typo3/sysext/extbase/Classes/Persistence/Mapper/DataMapper.php

   1 <?php
   2 /***************************************************************
   3  *  Copyright notice
   4  *
   5  *  (c) 2009 Jochen Rau <jochen.rau@typoplanet.de>
   6  *  All rights reserved
   7  *
   8  *  This script is part of the TYPO3 project. The TYPO3 project is
   9  *  free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; either version 2 of the License, or
  12  *  (at your option) any later version.
  13  *
  14  *  The GNU General Public License can be found at
  15  *  http://www.gnu.org/copyleft/gpl.html.
  16  *
  17  *  This script is distributed in the hope that it will be useful,
  18  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  *  GNU General Public License for more details.
  21  *
  22  *  This copyright notice MUST APPEAR in all copies of the script!
  23  ***************************************************************/
  24
  25 /**
  26  * A mapper to map database tables configured in $TCA on domain objects.
  27  *
  28  * @package Extbase
  29  * @subpackage Persistence\Mapper
  30  * @version $ID:$
  31  */
  32 class Tx_Extbase_Persistence_Mapper_DataMapper implements t3lib_Singleton {
  33
  34         /**
  35          * @var Tx_Extbase_Persistence_IdentityMap
  36          */
  37         protected $identityMap;
  38
  39         /**
  40          * @var Tx_Extbase_Reflection_Service
  41          */
  42         protected $reflectionService;
  43
  44         /**
  45          * @var Tx_Extbase_Persistence_QOM_QueryObjectModelFactory
  46          */
  47         protected $QomFactory;
  48
  49         /**
  50          * @var Tx_Extbase_Persistence_Session
  51          */
  52         protected $persistenceSession;
  53
  54         /**
  55          * A reference to the page select object providing methods to perform language and work space overlays
  56          *
  57          * @var t3lib_pageSelect
  58          **/
  59         protected $pageSelectObject;
  60
  61         /**
  62          * Cached data maps
  63          *
  64          * @var array
  65          **/
  66         protected $dataMaps = array();
  67
  68         /**
  69          * @var Tx_Extbase_Persistence_QueryFactoryInterface
  70          */
  71         protected $queryFactory;
  72
  73         /**
  74          * The TYPO3 reference index object
  75          *
  76          * @var t3lib_refindex
  77          **/
  78         protected $referenceIndex;
  79
  80         /**
  81          * Constructs a new mapper
  82          *
  83          */
  84         public function __construct() {
  85                 $this->queryFactory = t3lib_div::makeInstance('Tx_Extbase_Persistence_QueryFactory');
  86         }
  87
  88         /**
  89          * Injects the identity map
  90          *
  91          * @param Tx_Extbase_Persistence_IdentityMap $identityMap
  92          * @return void
  93          */
  94         public function injectIdentityMap(Tx_Extbase_Persistence_IdentityMap $identityMap) {
  95                 $this->identityMap = $identityMap;
  96         }
  97
  98         /**
  99          * Injects the persistence session
 100          *
 101          * @param Tx_Extbase_Persistence_Session $persistenceSession
 102          * @return void
 103          */
 104         public function injectSession(Tx_Extbase_Persistence_Session $persistenceSession) {
 105                 $this->persistenceSession = $persistenceSession;
 106         }
 107
 108         /**
 109          * Injects the Reflection Service
 110          *
 111          * @param Tx_Extbase_Reflection_Service
 112          * @return void
 113          */
 114         public function injectReflectionService(Tx_Extbase_Reflection_Service $reflectionService) {
 115                 $this->reflectionService = $reflectionService;
 116         }
 117
 118         /**
 119          * Sets the query object model factory
 120          *
 121          * @param Tx_Extbase_Persistence_QOM_QueryObjectModelFactory $qomFactory
 122          * @return void
 123          */
 124         public function setQomFactory(Tx_Extbase_Persistence_QOM_QueryObjectModelFactory $qomFactory) {
 125                 $this->qomFactory = $qomFactory;
 126         }
 127
 128         /**
 129          * Maps the (aggregate root) rows and registers them as reconstituted
 130          * with the session.
 131          *
 132          * @param Tx_Extbase_Persistence_RowIteratorInterface $rows
 133          * @return array
 134          */
 135         public function map($className, Tx_Extbase_Persistence_RowIteratorInterface $rows) {
 136                 $objects = array();
 137                 foreach ($rows as $row) {
 138                         $objects[] = $this->mapSingleRow($className, $row);
 139                 }
 140                 return $objects;
 141         }
 142
 143         /**
 144          * Maps a single node into the object it represents
 145          *
 146          * @param Tx_Extbase_Persistence_RowInterface $node
 147          * @return object
 148          */
 149         protected function mapSingleRow($className, Tx_Extbase_Persistence_RowInterface $row) {
 150                 if ($this->identityMap->hasIdentifier($row->getValue('uid'), $className)) {
 151                         $object = $this->identityMap->getObjectByIdentifier($row->getValue('uid'), $className);
 152                 } else {
 153                         $object = $this->createEmptyObject($className);
 154                         $this->thawProperties($object, $row);
 155                         $this->identityMap->registerObject($object, $object->getUid());
 156                         $object->_memorizeCleanState();
 157                         $this->persistenceSession->registerReconstitutedObject($object);
 158                 }
 159                 return $object;
 160         }
 161
 162         /**
 163          * Creates a skeleton of the specified object
 164          *
 165          * @param string $className Name of the class to create a skeleton for
 166          * @return object The object skeleton
 167          */
 168         protected function createEmptyObject($className) {
 169                 // Note: The class_implements() function also invokes autoload to assure that the interfaces
 170                 // and the class are loaded. Would end up with __PHP_Incomplete_Class without it.
 171                 if (!in_array('Tx_Extbase_DomainObject_DomainObjectInterface', class_implements($className))) throw new Tx_Extbase_Object_Exception_CannotReconstituteObject('Cannot create empty instance of the class "' . $className . '" because it does not implement the Tx_Extbase_DomainObject_DomainObjectInterface.', 1234386924);
 172                 $object = unserialize('O:' . strlen($className) . ':"' . $className . '":0:{};');
 173                 return $object;
 174         }
 175
 176         /**
 177          * Sets the given properties on the object.
 178          *
 179          * @param Tx_Extbase_DomainObject_DomainObjectInterface $object The object to set properties on
 180          * @param Tx_Extbase_Persistence_RowInterface $row
 181          * @return void
 182          */
 183         protected function thawProperties(Tx_Extbase_DomainObject_DomainObjectInterface $object, Tx_Extbase_Persistence_RowInterface $row) {
 184                 $className = get_class($object);
 185                 $dataMap = $this->getDataMap($className);
 186                 $properties = $object->_getProperties();
 187                 $object->_setProperty('uid', $row->getValue('uid'));
 188                 foreach ($properties as $propertyName => $propertyValue) {
 189                         if (!$dataMap->isPersistableProperty($propertyName)) continue;
 190                         $columnMap = $dataMap->getColumnMap($propertyName);
 191                         $columnName = $columnMap->getColumnName();
 192                         $propertyValue = NULL;
 193
 194                         $propertyMetaData = $this->reflectionService->getClassSchema($className)->getProperty($propertyName);
 195                         $propertyType = Tx_Extbase_Persistence_PropertyType::valueFromType($propertyMetaData['type']);
 196
 197                         if ($propertyType == Tx_Extbase_Persistence_PropertyType::UNDEFINED) {
 198                                 $propertyType = $columnMap->getPropertyType();
 199                         }
 200
 201                         switch ($propertyType) {
 202                                 case Tx_Extbase_Persistence_PropertyType::STRING;
 203                                 case Tx_Extbase_Persistence_PropertyType::DATE;
 204                                 case Tx_Extbase_Persistence_PropertyType::LONG;
 205                                 case Tx_Extbase_Persistence_PropertyType::DOUBLE;
 206                                 case Tx_Extbase_Persistence_PropertyType::BOOLEAN;
 207                                 if ($row->hasValue($columnName)) {
 208                                         $rawPropertyValue = $row->getValue($columnName);
 209                                         $propertyValue = $dataMap->convertFieldValueToPropertyValue($propertyType, $rawPropertyValue);
 210                                 }
 211                                 break;
 212                                 case (Tx_Extbase_Persistence_PropertyType::REFERENCE):
 213                                         $propertyValue = $row->getValue($columnName);
 214                                         if (!is_null($propertyValue)) {
 215                                                 $fieldValue = $row->getValue($columnName);
 216                                                 $result = $this->fetchRelated($object, $propertyName, $fieldValue);
 217                                                 $propertyValue = $this->mapResultToPropertyValue($object, $propertyName, $result);
 218                                         }
 219                                         break;
 220                                 default:
 221                                         // FIXME throw exception
 222                                         break;
 223                         }
 224                         $object->_setProperty($propertyName, $propertyValue);
 225                 }
 226         }
 227
 228         /**
 229          * Fetches a collection of objects related to a property of a parent object
 230          *
 231          * @param Tx_Extbase_DomainObject_AbstractEntity $parentObject The object instance this proxy is part of
 232          * @param string $propertyName The name of the proxied property in it's parent
 233          * @param mixed $fieldValue The raw field value.
 234          * @param Tx_Extbase_Persistence_Mapper_DataMap $dataMap The corresponding Data Map of the property
 235          * @return mixed The result
 236          */
 237         public function fetchRelated(Tx_Extbase_DomainObject_AbstractEntity $parentObject, $propertyName, $fieldValue = '', $enableLazyLoading = TRUE) {
 238                 $columnMap = $this->getDataMap(get_class($parentObject))->getColumnMap($propertyName);
 239                 $propertyMetaData = $this->reflectionService->getClassSchema(get_class($parentObject))->getProperty($propertyName);
 240                 if ($enableLazyLoading === TRUE && ($propertyMetaData['lazy'] || ($columnMap->getLoadingStrategy() !== Tx_Extbase_Persistence_Mapper_ColumnMap::STRATEGY_EAGER))) {
 241                         if (($propertyMetaData['type'] === 'Tx_Extbase_Persistence_ObjectStorage') || ($columnMap->getLoadingStrategy() === Tx_Extbase_Persistence_Mapper_ColumnMap::STRATEGY_LAZY_STORAGE)) {
 242                                 $result = t3lib_div::makeInstance('Tx_Extbase_Persistence_LazyObjectStorage', $parentObject, $propertyName, $fieldValue);
 243                         } else {
 244                                 $result = t3lib_div::makeInstance('Tx_Extbase_Persistence_LazyLoadingProxy', $parentObject, $propertyName, $fieldValue);
 245                         }
 246                 } else {
 247                         $result = $this->fetchRelatedEager($parentObject, $propertyName, $fieldValue);
 248                 }
 249                 return $result;
 250         }
 251
 252         /**
 253          * Fetches the related objects from the storage backend.
 254          *
 255          * @param Tx_Extbase_DomainObject_AbstractEntity $parentObject The object instance this proxy is part of
 256          * @param string $propertyName The name of the proxied property in it's parent
 257          * @param mixed $fieldValue The raw field value.
 258          * @return void
 259          */
 260         protected function fetchRelatedEager(Tx_Extbase_DomainObject_AbstractEntity $parentObject, $propertyName, $fieldValue = '') {
 261                 if ($fieldValue === '') return array();
 262                 $query = $this->getPreparedQuery($parentObject, $propertyName, $fieldValue);
 263                 return $query->execute();
 264         }
 265
 266         /**
 267          * Builds and returns the prepared query, ready to be executed.
 268          *
 269          * @param Tx_Extbase_DomainObject_AbstractEntity $parentObject
 270          * @param string $propertyName
 271          * @param string $fieldValue
 272          * @return void
 273          */
 274         protected function getPreparedQuery(Tx_Extbase_DomainObject_AbstractEntity $parentObject, $propertyName, $fieldValue = '') {
 275                 $columnMap = $this->getDataMap(get_class($parentObject))->getColumnMap($propertyName);
 276                 $queryFactory = t3lib_div::makeInstance('Tx_Extbase_Persistence_QueryFactory');
 277                 $parentKeyFieldName = $columnMap->getParentKeyFieldName();
 278                 $childSortByFieldName = $columnMap->getChildSortByFieldName();
 279                 if ($columnMap->getTypeOfRelation() === Tx_Extbase_Persistence_Mapper_ColumnMap::RELATION_HAS_ONE) {
 280                         $query = $queryFactory->create($this->getType($parentObject, $propertyName));
 281                         if (isset($parentKeyFieldName)) {
 282                                 $query->matching($query->equals($parentKeyFieldName, $parentObject->getUid()));
 283                         } else {
 284                                 $query->matching($query->withUid(intval($fieldValue)));
 285                         }
 286                 } elseif ($columnMap->getTypeOfRelation() === Tx_Extbase_Persistence_Mapper_ColumnMap::RELATION_HAS_MANY) {
 287                         $query = $queryFactory->create($this->getElementType($parentObject, $propertyName));
 288                         // TODO: This is an ugly hack, just ignoring the storage page state from here. Actually, the query settings would have to be passed into the DataMapper, so we can respect
 289                         // enableFields and storage page settings.
 290                         $query->getQuerySettings()->setRespectStoragePage(FALSE);
 291                         if (!empty($childSortByFieldName)) {
 292                                 $query->setOrderings(array($childSortByFieldName => Tx_Extbase_Persistence_QueryInterface::ORDER_ASCENDING));
 293                         }
 294                         if (isset($parentKeyFieldName)) {
 295                                 $query->matching($query->equals($parentKeyFieldName, $parentObject->getUid()));
 296                         } else {
 297                                 $query->matching($query->equals('uid', t3lib_div::intExplode(',', $fieldValue)));
 298                         }
 299                 } elseif ($columnMap->getTypeOfRelation() === Tx_Extbase_Persistence_Mapper_ColumnMap::RELATION_HAS_AND_BELONGS_TO_MANY) {
 300                         $query = $queryFactory->create($this->getElementType($parentObject, $propertyName));
 301                         // TODO: This is an ugly hack, just ignoring the storage page state from here. Actually, the query settings would have to be passed into the DataMapper, so we can respect
 302                         // enableFields and storage page settings.
 303                         $query->getQuerySettings()->setRespectStoragePage(FALSE);
 304                         $relationTableName = $columnMap->getRelationTableName();
 305                         $left = $this->qomFactory->selector(NULL, $relationTableName);
 306                         $childClassName = $this->getElementType($parentObject, $propertyName);
 307                         $childTableName = $columnMap->getChildTableName();
 308                         $right = $this->qomFactory->selector($childClassName, $childTableName);
 309                         $joinCondition = $this->qomFactory->equiJoinCondition($relationTableName, $columnMap->getChildKeyFieldName(), $childTableName, 'uid');
 310                         $source = $this->qomFactory->join(
 311                                 $left,
 312                                 $right,
 313                                 Tx_Extbase_Persistence_QOM_QueryObjectModelConstantsInterface::JCR_JOIN_TYPE_INNER,
 314                                 $joinCondition
 315                                 );
 316
 317                         $query->setSource($source);
 318                         if (!empty($childSortByFieldName)) {
 319                                 $query->setOrderings(array($relationTableName . '.' . $childSortByFieldName => Tx_Extbase_Persistence_QueryInterface::ORDER_ASCENDING));
 320                         }
 321
 322                         // attempt to support MM_match_fields
 323                         $conditions = $query->equals($parentKeyFieldName, $parentObject->getUid());
 324
 325                         $relationTableMatchFields = $columnMap->getRelationTableMatchFields();
 326                         if (count($relationTableMatchFields)) {
 327                                 foreach($relationTableMatchFields as $relationTableMatchFieldName => $relationTableMatchFieldValue) {
 328                                         $relationMatchCondition = $query->equals($relationTableName . '.' . $relationTableMatchFieldName, $relationTableMatchFieldValue);
 329                                         $conditions = $query->logicalAnd($conditions, $relationMatchCondition);
 330                                 }
 331                         }
 332                         $query->matching($conditions);
 333
 334                 } else {
 335                         throw new Tx_Extbase_Persistence_Exception('Could not determine type of relation.', 1252502725);
 336                 }
 337                 return $query;
 338         }
 339
 340         /**
 341          * Returns the given result as property value of the specified property type.
 342          *
 343          * @param mixed $result The result could be an object or an ObjectStorage
 344          * @param array $propertyMetaData The property meta data
 345          * @return void
 346          */
 347         public function mapResultToPropertyValue(Tx_Extbase_DomainObject_AbstractEntity $parentObject, $propertyName, $result) {
 348                 if ($result instanceof Tx_Extbase_Persistence_LoadingStrategyInterface) {
 349                         $propertyValue = $result;
 350                 } else {
 351                         $propertyMetaData = $this->reflectionService->getClassSchema(get_class($parentObject))->getProperty($propertyName);
 352                         $columnMap = $this->getDataMap(get_class($parentObject))->getColumnMap($propertyName);
 353                         if (in_array($propertyMetaData['type'], array('array', 'ArrayObject', 'Tx_Extbase_Persistence_ObjectStorage'))) {
 354                                 $elementType = $this->getElementType($parentObject, $propertyName);
 355                                 $objects = array();
 356                                 foreach ($result as $value) {
 357                                         $objects[] = $value;
 358                                 }
 359
 360                                 if ($propertyMetaData['type'] === 'ArrayObject') {
 361                                         $propertyValue = new ArrayObject($objects);
 362                                 } elseif ($propertyMetaData['type'] === 'Tx_Extbase_Persistence_ObjectStorage') {
 363                                         $propertyValue = new Tx_Extbase_Persistence_ObjectStorage();
 364                                         foreach ($objects as $object) {
 365                                                 $propertyValue->attach($object);
 366                                         }
 367                                 } else {
 368                                         $propertyValue = $objects;
 369                                 }
 370                         } elseif (strpos($propertyMetaData['type'], '_') !== FALSE) {
 371                                 $propertyValue = current($result);
 372                         }
 373                 }
 374                 return $propertyValue;
 375         }
 376
 377         /**
 378          * Counts the number of related objects assigned to a property of a parent object
 379          *
 380          * @param Tx_Extbase_DomainObject_AbstractEntity $parentObject The object instance this proxy is part of
 381          * @param string $propertyName The name of the proxied property in it's parent
 382          * @param mixed $fieldValue The raw field value.
 383          */
 384         public function countRelated(Tx_Extbase_DomainObject_AbstractEntity $parentObject, $propertyName, $fieldValue = '') {
 385                 $query = $this->getPreparedQuery($parentObject, $propertyName, $fieldValue);
 386                 return $query->count();
 387         }
 388
 389         /**
 390          * Delegates the call to the Data Map.
 391          * Returns TRUE if the property is persistable (configured in $TCA)
 392          *
 393          * @param string $className The property name
 394          * @param string $propertyName The property name
 395          * @return boolean TRUE if the property is persistable (configured in $TCA)
 396          */
 397         public function isPersistableProperty($className, $propertyName) {
 398                 $dataMap = $this->getDataMap($className);
 399                 return $dataMap->isPersistableProperty($propertyName);
 400         }
 401
 402         /**
 403          * Returns a data map for a given class name
 404          *
 405          * @param string $className The class name you want to fetch the Data Map for
 406          * @return Tx_Extbase_Persistence_Mapper_DataMap The data map
 407          */
 408         public function getDataMap($className) {
 409                 if (!is_string($className) || strlen($className) === 0) throw new Tx_Extbase_Persistence_Exception('No class name was given to retrieve the Data Map for.', 1251315965);
 410                 if (!isset($this->dataMaps[$className])) {
 411                         // FIXME This is too expensive for table name aliases -> implement a DataMapBuilder (knowing the aliases defined in $TCA)
 412                         $columnMapping = array();
 413                         $tableName = '';
 414                         $extbaseSettings = Tx_Extbase_Dispatcher::getExtbaseFrameworkConfiguration();
 415                         if (is_array($extbaseSettings['persistence']['classes'][$className])) {
 416                                 $persistenceSettings = $extbaseSettings['persistence']['classes'][$className];
 417                                 if (is_string($persistenceSettings['mapping']['tableName']) && strlen($persistenceSettings['mapping']['tableName']) > 0) {
 418                                         $tableName = $persistenceSettings['mapping']['tableName'];
 419                                 }
 420                                 if (is_array($persistenceSettings['mapping']['columns'])) {
 421                                         $columnMapping = $persistenceSettings['mapping']['columns'];
 422                                 }
 423                         } elseif (class_exists($className)) {
 424                                 foreach (class_parents($className) as $parentClassName) {
 425                                         $persistenceSettings = $extbaseSettings['persistence']['classes'][$parentClassName];
 426                                         if (is_array($persistenceSettings)) {
 427                                                 if (is_string($persistenceSettings['mapping']['tableName']) && strlen($persistenceSettings['mapping']['tableName']) > 0) {
 428                                                         $tableName = $persistenceSettings['mapping']['tableName'];
 429                                                 }
 430                                                 if (is_array($persistenceSettings['mapping']['columns'])) {
 431                                                         $columnMapping = $persistenceSettings['mapping']['columns'];
 432                                                 }
 433                                         }
 434                                         break;
 435                                 }
 436                         } else {
 437                                 throw new Tx_Extbase_Persistence_Exception('Could not determine a Data Map for given class name.', 1256067130);
 438                         }
 439
 440                         $dataMap = new Tx_Extbase_Persistence_Mapper_DataMap($className, $tableName, $columnMapping);
 441                         $this->dataMaps[$className] = $dataMap;
 442                 }
 443                 return $this->dataMaps[$className];
 444         }
 445
 446         /**
 447          * Returns the selector (table) name for a given class name.
 448          *
 449          * @param string $className
 450          * @return string The selector name
 451          */
 452         public function convertClassNameToTableName($className) {
 453                 return $this->getDataMap($className)->getTableName();
 454         }
 455
 456         /**
 457          * Returns the column name for a given property name of the specified class.
 458          *
 459          * @param string $className
 460          * @param string $propertyName
 461          * @return string The column name
 462          */
 463         public function convertPropertyNameToColumnName($propertyName, $className = '') {
 464                 if (!empty($className)) {
 465                         $dataMap = $this->getDataMap($className);
 466                         if ($dataMap !== NULL) {
 467                                 $columnMap = $dataMap->getColumnMap($propertyName);
 468                                 if ($columnMap !== NULL) {
 469                                         return $columnMap->getColumnName();
 470                                 }
 471                         }
 472                 }
 473                 return Tx_Extbase_Utility_Extension::convertCamelCaseToLowerCaseUnderscored($propertyName);
 474         }
 475
 476         /**
 477          * Returns the type of a child object.
 478          *
 479          * @param Tx_Extbase_DomainObject_AbstractEntity $parentObject The object instance this proxy is part of
 480          * @param string $propertyName The name of the proxied property in it's parent
 481          * @return string The class name of the child object
 482          */
 483         protected function getType(Tx_Extbase_DomainObject_AbstractEntity $parentObject, $propertyName) {
 484                 $propertyMetaData = $this->reflectionService->getClassSchema(get_class($parentObject))->getProperty($propertyName);
 485                 $columnMap = $this->getDataMap(get_class($parentObject))->getColumnMap($propertyName);
 486                 $childClassName = $columnMap->getChildClassName();
 487                 if (!empty($childClassName)) {
 488                         $elementType = $childClassName;
 489                 } elseif (!empty($propertyMetaData['type'])) {
 490                         $elementType = $propertyMetaData['type'];
 491                 } else {
 492                         throw new Tx_Extbase_Persistence_Exception_UnexpectedTypeException('Could not determine the child object object type.', 1251315967);
 493                 }
 494                 return $elementType;
 495         }
 496
 497         /**
 498          * Returns the type of the elements inside an ObjectStorage or array.
 499          *
 500          * @param Tx_Extbase_DomainObject_AbstractEntity $parentObject The object instance this proxy is part of
 501          * @param string $propertyName The name of the proxied property in it's parent
 502          * @return string The class name of the elements inside an ObjectStorage
 503          */
 504         protected function getElementType(Tx_Extbase_DomainObject_AbstractEntity $parentObject, $propertyName) {
 505                 $propertyMetaData = $this->reflectionService->getClassSchema(get_class($parentObject))->getProperty($propertyName);
 506                 $columnMap = $this->getDataMap(get_class($parentObject))->getColumnMap($propertyName);
 507                 $childClassName = $columnMap->getChildClassName();
 508                 if (!empty($childClassName)) {
 509                         $elementType = $childClassName;
 510                 } elseif (!empty($propertyMetaData['elementType'])) {
 511                         $elementType = $propertyMetaData['elementType'];
 512                 } else {
 513                         throw new Tx_Extbase_Persistence_Exception_UnexpectedTypeException('Could not determine the type of the contained objects.', 1251315966);
 514                 }
 515                 return $elementType;
 516         }
 517
 518 }
 519 ?>