/build/tools/css-compressor/lib/Trim.php

<?php

/**

 * CSS Compressor [VERSION]

 * [DATE]

 * Corey Hart @ http://www.codenothing.com

 */ 



Class CSSCompression_Trim

{

	/**

	 * Trim Patterns

	 *

	 * @class Control: Compression Controller

	 * @param (array) options: Reference to options

	 * @param (regex) rcmark: Marking point when traversing through sheet for comments

	 * @param (regex) rendcomment: Finds the ending comment point

	 * @param (regex) rendquote: Finds the ending quote point

	 * @param (regex) rendsinglequote: Finds the ending single quote point

	 * @param (array) rescape: Array of patterns of groupings that should be escaped

	 * @param (array) trimmings: Stylesheet trimming patterns/replacements

	 * @param (array) escaped: Array of characters that need to be escaped

	 */

	private $Control;

	private $options = array();

	private $rcmark = "/((?<!\\\)\/\*|(?<!\\\)\"|(?<!\\\)')/";

	private $rendcomment = "/\*\//";

	private $rendquote = "/(?<!\\\)\"/";

	private $rendsinglequote = "/(?<!\\\)'/";

	private $rescape = array(

		"/(url\()([^'\"].*?)(\))/is",

		"/((?<!\\\)\")(.*?)((?<!\\\)\")/s",

		"/((?<!\\\)')(.*?)((?<!\\\)')/s",

	);

	private $trimmings = array(

		'patterns' => array(

			"/(?<!\\\)(\s+)?(?<!\\\)([!,{};>\~\+\/])(?<!\\\)(\s+)?/s", // Remove un-needed spaces around special characters

			"/url\((?<!\\\)\"(.*?)(?<!\\\)\"\)/is", // Remove quotes from urls

			"/url\((?<!\\\)'(.*?)(?<!\\\)'\)/is", // Remove single quotes from urls

			"/url\((.*?)\)/is", // Lowercase url wrapper

			"/(?<!\\\);{2,}/", // Remove unecessary semi-colons

			"/(?<!\\\)\s+/s", // Compress all spaces into single space

		),

		'replacements' => array(

			'$2',

			'url($1)',

			'url($1)',

			'url($1)',

			';',

			' ',

		)

	);

	private $escaped = array(

		'search' => array(

			":",

			";",

			"}",

			"{",

			"@",

			"!",

			",",

			">",

			"+",

			"~",

			"/",

			"*",

			".",

			"=",

			"#",

			"\r",

			"\n",

			"\t",

			" ",

		),

		'replace' => array(

			"\\:",

			"\\;",

			"\\}",

			"\\{",

			"\\@",

			"\\!",

			"\\,",

			"\\>",

			"\\+",

			"\\~",

			"\\/",

			"\\*",

			"\\.",

			"\\=",

			"\\#",

			"\\r",

			"\\n",

			"\\t",

			"\\ ",

		),

	);



	/**

	 * Stash a reference to the controller on each instantiation

	 *

	 * @param (class) control: CSSCompression Controller

	 */

	public function __construct( CSSCompression_Control $control ) {

		$this->Control = $control;

		$this->options = &$control->Option->options;

	}



	/**

	 * Central trim handler

	 *

	 * @param (string) css: Stylesheet to trim

	 */

	public function trim( $css ) {

		$css = $this->comments( $css );

		$css = $this->escape( $css );

		$css = $this->strip( $css );

		return $css;

	}



	/**

	 * Does a quick run through the script to remove all comments from the sheet,

	 *

	 * @param (string) css: Stylesheet to trim

	 */

	private function comments( $css ) {

		$pos = 0;

		while ( preg_match( $this->rcmark, $css, $match, PREG_OFFSET_CAPTURE, $pos ) ) {

			switch ( $match[ 1 ][ 0 ] ) {

				// Start of comment block

				case "/*":

					if ( preg_match( $this->rendcomment, $css, $m, PREG_OFFSET_CAPTURE, $match[ 1 ][ 1 ] + 1 ) ) {

						$end = $m[ 0 ][ 1 ] - $match[ 1 ][ 1 ] + strlen( $m[ 0 ][ 0 ] );

						$css = substr_replace( $css, '', $match[ 1 ][ 1 ], $end );

						$pos = $match[ 0 ][ 1 ];

					}

					else {

						$css = substr( $css, 0, $match[ 1 ][ 1 ] );

						break 2;

					}

					break;

				// Start of string

				case "\"":

					if ( preg_match( $this->rendquote, $css, $m, PREG_OFFSET_CAPTURE, $match[ 1 ][ 1 ] + 1 ) ) {

						$pos = $m[ 0 ][ 1 ] + strlen( $m[ 0 ][ 0 ] );

					}

					else {

						break 2;

					}

					break;

				// Start of string

				case "'":

					if ( preg_match( $this->rendsinglequote, $css, $m, PREG_OFFSET_CAPTURE, $match[ 1 ][ 1 ] + 1 ) ) {

						$pos = $m[ 0 ][ 1 ] + strlen( $m[ 0 ][ 0 ] );

					}

					else {

						break 2;

					}

					break;

				// Should have never gotten here

				default:

					break 2;

			}

		}



		return $css;

	}



	/**

	 * Escape out possible splitter characters within urls

	 *

	 * @param (string) css: Full stylesheet

	 */

	private function escape( $css ) {

		foreach ( $this->rescape as $regex ) {

			$start = 0;

			while ( preg_match( $regex, $css, $match, PREG_OFFSET_CAPTURE, $start ) ) {

				$value = $match[ 1 ][ 0 ]

					. str_replace( $this->escaped['search'], $this->escaped['replace'], $match[ 2 ][ 0 ] )

					. $match[ 3 ][ 0 ];

				$css = substr_replace( $css, $value, $match[ 0 ][ 1 ], strlen( $match[ 0 ][ 0 ] ) );

				$start = $match[ 0 ][ 1 ] + strlen( $value ) + 1;

			}

		}



		return $css;

	}



	/**

	 * Runs initial formatting to setup for compression

	 *

	 * @param (string) css: CSS Contents

	 */ 

	private function strip( $css ) {

		// Run replacements

		return trim( preg_replace( $this->trimmings['patterns'], $this->trimmings['replacements'], $css ) );

	}



	/**

	 * Access to private methods for testing

	 *

	 * @param (string) method: Method to be called

	 * @param (array) args: Array of paramters to be passed in

	 */

	public function access( $method, $args ) {

		if ( method_exists( $this, $method ) ) {

			return call_user_func_array( array( $this, $method ), $args );

		}

		else {

			throw new CSSCompression_Exception( "Unknown method in Trim Class - " . $method );

		}

	}

};



?>