';

	/**
	 * An array of tokens, generated by token_get_all() usign the original PHP
	 * source code passed to us
	 *
	 * @access protected
	 * @since 1.0.0
	 * @var array
	 */
	protected $tokens = array();

	/**
	 * Sets the source code to highlight and the options to apply
	 *
	 * @param string $source The PHP code to be highlighted. This should include the opening tag
	 * @param int $options optional The options to apply when highlighting the source code
	 *
	 * @access public
	 * @since 1.0.0
	 */
	public function __construct( $source, $options = 0 )
	{
		$this->options = $options;
		$this->source = $source;

		$this->get_builtin_functions();
		$this->tokenize();
	}

	/**
	 * Highlights the given PHP and returns it as a string with HTML tags
	 *
	 * @return string
	 *
	 * @access public
	 * @since 1.0.0
	 */
	public function parse()
	{
		// Basic parsing mode?
		if ( $this->options & self::BASIC_HIGHLIGHTING ) {
			return $this->basic_parse();
		}

		$in_namespace = FALSE;
		$in_class     = FALSE;
		$in_string    = FALSE;
		$output       = '';

		// Go through each token and make it into a tag
		foreach ( $this->tokens as $i => $token ) {

			// Certain tokens such as ; are returned by themselves, everything else is returned as
			// an array with three elements
			if ( is_array( $token ) ) {

				// So we don't have to call these functions all over
				$identifier = $token[0];
				$token_name = token_name( $token[0] );
				$token      = htmlspecialchars( $token[1] );

				// Don't enclose whitespace in a <span> tag, it gets excessive
				if ( $identifier === T_WHITESPACE ) {
					$output .= $token;
				}

				// Special handling for docblocks to deal with docblock tags, links and email links
				else if ( $identifier === T_DOC_COMMENT ) {

					if ( ! ( $this->options & self::NO_TOKENIZE_DOC_TAGS ) ) {
						$token = preg_replace( '/(\@(' . self::$phpdoc_tags . '))(\s)/i', '<span class="C_DOCBLOCK_TAG">\1</span>\3', $token );
					}

					if ( ! ( $this->options & self::NO_LINKIFY_LINKS ) ) {
						$token = preg_replace( '/(http\:\/\/[A-Za-z0-9\.\/\-\_\~\#\?\=\&\!\%]*)/i', '<a href="\1" class="C_DOCBLOCK_LINK">\1</a>', $token );
					}

					if ( ! ( $this->options & self::NO_LINKIFY_EMAILS ) ) {
						$token = preg_replace( '/\&lt\;([A-Za-z0-9].*?@.*?)\&gt\;/i', '&lt;<a href="mailto:\1" class="C_DOCBLOCK_LINK">\1</a>&gt;', $token );
					}

					$output .= '<span class="' . $token_name . '">' . $token . '</span>';
				}

				// Special handling for comments to deal with links and email links
				else if ( $identifier === T_COMMENT ) {

					if ( ! ( $this->options & self::NO_LINKIFY_LINKS ) ) {
						$token = preg_replace( '/(http\:\/\/[A-Za-z0-9\.\/\-\_\~\#\?\=\&\!\%]*)/i', '<a href="\1" class="C_COMMENT_LINK">\1</a>', $token );
					}

					if ( ! ( $this->options & self::NO_LINKIFY_EMAILS ) ) {
						$token = preg_replace( '/\&lt\;([A-Za-z0-9].*?@.*?)\&gt\;/i', '&lt;<a href="mailto:\1" class="C_COMMENT_LINK">\1</a>&gt;', $token );
					}

					$output .= '<span class="' . $token_name . '">' . $token . '</span>';
				}

				// The 'self' keyword is just tokenized as a string, we give it a special identifier
				else if ( $identifier === T_STRING && strtolower( $token ) == 'self' ) {
					$output .= '<span class="T_STRING C_SELF">' . $token . '</span>';
				}

				// The 'null' keyword is just tokenized as a string, we give it a special identifier
				else if ( $identifier === T_STRING && strtolower( $token ) == 'null' ) {
					$output .= '<span class="T_STRING C_NULL">' . $token . '</span>';
				}

				// The 'true' keyword is just tokenized as a string, we give it a special identifier
				else if ( $identifier === T_STRING && strtolower( $token ) == 'true' ) {
					$output .= '<span class="T_STRING C_TRUE">' . $token . '</span>';
				}

				// The 'false' keyword is just tokenized as a string, we give it a special identifier
				else if ( $identifier === T_STRING && strtolower( $token ) == 'false' ) {
					$output .= '<span class="T_STRING C_FALSE">' . $token . '</span>';
				}

				// Identify class method calls, like $this->myMethod(), not 100% successful
				else if ( $identifier === T_STRING && $this->prev_token( $i ) === T_OBJECT_OPERATOR && $this->next_token( $i ) === '(' ) {
					$output .= '<span class="T_STRING C_METHOD_CALL">' . $token . '</span>';
				}

				// Idenfy classnames
				else if ( $identifier === T_STRING && $this->prev_token( $i ) === T_CLASS ) {
					$output .= '<span class="T_STRING C_CLASSNAME">' . $token . '</span>';
				}

				else if ( $identifier === T_STRING && $this->prev_token( $i ) === T_EXTENDS ) {
					$output .= '<span class="T_STRING C_EXTENDS_CLASS">' . $token . '</span>';
				}

				else if ( $identifier === T_STRING && $this->prev_token( $i ) === T_IMPLEMENTS ) {
					$output .= '<span class="T_STRING C_IMPLEMENTS_CLASS">' . $token . '</span>';
				}

				else if ( $identifier === T_STRING && $this->prev_token( $i ) === T_NEW ) {
					$output .= '<span class="T_STRING C_CLASSNAME_REF">' . $token . '</span>';
				}

				else if ( $identifier === T_STRING && $this->next_token( $i ) === T_VARIABLE ) {
					$output .= '<span class="T_STRING C_PARAMETER_TYPEHINT">' . $token . '</span>';
				}

				// Class properties ($var->property)
				else if ( $identifier === T_STRING && $this->prev_token( $i ) === T_OBJECT_OPERATOR && $this->next_token( $i ) !== '(' ) {
					$output .= '<span class="T_STRING C_OBJECT_PROPERTY">' . $token . '</span>';
				}

				// PHP Magic Method definitions
				else if ( $identifier === T_STRING && in_array( $token, self::$magic_methods ) ) {
					$output .= '<span class="T_STRING C_MAGIC_METHOD">' . $token . '</span>';
				}

				// Namespace declarations
				else if ( $identifier === T_STRING && ( $this->prev_token( $i ) === T_NAMESPACE || $this->prev_token( $i ) === T_USE ) ) {
					$output .= '<span class="C_NAMESPACE"><span class="T_STRING">' . $token . '</span>';
					$in_namespace = TRUE;
				}

				// Function names
				else if ( $identifier === T_STRING && $this->prev_token( $i ) === T_FUNCTION ) {
					$output .= '<span class="T_STRING C_FUNCTION_NAME">' . $token . '</span>';
				}

				// Builtin Functions
				else if ( $identifier === T_STRING && in_array( $token, PHPLighter::$builtin_functions ) && $this->prev_token( $i ) !== T_FUNCTION ) {
					$output .= '<span class="T_STRING C_BUILTIN_FUNCTION">' . $token . '</span>';
				}

				// Special string handling
				else if ( $identifier === T_CONSTANT_ENCAPSED_STRING || $identifier === T_ENCAPSED_AND_WHITESPACE ) {
					$output .= '<span class="' . $token_name . '">' . preg_replace( '`(\\\[^ ])`', '<span class="C_DOUBLE_BACKSLASH">\1</span>', $token ) . '</span>';
				}

				// Start heredocs
				else if ( $identifier === T_START_HEREDOC ) {
					$output .= '<span class="T_START_HEREDOC"><span class="C_HEREDOC_ARROWS">&lt;&lt;&lt;</span>' .  str_replace( '&lt;&lt;&lt;', '', $token )  . '</span>';
				}

				// All other token
				else {
					$output .= '<span class="' . $token_name . '">' . $token . '</span>';
				}
			} else {

				// If we are in a namespace string and encounter a semicolon, end the namespace string
				if ( $token == ';' && $in_namespace ) {
					$output .= '</span><span class="C_SEMICOLON">;</span>';
					$in_namespace = FALSE;
				}

				// Give semicolons a name
				else if ( $token == ';' ) {
					$output .= '<span class="C_SEMICOLON">;</span>';
				}

				// Give assignment operators a name
				else if ( $token == '=' ) {
					$output .= '<span class="C_ASSIGNMENT">=</span>';
				}

				// Special handling for double quoted strings which may contain variables
				else if ( $token == '"' ) {
					if ( $in_string ) {
						$output .= '"</span>';
						$in_string = FALSE;
					} else {
						$output .= '<span class="C_VARSTRING">"';
						$in_string = TRUE;
					}
				}

				// All other single character tokens
				else {
					$output .= $token;
				}
			}
		}

		return '<pre class="pretty-php">' . $output . '</pre>';
	}

	/**
	 * Just like parse() but it only uses builtin tokens
	 *
	 * @return string
	 *
	 * @access protected
	 * @since 1.0.0
	 */
	protected function basic_parse()
	{
		$output = '';

		// Go through each token and make it into a tag
		foreach ( $this->tokens as $i => $token ) {
			// Certain tokens such as ; are returned by themselves, everything else is returned as
			// an array with three elements
			if ( is_array( $token ) ) {
				if ( $token[0] !== T_WHITESPACE ) {
					$output .= '<span class="' . token_name( $token[0] ) . '">' . htmlspecialchars( $token[1] ) . '</span>';
				} else {
					$output .= $token[1];
				}
			} else {
				$output .= $token;
			}
		}

		return $output;
	}

	/**
	 * If we haven't already got a list of builtin functions, get them and
	 * store them as a static variable
	 *
	 * @access protected
	 * @since 1.0.0
	 */
	protected function get_builtin_functions()
	{
		if ( PHPLighter::$builtin_functions === NULL ) {
			PHPLighter::$builtin_functions = array();
			$loaded_ext = get_loaded_extensions();

			foreach ( $loaded_ext as $ext ) {
				PHPLighter::$builtin_functions = array_merge( PHPLighter::$builtin_functions, (array) get_extension_funcs( $ext ) );
			}
		}
	}

	/**
	 * Split given source into PHP tokens (PHP 4 >= 4.2.0, PHP 5)
	 *
	 * token_get_all() returns an array of tokens. Some array elements will be
	 * an array themselves, containing the token type, the PHP source for that
	 * token, and the line number that the token occured on. Other elements
	 * will simply be the token itself, such as (, ), [, and ]
	 *
	 * @link http://ca.php.net/manual/en/tokens.php
	 * @link http://ca.php.net/token_get_all
	 * @link http://ca.php.net/manual/en/function.token-name.php
	 *
	 * @access protected
	 * @since 1.0.0
	 */
	protected function tokenize()
	{
		$this->tokens = token_get_all( $this->source );
	}

	/**
	 * Retrieve the next token from the array of tokens
	 *
	 * @param int $position The position in the token array
	 * @param int $modifier The token to get (Defaults to 1, for the next token)
	 * @param bool $significant optional Whether or not to retrieve only significant tokens (Not T_WHITESPACE)
	 * @return int
	 *
	 * @access protected
	 * @since 1.0.0
	 */
	protected function next_token( $position, $modifier = 1, $significant = TRUE )
	{
		// No tokens left
		if ( ! isset( $this->tokens[$position + $modifier] ) ) {
			return 0;
		}

		$token = $this->tokens[$position + $modifier];

		// Return the next significant (Non T_WHITESPACE) token?
		if ( $significant === TRUE ) {

			// If the requested token is a T_WHITESPACE token, call this function again but add 1 to the modifer
			if ( $this->tokens[$position + $modifier][0] === T_WHITESPACE ) {
				$token = $this->next_token( $position, $modifier + 1 );
			} else {
				$token = $this->tokens[$position + $modifier];
			}
		}

		// Return the next token
		if ( is_array( $token ) ) {
			return $token[0];
		}

		return $token;
	}

	/**
	 * Retrieve the previous token from the array of tokens
	 *
	 * @param int $position The position in the token array
	 * @param int $modifier The token to get (Defaults to 1, for the previous token)
	 * @param bool $significant optional Whether or not to retrieve only significant tokens (Not T_WHITESPACE)
	 * @return int
	 *
	 * @access protected
	 * @since 1.0.0
	 */
	protected function prev_token( $position, $modifier = 1, $significant = TRUE )
	{
		// No tokens left
		if ( ! isset( $this->tokens[$position - $modifier] ) ) {
			return 0;
		}

		$token = $this->tokens[$position - $modifier];

		// Return the next significant (Non T_WHITESPACE) token?
		if ( $significant === TRUE ) {

			// If the requested token is a T_WHITESPACE token, call this function again but add 1 to the modifer
			if ( $this->tokens[$position - $modifier][0] === T_WHITESPACE ) {
				$token = $this->prev_token( $position, $modifier + 1 );
			} else {
				$token = $this->tokens[$position - $modifier];
			}
		}

		// Return the next token
		if ( is_array( $token ) ) {
			return $token[0];
		} else {
			return $token;
		}
	}

	/**
	 * Outputs or returns a syntax highlighted version of the given PHP code using
	 * the colors defined in the included stylesheet
	 *
	 * @param string $source The PHP code to be highlighted. This should include the opening tag
	 * @param bool $return optional Set this parameter to TRUE to make this function return the highlighted code
	 * @return string|void
	 *
	 * @access public
	 * @since 1.0.0
	 * @static
	 */
	public static function highlight( $source, $return = FALSE, $options = 0 )
	{
		$p = new PHPLighter( $source, $options );
		$str = $p->parse();

		if ( $return ) {
			return $str;
		}

		echo $str;
	}
}