<?php

/**
 * Validates the HTML type length (not to be confused with CSS's length).
 *
 * This accepts integer pixels or percentages as lengths for certain
 * HTML attributes.
 */
class HTMLPurifier_AttrDef_HTML_Length extends HTMLPurifier_AttrDef_HTML_Pixels {
	
	/**
	 *
	 * @param string $string        	
	 * @param HTMLPurifier_Config $config        	
	 * @param HTMLPurifier_Context $context        	
	 * @return bool|string
	 */
	public function validate($string, $config, $context) {
		$string = trim ( $string );
		if ($string === '') {
			return false;
		}
		
		$parent_result = parent::validate ( $string, $config, $context );
		if ($parent_result !== false) {
			return $parent_result;
		}
		
		$length = strlen ( $string );
		$last_char = $string [$length - 1];
		
		if ($last_char !== '%') {
			return false;
		}
		
		$points = substr ( $string, 0, $length - 1 );
		
		if (! is_numeric ( $points )) {
			return false;
		}
		
		$points = ( int ) $points;
		
		if ($points < 0) {
			return '0%';
		}
		if ($points > 100) {
			return '100%';
		}
		return (( string ) $points) . '%';
	}
}

// vim: et sw=4 sts=4