LazyObjectStorage.php

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<?php
/***************************************************************
 *  Copyright notice
 *
 *  (c) 2009 Jochen Rau <jochen.rau@typoplanet.de>
 *  All rights reserved
 *
 *  This class is a backport of the corresponding class of FLOW3.
 *  All credits go to the v5 team.
 *
 *  This script is part of the TYPO3 project. The TYPO3 project is
 *  free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  The GNU General Public License can be found at
 *  http://www.gnu.org/copyleft/gpl.html.
 *
 *  This script is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  This copyright notice MUST APPEAR in all copies of the script!
 ***************************************************************/

/**
 * A proxy that can replace any object and replaces itself in it's parent on
 * first access (call, get, set, isset, unset).
 *
 * @package Extbase
 * @subpackage Persistence
 * @version $Id$
 */
class Tx_Extbase_Persistence_LazyObjectStorage extends Tx_Extbase_Persistence_ObjectStorage implements Tx_Extbase_Persistence_LoadingStrategyInterface {

    /**
     * This field is only needed to make debugging easier:
     * If you call current() on a class that implements Iterator, PHP will return the first field of the object
     * instead of calling the current() method of the interface.
     * We use this unusual behavior of PHP to return the warning below in this case.
     *
     * @var string
     */
    private $warning = 'You should never see this warning. If you do, you probably used PHP array functions like current() on the Tx_Extbase_Persistence_LazyObjectStorage. To retrieve the first result, you can use the getFirst() method.';

    /**
     * @var Tx_Extbase_Persistence_DataMapper
     */
    protected $dataMapper;

    /**
     * The object this property is contained in.
     *
     * @var object
     */
    protected $parentObject;

    /**
     * The name of the property represented by this proxy.
     *
     * @var string
     */
    protected $propertyName;

    /**
     * The raw field value.
     *
     * @var mixed
     */
    protected $fieldValue;

    /**
     *
     * @var bool
     */
    protected $isInitialized = FALSE;

    /**
     * Returns the state of the initialization
     *
     * @return void
     */
    public function isInitialized() {
        return $this->isInitialized;
    }
    
    /**
     * Constructs this proxy instance.
     *
     * @param object $parentObject The object instance this proxy is part of
     * @param string $propertyName The name of the proxied property in it's parent
     * @param mixed $fieldValue The raw field value.
     */
    public function __construct($parentObject, $propertyName, $fieldValue) {
        $this->parentObject = $parentObject;
        $this->propertyName = $propertyName;
        $this->fieldValue = $fieldValue;
    }

    /**
     * Injects the DataMapper to map nodes to objects
     *
     * @param Tx_Extbase_Persistence_Mapper_DataMapper $dataMapper
     * @return void
     */
    public function injectDataMapper(Tx_Extbase_Persistence_Mapper_DataMapper $dataMapper) {
        $this->dataMapper = $dataMapper;
    }

    /**
     * This is a function lazy load implementation. 
     *
     * @return void
     */
    protected function initialize() {
        if (!$this->isInitialized) {
            $this->isInitialized = TRUE;

            $objects = $this->dataMapper->fetchRelated($this->parentObject, $this->propertyName, $this->fieldValue, FALSE);
            foreach ($objects as $object) {
                parent::attach($object);
            }
            $this->_memorizeCleanState();
            $this->parentObject->_memorizeCleanState($this->propertyName);
        }
    }
        
    // Delegation to the ObjectStorage methods below

    /**
     * @see Tx_Extbase_Persistence_ObjectStorage::addAll
     */
    public function addAll($storage) {
        $this->initialize();
        parent::addAll($storage);
    }

    /**
     * @see Tx_Extbase_Persistence_ObjectStorage::attach
     */
    public function attach($object, $data = NULL) {
        $this->initialize();
        parent::attach($object, $data);
    }

    /**
     * @see Tx_Extbase_Persistence_ObjectStorage::contains
     */
    public function contains($object) {
        $this->initialize();
        return parent::contains($object);
    }

    /**
     * Counts the elements in the storage array
     *
     * @return int The number of elements in the ObjectStorage
     */
    public function count() {
        $columnMap = $this->dataMapper->getDataMap(get_class($this->parentObject))->getColumnMap($this->propertyName);
        $numberOfElements = NULL;
        if ($columnMap->getTypeOfRelation() === Tx_Extbase_Persistence_Mapper_ColumnMap::RELATION_HAS_MANY) {
            $numberOfElements = $this->dataMapper->countRelated($this->parentObject, $this->propertyName, $this->fieldValue);
        } else {
            $this->initialize();
            $numberOfElements = count($this->storage);          
        }
        if (is_null($numberOfElements)) {
            throw new Tx_Extbase_Persistence_Exception('The number of elements could not be determined.', 1252514486);
        }
        return $numberOfElements;
    }

    /**
     * @see Tx_Extbase_Persistence_ObjectStorage::current
     */
    public function current() {
        $this->initialize();
        return parent::current();
    }

    /**
     * @see Tx_Extbase_Persistence_ObjectStorage::detach
     */
    public function detach($object) {
        $this->initialize();
        parent::detach($object);
    }

    /**
     * @see Tx_Extbase_Persistence_ObjectStorage::key
     */
    public function key() {
        $this->initialize();
        return parent::key();
    }

    /**
     * @see Tx_Extbase_Persistence_ObjectStorage::next
     */
    public function next() {
        $this->initialize();
        parent::next();
    }

    /**
     * @see Tx_Extbase_Persistence_ObjectStorage::offsetExists
     */
    public function offsetExists($object) {
        $this->initialize();
        return parent::offsetExists($object);
    }

    /**
     * @see Tx_Extbase_Persistence_ObjectStorage::offsetGet
     */
    public function offsetGet($object) {
        $this->initialize();
        return parent::offsetGet($object);
    }

    /**
     * @see Tx_Extbase_Persistence_ObjectStorage::offsetSet
     */
    public function offsetSet($object , $info) {
        $this->initialize();
        parent::offsetSet($object, $info);
    }

    /**
     * @see Tx_Extbase_Persistence_ObjectStorage::offsetUnset
     */
    public function offsetUnset($object) {
        $this->initialize();
        parent::offsetUnset($object);
    }

    /**
     * @see Tx_Extbase_Persistence_ObjectStorage::removeAll
     */
    public function removeAll($storage) {
        $this->initialize();
        parent::removeAll($storage);
    }

    /**
     * @see Tx_Extbase_Persistence_ObjectStorage::rewind
     */
    public function rewind() {
        $this->initialize();
        parent::rewind();
    }

    /**
     * @see Tx_Extbase_Persistence_ObjectStorage::valid
     */
    public function valid() {
        $this->initialize();
        return parent::valid();
    }
    
    /**
     * @see Tx_Extbase_Persistence_ObjectStorage::toArray
     */
    public function toArray() {
        $this->initialize();
        return parent::toArray();
    }
        
}
?>