htmlpurifier/library/HTMLPurifier/ChildDef/Chameleon.php

<?php

/**
 * Definition that uses different definitions depending on context.
 * 
 * The del and ins tags are notable because they allow different types of
 * elements depending on whether or not they're in a block or inline context.
 * Chameleon allows this behavior to happen by using two different
 * definitions depending on context.  While this somewhat generalized,
 * it is specifically intended for those two tags.
 */
class HTMLPurifier_ChildDef_Chameleon extends HTMLPurifier_ChildDef
{
    
    /**
     * Instance of the definition object to use when inline. Usually stricter.
     */
    public $inline;
    
    /**
     * Instance of the definition object to use when block.
     */
    public $block;
    
    public $type = 'chameleon';
    
    /**
     * @param $inline List of elements to allow when inline.
     * @param $block List of elements to allow when block.
     */
    public function __construct($inline, $block) {
        $this->inline = new HTMLPurifier_ChildDef_Optional($inline);
        $this->block  = new HTMLPurifier_ChildDef_Optional($block);
        $this->elements = $this->block->elements;
    }
    
    public function validateChildren($tokens_of_children, $config, $context) {
        if ($context->get('IsInline') === false) {
            return $this->block->validateChildren(
                $tokens_of_children, $config, $context);
        } else {
            return $this->inline->validateChildren(
                $tokens_of_children, $config, $context);
        }
    }
}