Persistence/Generic/LazyObjectStorage.php

<?php

/*
 * This file is part of the TYPO3 CMS project.
 *
 * It is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License, either version 2
 * of the License, or any later version.
 *
 * For the full copyright and license information, please read the
 * LICENSE.txt file that was distributed with this source code.
 *
 * The TYPO3 project - inspiring people to share!
 */

namespace TYPO3\CMS\Extbase\Persistence\Generic;

use TYPO3\CMS\Extbase\DomainObject\DomainObjectInterface;
use TYPO3\CMS\Extbase\Object\ObjectManagerInterface;
use TYPO3\CMS\Extbase\Persistence\Generic\Mapper\ColumnMap;
use TYPO3\CMS\Extbase\Persistence\Generic\Mapper\DataMapper;
use TYPO3\CMS\Extbase\Persistence\ObjectStorage;

/**
 * A proxy that can replace any object and replaces itself in it's parent on
 * first access (call, get, set, isset, unset).
 * @internal only to be used within Extbase, not part of TYPO3 Core API.
 */
class LazyObjectStorage extends ObjectStorage implements 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 TYPO3\\CMS\\Extbase\\Persistence\\Generic\\LazyObjectStorage. To retrieve the first result, you can use the rewind() and current() methods.';

    /**
     * @var DataMapper|null
     */
    protected $dataMapper;

    /**
     * The object this property is contained in.
     *
     * @var \TYPO3\CMS\Extbase\DomainObject\DomainObjectInterface
     */
    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;

    /**
     * @var ObjectManagerInterface
     */
    protected $objectManager;

    /**
     * @param ObjectManagerInterface $objectManager
     */
    public function injectObjectManager(ObjectManagerInterface $objectManager)
    {
        $this->objectManager = $objectManager;
    }

    /**
     * Returns the state of the initialization
     *
     * @return bool
     */
    public function isInitialized()
    {
        return $this->isInitialized;
    }

    /**
     * Constructs this proxy instance.
     *
     * @param DomainObjectInterface $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.
     * @param ?DataMapper $dataMapper
     */
    public function __construct($parentObject, $propertyName, $fieldValue, ?DataMapper $dataMapper = null)
    {
        $this->parentObject = $parentObject;
        $this->propertyName = $propertyName;
        $this->fieldValue = $fieldValue;
        reset($this->storage);
        $this->dataMapper = $dataMapper;
    }

    /**
     * Object initialization called when object is created with ObjectManager, after constructor
     */
    public function initializeObject()
    {
        if (!$this->dataMapper) {
            $this->dataMapper = $this->objectManager->get(DataMapper::class);
        }
    }

    /**
     * This is a function lazy load implementation.
     */
    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);
            }
            $this->_memorizeCleanState();
            if (!$this->isStorageAlreadyMemorizedInParentCleanState()) {
                $this->parentObject->_memorizeCleanState($this->propertyName);
            }
        }
    }

    /**
     * @return bool
     */
    protected function isStorageAlreadyMemorizedInParentCleanState()
    {
        return $this->parentObject->_getCleanProperty($this->propertyName) === $this;
    }

    // Delegation to the ObjectStorage methods below
    /**
     * @param \TYPO3\CMS\Extbase\Persistence\ObjectStorage $storage
     *
     * @see \TYPO3\CMS\Extbase\Persistence\ObjectStorage::addAll
     */
    public function addAll(ObjectStorage $storage)
    {
        $this->initialize();
        parent::addAll($storage);
    }

    /**
     * @param DomainObjectInterface $object The object to add.
     * @param mixed $data The data to associate with the object.
     *
     * @see \TYPO3\CMS\Extbase\Persistence\ObjectStorage::attach
     */
    public function attach($object, $data = null)
    {
        $this->initialize();
        parent::attach($object, $data);
    }

    /**
     * @param DomainObjectInterface $object The object to look for.
     * @return bool
     *
     * @see \TYPO3\CMS\Extbase\Persistence\ObjectStorage::contains
     */
    public function contains($object)
    {
        $this->initialize();
        return parent::contains($object);
    }

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

    /**
     * @return DomainObjectInterface The object at the current iterator position.
     *
     * @see \TYPO3\CMS\Extbase\Persistence\ObjectStorage::current
     */
    public function current()
    {
        $this->initialize();
        return parent::current();
    }

    /**
     * @param DomainObjectInterface $object The object to remove.
     *
     * @see \TYPO3\CMS\Extbase\Persistence\ObjectStorage::detach
     */
    public function detach($object)
    {
        $this->initialize();
        parent::detach($object);
    }

    /**
     * @return string The index corresponding to the position of the iterator.
     *
     * @see \TYPO3\CMS\Extbase\Persistence\ObjectStorage::key
     */
    public function key()
    {
        $this->initialize();
        return parent::key();
    }

    /**
     * @see \TYPO3\CMS\Extbase\Persistence\ObjectStorage::next
     */
    public function next()
    {
        $this->initialize();
        parent::next();
    }

    /**
     * @param DomainObjectInterface $value The object to look for, or the key in the storage.
     * @return bool
     *
     * @see \TYPO3\CMS\Extbase\Persistence\ObjectStorage::offsetExists
     */
    public function offsetExists($value)
    {
        $this->initialize();
        return parent::offsetExists($value);
    }

    /**
     * @param DomainObjectInterface $value The object to look for, or its key in the storage.
     * @return mixed
     *
     * @see \TYPO3\CMS\Extbase\Persistence\ObjectStorage::offsetGet
     */
    public function offsetGet($value)
    {
        $this->initialize();
        return parent::offsetGet($value);
    }

    /**
     * @param DomainObjectInterface $object The object to add.
     * @param mixed $info The data to associate with the object.
     *
     * @see \TYPO3\CMS\Extbase\Persistence\ObjectStorage::offsetSet
     */
    public function offsetSet($object, $info)
    {
        $this->initialize();
        parent::offsetSet($object, $info);
    }

    /**
     * @param DomainObjectInterface $value The object to remove, or its key in the storage.
     *
     * @see \TYPO3\CMS\Extbase\Persistence\ObjectStorage::offsetUnset
     */
    public function offsetUnset($value)
    {
        $this->initialize();
        parent::offsetUnset($value);
    }

    /**
     * @param \TYPO3\CMS\Extbase\Persistence\ObjectStorage $storage The storage containing the elements to remove.
     *
     * @see \TYPO3\CMS\Extbase\Persistence\ObjectStorage::removeAll
     */
    public function removeAll(ObjectStorage $storage)
    {
        $this->initialize();
        parent::removeAll($storage);
    }

    /**
     * @see \TYPO3\CMS\Extbase\Persistence\ObjectStorage::rewind
     */
    public function rewind()
    {
        $this->initialize();
        parent::rewind();
    }

    /**
     * @return bool
     *
     * @see \TYPO3\CMS\Extbase\Persistence\ObjectStorage::valid
     */
    public function valid()
    {
        $this->initialize();
        return parent::valid();
    }

    /**
     * @return array
     *
     * @see \TYPO3\CMS\Extbase\Persistence\ObjectStorage::toArray
     */
    public function toArray()
    {
        $this->initialize();
        return parent::toArray();
    }

    /**
     * @param mixed $object
     * @return int|null
     */
    public function getPosition($object)
    {
        $this->initialize();
        return parent::getPosition($object);
    }
}