/common/libraries/plugin/htmlpurifier/library/HTMLPurifier/EntityParser.php

<?php



// if want to implement error collecting here, we'll need to use some sort

// of global data (probably trigger_error) because it's impossible to pass

// $config or $context to the callback functions.





/**

 * Handles referencing and derefencing character entities

 */

class HTMLPurifier_EntityParser

{

    

    /**

     * Reference to entity lookup table.

     */

    protected $_entity_lookup;

    

    /**

     * Callback regex string for parsing entities.

     */

    protected $_substituteEntitiesRegex = '/&(?:[#]x([a-fA-F0-9]+)|[#]0*(\d+)|([A-Za-z_:][A-Za-z0-9.\-_:]*));?/';

    //     1. hex             2. dec      3. string (XML style)

    



    /**

     * Decimal to parsed string conversion table for special entities.

     */

    protected $_special_dec2str = array(34 => '"', 38 => '&', 39 => "'", 60 => '<', 62 => '>');

    

    /**

     * Stripped entity names to decimal conversion table for special entities.

     */

    protected $_special_ent2dec = array('quot' => 34, 'amp' => 38, 'lt' => 60, 'gt' => 62);



    /**

     * Substitutes non-special entities with their parsed equivalents. Since

     * running this whenever you have parsed character is t3h 5uck, we run

     * it before everything else.

     *

     * @param $string String to have non-special entities parsed.

     * @returns Parsed string.

     */

    public function substituteNonSpecialEntities($string)

    {

        // it will try to detect missing semicolons, but don't rely on it

        return preg_replace_callback($this->_substituteEntitiesRegex, array($this, 'nonSpecialEntityCallback'), $string);

    }



    /**

     * Callback function for substituteNonSpecialEntities() that does the work.

     *

     * @param $matches  PCRE matches array, with 0 the entire match, and

     * either index 1, 2 or 3 set with a hex value, dec value,

     * or string (respectively).

     * @returns Replacement string.

     */

    

    protected function nonSpecialEntityCallback($matches)

    {

        // replaces all but big five

        $entity = $matches[0];

        $is_num = (@$matches[0][1] === '#');

        if ($is_num)

        {

            $is_hex = (@$entity[2] === 'x');

            $code = $is_hex ? hexdec($matches[1]) : (int) $matches[2];

            

            // abort for special characters

            if (isset($this->_special_dec2str[$code]))

                return $entity;

            

            return HTMLPurifier_Encoder :: unichr($code);

        }

        else

        {

            if (isset($this->_special_ent2dec[$matches[3]]))

                return $entity;

            if (! $this->_entity_lookup)

            {

                $this->_entity_lookup = HTMLPurifier_EntityLookup :: instance();

            }

            if (isset($this->_entity_lookup->table[$matches[3]]))

            {

                return $this->_entity_lookup->table[$matches[3]];

            }

            else

            {

                return $entity;

            }

        }

    }



    /**

     * Substitutes only special entities with their parsed equivalents.

     *

     * @notice We try to avoid calling this function because otherwise, it

     * would have to be called a lot (for every parsed section).

     *

     * @param $string String to have non-special entities parsed.

     * @returns Parsed string.

     */

    public function substituteSpecialEntities($string)

    {

        return preg_replace_callback($this->_substituteEntitiesRegex, array($this, 'specialEntityCallback'), $string);

    }



    /**

     * Callback function for substituteSpecialEntities() that does the work.

     *

     * This callback has same syntax as nonSpecialEntityCallback().

     *

     * @param $matches  PCRE-style matches array, with 0 the entire match, and

     * either index 1, 2 or 3 set with a hex value, dec value,

     * or string (respectively).

     * @returns Replacement string.

     */

    protected function specialEntityCallback($matches)

    {

        $entity = $matches[0];

        $is_num = (@$matches[0][1] === '#');

        if ($is_num)

        {

            $is_hex = (@$entity[2] === 'x');

            $int = $is_hex ? hexdec($matches[1]) : (int) $matches[2];

            return isset($this->_special_dec2str[$int]) ? $this->_special_dec2str[$int] : $entity;

        }

        else

        {

            return isset($this->_special_ent2dec[$matches[3]]) ? $this->_special_ent2dec[$matches[3]] : $entity;

        }

    }



}



// vim: et sw=4 sts=4