<?php

/**

 * Zend Framework

 *

 * LICENSE

 *

 * This source file is subject to the new BSD license that is bundled

 * with this package in the file LICENSE.txt.

 * It is also available through the world-wide-web at this URL:

 * http://framework.zend.com/license/new-bsd

 * If you did not receive a copy of the license and are unable to

 * obtain it through the world-wide-web, please send an email

 * to license@zend.com so we can send you a copy immediately.

 *

 * @category   Zend

 * @package    Zend_Feed

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 */

/**

 * @see Zend_Feed_Element

 */

require_once 'Zend/Feed/Element.php';

/**

 * The Zend_Feed_Abstract class is an abstract class representing feeds.

 *

 * Zend_Feed_Abstract implements two core PHP 5 interfaces: ArrayAccess and

 * Iterator. In both cases the collection being treated as an array is

 * considered to be the entry collection, such that iterating over the

 * feed takes you through each of the feed.s entries.

 *

 * @category   Zend

 * @package    Zend_Feed

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 */

abstract class Zend_Feed_Abstract extends Zend_Feed_Element implements Iterator, Countable

{

    /**

     * Current index on the collection of feed entries for the

     * Iterator implementation.

     *

     * @var integer

     */

    protected $_entryIndex = 0;

    /**

     * Cache of feed entries.

     *

     * @var array

     */

    protected $_entries;

    /**

     * Feed constructor

     *

     * The Zend_Feed_Abstract constructor takes the URI of a feed or a

     * feed represented as a string and loads it as XML.

     *

     * @param  string $uri The full URI of the feed to load, or NULL if not retrieved via HTTP or as an array.

     * @param  string $string The feed as a string, or NULL if retrieved via HTTP or as an array.

     * @param  Zend_Feed_Builder_Interface $builder The feed as a builder instance or NULL if retrieved as a string or via HTTP.

     * @return void

     * @throws Zend_Feed_Exception If loading the feed failed.

     */

    public function __construct($uri = null, $string = null, Zend_Feed_Builder_Interface $builder = null)

    {

        if ($uri !== null) {

            // Retrieve the feed via HTTP

            $client = Zend_Feed::getHttpClient();

            $client->setUri($uri);

            $response = $client->request('GET');

            if ($response->getStatus() !== 200) {

                /**

                 * @see Zend_Feed_Exception

                 */

                require_once 'Zend/Feed/Exception.php';

                throw new Zend_Feed_Exception('Feed failed to load, got response code ' . $response->getStatus() . '; request: ' . $client->getLastRequest() . "\nresponse: " . $response->asString());

            }

            $this->_element = $this->_importFeedFromString($response->getBody());

            $this->__wakeup();

        } elseif ($string !== null) {

            // Retrieve the feed from $string

            $this->_element = $string;

            $this->__wakeup();

        } else {

            // Generate the feed from the array

            $header = $builder->getHeader();

            $this->_element = new DOMDocument('1.0', $header['charset']);

            $root = $this->_mapFeedHeaders($header);

            $this->_mapFeedEntries($root, $builder->getEntries());

            $this->_element = $root;

            $this->_buildEntryCache();

        }

    }

    /**

     * Load the feed as an XML DOMDocument object

     *

     * @return void

     * @throws Zend_Feed_Exception

     */

    public function __wakeup()

    {

        @ini_set('track_errors', 1);

        $doc = new DOMDocument;

        @ini_restore('track_errors');

            // prevent the class to generate an undefined variable notice (ZF-2590)

            if (!isset($php_errormsg)) {

                if (function_exists('xdebug_is_enabled')) {

                    $php_errormsg = '(error message not available, when XDebug is running)';

                } else {

                    $php_errormsg = '(error message not available)';

                }

            }

            /**

             * @see Zend_Feed_Exception

             */

            require_once 'Zend/Feed/Exception.php';

            throw new Zend_Feed_Exception("DOMDocument cannot parse XML: $php_errormsg");

        }

        $this->_element = $doc;

    }

    /**

     * Prepare for serialiation

     *

     * @return array

     */

    public function __sleep()

    {

        $this->_element = $this->saveXML();

        return array('_element');

    }

    /**

     * Cache the individual feed elements so they don't need to be

     * searched for on every operation.

     *

     * @return void

     */

    protected function _buildEntryCache()

    {

        $this->_entries = array();

        foreach ($this->_element->childNodes as $child) {

            if ($child->localName == $this->_entryElementName) {

                $this->_entries[] = $child;

            }

        }

    }

    /**

     * Get the number of entries in this feed object.

     *

     * @return integer Entry count.

     */

    public function count()

    {

        return count($this->_entries);

    }

    /**

     * Required by the Iterator interface.

     *

     * @return void

     */

    public function rewind()

    {

        $this->_entryIndex = 0;

    }

    /**

     * Required by the Iterator interface.

     *

     * @return mixed The current row, or null if no rows.

     */

    public function current()

    {

        return new $this->_entryClassName(

            null,

            $this->_entries[$this->_entryIndex]);

    }

    /**

     * Required by the Iterator interface.

     *

     * @return mixed The current row number (starts at 0), or NULL if no rows

     */

    public function key()

    {

        return $this->_entryIndex;

    }

    /**

     * Required by the Iterator interface.

     *

     * @return mixed The next row, or null if no more rows.

     */

    public function next()

    {

        ++$this->_entryIndex;

    }

    /**

     * Required by the Iterator interface.

     *

     * @return boolean Whether the iteration is valid

     */

    public function valid()

    {

        return 0 <= $this->_entryIndex && $this->_entryIndex < $this->count();

    }

    /**

     * Generate the header of the feed when working in write mode

     *

     * @param  array $array the data to use

     * @return DOMElement root node

     */

    abstract protected function _mapFeedHeaders($array);

    /**

     * Generate the entries of the feed when working in write mode

     *

     * @param  DOMElement $root the root node to use

     * @param  array $array the data to use

     * @return DOMElement root node

     */

    abstract protected function _mapFeedEntries(DOMElement $root, $array);

    /**

     * Send feed to a http client with the correct header

     *

     * @throws Zend_Feed_Exception if headers have already been sent

     * @return void

     */

    abstract public function send();

    /**

     * Import a feed from a string

     *

     * Protects against XXE attack vectors.

     * 

     * @param  string $feed 

     * @return string

     * @throws Zend_Feed_Exception on detection of an XXE vector

     */

    protected function _importFeedFromString($feed)

    {

        if (trim($feed) == '') {

            require_once 'Zend/Feed/Exception.php';

            throw new Zend_Feed_Exception('Remote feed being imported'

            . ' is an Empty string or comes from an empty HTTP response');

        }

            // prevent the class to generate an undefined variable notice (ZF-2590)

            // Build error message

            $error = libxml_get_last_error();

            if ($error && $error->message) {

                $errormsg = "DOMDocument cannot parse XML: {$error->message}";

            } else {

                $errormsg = "DOMDocument cannot parse XML";

            }

            /**

             * @see Zend_Feed_Exception

             */

            require_once 'Zend/Feed/Exception.php';

            throw new Zend_Feed_Exception($errormsg);

        }

        return $doc->saveXML($doc->documentElement);

    }

}