<?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_Session

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

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

 * @version    $Id: Abstract.php 20096 2010-01-06 02:05:09Z bkarwin $

 * @since      Preview Release 0.2

 */

/**

 * Zend_Session_Abstract

 *

 * @category   Zend

 * @package    Zend_Session

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

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

 */

abstract class Zend_Session_Abstract

{

    /**

     * Whether or not session permits writing (modification of $_SESSION[])

     *

     * @var bool

     */

    protected static $_writable = false;

    /**

     * Whether or not session permits reading (reading data in $_SESSION[])

     *

     * @var bool

     */

    protected static $_readable = false;

    /**

     * Since expiring data is handled at startup to avoid __destruct difficulties,

     * the data that will be expiring at end of this request is held here

     *

     * @var array

     */

    protected static $_expiringData = array();

    /**

     * Error message thrown when an action requires modification,

     * but current Zend_Session has been marked as read-only.

     */

    const _THROW_NOT_WRITABLE_MSG = 'Zend_Session is currently marked as read-only.';

    /**

     * Error message thrown when an action requires reading session data,

     * but current Zend_Session is not marked as readable.

     */

    const _THROW_NOT_READABLE_MSG = 'Zend_Session is not marked as readable.';

    /**

     * namespaceIsset() - check to see if a namespace or a variable within a namespace is set

     *

     * @param  string $namespace

     * @param  string $name

     * @return bool

     */

    protected static function _namespaceIsset($namespace, $name = null)

    {

        if (self::$_readable === false) {

            /**

             * @see Zend_Session_Exception

             */

            require_once 'Zend/Session/Exception.php';

            throw new Zend_Session_Exception(self::_THROW_NOT_READABLE_MSG);

        }

        if ($name === null) {

            return ( isset($_SESSION[$namespace]) || isset(self::$_expiringData[$namespace]) );

        } else {

            return ( isset($_SESSION[$namespace][$name]) || isset(self::$_expiringData[$namespace][$name]) );

        }

    }

    /**

     * namespaceUnset() - unset a namespace or a variable within a namespace

     *

     * @param  string $namespace

     * @param  string $name

     * @throws Zend_Session_Exception

     * @return void

     */

    protected static function _namespaceUnset($namespace, $name = null)

    {

        if (self::$_writable === false) {

            /**

             * @see Zend_Session_Exception

             */

            require_once 'Zend/Session/Exception.php';

            throw new Zend_Session_Exception(self::_THROW_NOT_WRITABLE_MSG);

        }

        $name = (string) $name;

        // check to see if the api wanted to remove a var from a namespace or a namespace

        if ($name === '') {

            unset($_SESSION[$namespace]);

            unset(self::$_expiringData[$namespace]);

        } else {

            unset($_SESSION[$namespace][$name]);

            unset(self::$_expiringData[$namespace]);

        }

        // if we remove the last value, remove namespace.

        if (empty($_SESSION[$namespace])) {

            unset($_SESSION[$namespace]);

        }

    }

    /**

     * namespaceGet() - Get $name variable from $namespace, returning by reference.

     *

     * @param  string $namespace

     * @param  string $name

     * @return mixed

     */

    protected static function & _namespaceGet($namespace, $name = null)

    {

        if (self::$_readable === false) {

            /**

             * @see Zend_Session_Exception

             */

            require_once 'Zend/Session/Exception.php';

            throw new Zend_Session_Exception(self::_THROW_NOT_READABLE_MSG);

        }

        if ($name === null) {

            if (isset($_SESSION[$namespace])) { // check session first for data requested

                return $_SESSION[$namespace];

            } elseif (isset(self::$_expiringData[$namespace])) { // check expiring data for data reqeusted

                return self::$_expiringData[$namespace];

            } else {

                return $_SESSION[$namespace]; // satisfy return by reference

            }

        } else {

            if (isset($_SESSION[$namespace][$name])) { // check session first

                return $_SESSION[$namespace][$name];

            } elseif (isset(self::$_expiringData[$namespace][$name])) { // check expiring data

                return self::$_expiringData[$namespace][$name];

            } else {

                return $_SESSION[$namespace][$name]; // satisfy return by reference

            }

        }

    }

    /**

     * namespaceGetAll() - Get an array containing $namespace, including expiring data.

     *

     * @param string $namespace

     * @param string $name

     * @return mixed

     */

    protected static function _namespaceGetAll($namespace)

    {

        $currentData  = (isset($_SESSION[$namespace]) && is_array($_SESSION[$namespace])) ?

            $_SESSION[$namespace] : array();

        $expiringData = (isset(self::$_expiringData[$namespace]) && is_array(self::$_expiringData[$namespace])) ?

            self::$_expiringData[$namespace] : array();

        return array_merge($currentData, $expiringData);

    }

}