<?php

/**
 * Generic pre-transform that converts an attribute with a fixed number of
 * values (enumerated) to CSS.
 */
class HTMLPurifier_AttrTransform_EnumToCSS extends HTMLPurifier_AttrTransform {
	/**
	 * Name of attribute to transform from.
	 * @type string
	 */
	protected $attr;
	
	/**
	 * Lookup array of attribute values to CSS.
	 * @type array
	 */
	protected $enumToCSS = array ();
	
	/**
	 * Case sensitivity of the matching.
	 * @type bool
	 * @warning Currently can only be guaranteed to work with ASCII
	 * values.
	 */
	protected $caseSensitive = false;
	
	/**
	 *
	 * @param string $attr
	 *        	Attribute name to transform from
	 * @param array $enum_to_css
	 *        	Lookup array of attribute values to CSS
	 * @param bool $case_sensitive
	 *        	Case sensitivity indicator, default false
	 */
	public function __construct($attr, $enum_to_css, $case_sensitive = false) {
		$this->attr = $attr;
		$this->enumToCSS = $enum_to_css;
		$this->caseSensitive = ( bool ) $case_sensitive;
	}
	
	/**
	 *
	 * @param array $attr        	
	 * @param HTMLPurifier_Config $config        	
	 * @param HTMLPurifier_Context $context        	
	 * @return array
	 */
	public function transform($attr, $config, $context) {
		if (! isset ( $attr [$this->attr] )) {
			return $attr;
		}
		
		$value = trim ( $attr [$this->attr] );
		unset ( $attr [$this->attr] );
		
		if (! $this->caseSensitive) {
			$value = strtolower ( $value );
		}
		
		if (! isset ( $this->enumToCSS [$value] )) {
			return $attr;
		}
		$this->prependCSS ( $attr, $this->enumToCSS [$value] );
		return $attr;
	}
}

// vim: et sw=4 sts=4