Source for file HarmoniAsset.class.php

<?php
/**
 * @package harmoni.osid_v2.repository
 * 
 * @copyright Copyright &copy; 2005, Middlebury College
 * @license http://www.gnu.org/copyleft/gpl.html GNU General Public License (GPL)
 *
 * @version $Id: HarmoniAsset.class.php,v 1.49 2007/09/17 16:44:36 adamfranco Exp $
 */
 
require_once(HARMONI."oki2/repository/HarmoniAsset.interface.php");
require_once(HARMONI."oki2/repository/HarmoniRecord.class.php");
require_once(HARMONI."oki2/repository/HarmoniRecordIterator.class.php");
require_once(HARMONI."oki2/shared/HarmoniIterator.class.php");
 
require_once(dirname(__FILE__)."/FromNodesAssetIterator.class.php");
 
/**
 * Asset manages the Asset itself.  Assets have content as well as Records
 * appropriate to the AssetType and RecordStructures for the Asset.  Assets
 * may also contain other Assets.
 * 
 * 
 * @package harmoni.osid_v2.repository
 * 
 * @copyright Copyright &copy;2005, Middlebury College
 * @license http://www.gnu.org/copyleft/gpl.html GNU General Public License
 *
 * @version $Id: HarmoniAsset.class.php,v 1.49 2007/09/17 16:44:36 adamfranco Exp $
 */
 
class HarmoniAsset
    extends HarmoniAssetInterface
{ // begin Asset
    
    
    
    var $_configuration;
    var $_versionControlAll = FALSE;
    var $_versionControlTypes;
    var $_hierarchy;
    var $_node;
    var $_repository;
    
    var $_recordIDs;
    var $_createdRecords;
    var $_createdRecordStructures;
    
    var $_effectiveDate;
    var $_expirationDate;
    var $_datesInDB = FALSE;
    
    /**
     * Constructor
     */
    function HarmoniAsset ($hierarchy, $repository, $id, $configuration) {
         // Get the node coresponding to our id
        $this->_hierarchy =$hierarchy;
        $this->_node =$this->_hierarchy->getNode($id);
        $this->_repository =$repository;
        
        $this->_recordIDs = array();
        $this->_createdRecords = array();
        $this->_createdRecordStructures = array();
        
        // Store our configuration
        $this->_configuration =$configuration;
        $this->_versionControlAll = ($configuration->getProperty('version_control_all'))?TRUE:FALSE;
        if (is_array($configuration->getProperty('version_control_types'))) {
            ArgumentValidator::validate($configuration->getProperty('version_control_types'), ArrayValidatorRuleWithRule::getRule( ExtendsValidatorRule::getRule("Type")));
            $this->_versionControlTypes =$configuration->getProperty('version_control_types');
        } else {
            $this->_versionControlTypes = array();
        }
        
        $this->_dbIndex = $configuration->getProperty('database_index');
     }
 
    /**
     * Get the display name for this Asset.
     *  
     * @return string 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}
     * 
     * @access public
     */
    function getDisplayName () { 
        return $this->_node->getDisplayName();
    }
 
     /**
     * Update the display name for this Asset.
     * 
     * @param string $displayName 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}, {@link }
     *          org.osid.repository.RepositoryException#NULL_ARGUMENT
     *          NULL_ARGUMENT}
     * 
     * @access public
     */
    function updateDisplayName ( $displayName ) { 
        $this->_node->updateDisplayName($displayName);
        $this->updateModificationDate();
    }
 
     /**
     * Get the description for this Asset.
     *  
     * @return string 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}
     * 
     * @access public
     */
    function getDescription () { 
        return $this->_node->getDescription();
    }
 
    /**
     * Update the description for this Asset.
     * 
     * @param string $description 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}, {@link }
     *          org.osid.repository.RepositoryException#NULL_ARGUMENT
     *          NULL_ARGUMENT}
     * 
     * @access public
     */
    function updateDescription ( $description ) { 
        $this->_node->updateDescription($description);
        $this->updateModificationDate();
    }
 
     /**
     * Get the unique Id for this Asset.
     *  
     * @return object Id 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}
     * 
     * @access public
     */
    function getId () { 
        return $this->_node->getId();
    }
    
    /**
     * Get the Id of the Repository in which this Asset resides.  This is set
     * by the Repository's createAsset method.
     *  
     * WARNING::IMPLEMENTATION AND DOCUMENTATION DIFFER
     *
     * @return object Id 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}
     * 
     * @access public
     */
    function getRepository () { 
 
        return $this->_repository;
    }
 
    /**
     * Get an Asset's content.  This method can be a convenience if one is not
     * interested in all the structure of the Records.
     *  
     * @return object mixed (original type: java.io.Serializable)
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}
     * 
     * @access public
     */
    function getContent () { 
    
         $idManager = Services::getService("Id");
         $recordMgr = Services::getService("RecordManager");
         
         // Ready our type for comparisson
         $contentType = "edu.middlebury.harmoni.repository.asset_content";
         $myId =$this->_node->getId();
         
         // Get the content DataSet.
         $myRecordSet =$recordMgr->fetchRecordSet($myId->getIdString());
         $myRecordSet->loadRecords();
        $contentRecords =$myRecordSet->getRecordsByType($contentType);
        
        if (isset($contentRecords[0]) && $contentRecords[0])
            return $contentRecords[0]->getValue("Content");
        else
            return new Blob();
    }
 
    /**
     * Update an Asset's content.
     * 
     * @param object mixed $content (original type: java.io.Serializable)
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}, {@link }
     *          org.osid.repository.RepositoryException#NULL_ARGUMENT
     *          NULL_ARGUMENT}
     * 
     * @access public
     */
    function updateContent ( $content ) { 
         ArgumentValidator::validate($content, ExtendsValidatorRule::getRule("Blob"));
         $idManager = Services::getService("Id");
         $recordMgr = Services::getService("RecordManager");
         
         // Ready our type for comparisson
         $contentType = "edu.middlebury.harmoni.repository.asset_content";
         $myId =$this->_node->getId();
         
         // Get the content DataSet.
         $myRecordSet =$recordMgr->fetchRecordSet($myId->getIdString());
         $myRecordSet->loadRecords();
        $contentRecords =$myRecordSet->getRecordsByType($contentType);
 
         if (count($contentRecords)) {
             $contentRecord =$contentRecords[0];
             
             $contentRecord->setValue("Content", $content);
         
            $contentRecord->commit(TRUE);
         } else {
            // Set up and create our new record
            $schemaMgr = Services::getService("SchemaManager");
            $contentSchema =$schemaMgr->getSchemaByID($contentType);
            $contentSchema->load();
//            printpre($contentSchema->getAllLabels());
            
            // Decide if we want to version-control this field.
            $versionControl = $this->_versionControlAll;
            if (!$versionControl) {
                foreach ($this->_versionControlTypes as $key => $val) {
                    if ($contentType == $this->_versionControlTypes[$key]) {
                        $versionControl = TRUE;
                        break;
                    }
                }
            }
            
            $contentRecord =$recordMgr->createRecord($contentType, $versionControl);
            
            $contentRecord->setValue("Content", $content);
         
            $contentRecord->commit(TRUE);
    
            // Add the record to our group
            $myRecordSet->add($contentRecord);
            $myRecordSet->commit(TRUE);
        }
        $this->updateModificationDate();
    }
 
    /**
     * Get the date at which this Asset is effective.
     *  
     * @return object DateAndTime 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}
     * 
     * @access public
     */
    function getEffectiveDate () { 
    
        if (!isset($this->_effectiveDate)) {
            $this->_loadDates();
        }
        
        return $this->_effectiveDate;
    }
 
    /**
     * Update the date at which this Asset is effective.
     * 
     * @param object DateAndTime $effectiveDate OR NULL
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}, {@link }
     *          org.osid.repository.RepositoryException#NULL_ARGUMENT
     *          NULL_ARGUMENT}, {@link }
     *          org.osid.repository.RepositoryException#EFFECTIVE_PRECEDE_EXPIRATION}
     * 
     * @access public
     */
    function updateEffectiveDate ( $effectiveDate ) { 
        ArgumentValidator::validate($effectiveDate,
            OptionalRule::getRule(
                HasMethodsValidatorRule::getRule("asDateAndTime")));
        
        // Make sure that we have dates from the DB if they exist.
        $this->_loadDates();
        // Update our date in preparation for DB updating
        $this->_effectiveDate =$effectiveDate;
        // Store the dates
        $this->_storeDates();
    }
 
    /**
     * Get the date at which this Asset expires.
     *  
     * @return object DateAndTime 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}
     * 
     * @access public
     */
    function getExpirationDate () { 
        if (!$this->_expirationDate) {
            $this->_loadDates();
        }
        
        return $this->_expirationDate;
    }
 
    
    /**
     * Update the date at which this Asset expires.
     * 
     * @param object DateAndTime $expirationDate 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}, {@link }
     *          org.osid.repository.RepositoryException#NULL_ARGUMENT
     *          NULL_ARGUMENT}, {@link }
     *          org.osid.repository.RepositoryException#EFFECTIVE_PRECEDE_EXPIRATION}
     * 
     * @access public
     */
    function updateExpirationDate ( $expirationDate ) { 
        ArgumentValidator::validate($expirationDate,
            OptionalRule::getRule(
                HasMethodsValidatorRule::getRule("asDateAndTime")));
            
        // Make sure that we have dates from the DB if they exist.
        $this->_loadDates();
        // Update our date in preparation for DB updating
        $this->_expirationDate =$expirationDate;
        // Store the dates
        $this->_storeDates();
    }
 
    /**
     * Add an Asset to this Asset.
     * 
     * @param object Id $assetId 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}, {@link }
     *          org.osid.repository.RepositoryException#NULL_ARGUMENT
     *          NULL_ARGUMENT}, {@link }
     *          org.osid.repository.RepositoryException#UNKNOWN_ID UNKNOWN_ID},
     *          {@link org.osid.repository.RepositoryException#ALREADY_ADDED}
     *          ALREADY_ADDED}
     * 
     * @access public
     */
    function addAsset ( $assetId ) { 
        $node =$this->_hierarchy->getNode($assetId);
        $oldParents =$node->getParents();
        // We are assuming a single-parent hierarchy
        $oldParent =$oldParents->next();
        $node->changeParent($oldParent->getId(), $this->_node->getId());
        
        $this->save();
        $this->updateModificationDate();
    }
 
    /**
     * Remove an Asset from this Asset.  This method does not delete the Asset
     * from the Repository.
     * 
     * @param object Id $assetId 
     * @param boolean $includeChildren 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}, {@link }
     *          org.osid.repository.RepositoryException#NULL_ARGUMENT
     *          NULL_ARGUMENT}, {@link }
     *          org.osid.repository.RepositoryException#UNKNOWN_ID UNKNOWN_ID}
     * 
     * @access public
     */
    function removeAsset ( $assetId, $includeChildren = FALSE ) { 
        $node =$this->_hierarchy->getNode($assetId);
    
        if (!$includeChildren) {
            // Move the children to the current asset before moving
            // the asset to the repository root
            $children =$node->getChildren();
            while ($children->hasNext()) {
                $child =$children->next();
                $child->changeParent($node->getId(), $this->_node->getId());
            }
        }
        
        // Move the asset to the repository root.
        $node->changeParent($this->_node->getId(), $this->_repository->getId());
        
        $this->save();
        $this->updateModificationDate();
    }
 
     /**
     * Get all the Assets in this Asset. Iterators return a set, one at a
     * time.
     *  
     * @return object AssetIterator 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}
     * 
     * @access public
     */
    function getAssets () {         
        // create an AssetIterator and return it
        $assetIterator = new FromNodesAssetIterator(
                                    $this->_node->getChildren(),
                                    $this->_repository);
        
        return $assetIterator;
    
    }
    
    /**
     * Get the parents of this asset, Iterators return a set one at a time.
     *
     * WARNING: NOT IN OSID
     *
     * @return object AssetIterator 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}
     * 
     * @access public
     */
    function getParents () { 
        $assets = array();
        $parents =$this->_node->getParents();
        
        $manager = Services::getService("Repository");
        $repositoryKeyType =$manager->repositoryKeyType;
        
        while ($parents->hasNext()) {
            $parent =$parents->next();
            if (!$repositoryKeyType->isEqual($parent->getType()))
                $assets[] =$this->_repository->getAsset($parent->getId());
        }
        
        // create an AssetIterator and return it
        $assetIterator = new HarmoniAssetIterator($assets);
        
        return $assetIterator;
    }
    
    /**
     * Answer an iterator of the TraversalInfo of the decendent Assets
     * (children, grandchildren, etc).
     * WARNING: NOT IN OSID
     * 
     * @return object TraversalInfoIterator 
     * @access public
     * @since 12/15/05
     */
    function getDescendentInfo () {
        $traversalInfo =$this->_hierarchy->traverse(
            $this->getId(),
            Hierarchy::TRAVERSE_MODE_DEPTH_FIRST(),
            Hierarchy::TRAVERSE_DIRECTION_DOWN(),
            Hierarchy::TRAVERSE_LEVELS_ALL());
            
        return $traversalInfo;
    }
    
    /**
     * Get the parents of this asset, Iterators return a set one at a time.
     *
     * WARNING: NOT IN OSID
     *
     * @param object Type $assetType 
     *  
     * @return object AssetIterator 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}, {@link }
     *          org.osid.repository.RepositoryException#NULL_ARGUMENT
     *          NULL_ARGUMENT}, {@link }
     *          org.osid.repository.RepositoryException#UNKNOWN_TYPE
     *          UNKNOWN_TYPE}
     * 
     * @access public
     */
    function getParentsByType ( $assetType ) {
        $assets = array();
        $parents =$this->_node->getParents();
        while ($parents->hasNext()) {
            $parent =$parents->next();
            if ($assetType->isEqual($parent->getType()))
                $assets[] =$this->_repository->getAsset($parent->getId());
        }
        
        // create an AssetIterator and return it
        $assetIterator = new HarmoniAssetIterator($assets);
        
        return $assetIterator;
    }
    
     /**
     * Get all the Assets of the specified AssetType in this Repository.
     * Iterators return a set, one at a time.
     * 
     * @param object Type $assetType 
     *  
     * @return object AssetIterator 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}, {@link }
     *          org.osid.repository.RepositoryException#NULL_ARGUMENT
     *          NULL_ARGUMENT}, {@link }
     *          org.osid.repository.RepositoryException#UNKNOWN_TYPE
     *          UNKNOWN_TYPE}
     * 
     * @access public
     */
    
    function getAssetsByType ( $assetType ) { 
        $assets = array();
        $children =$this->_node->getChildren();
        while ($children->hasNext()) {
            $child =$children->next();
            if ($assetType->isEqual($child->getType()))
                $assets[] =$this->_repository->getAsset($child->getId());
        }
        
        $obj = new HarmoniAssetIterator($assets);
        
        return $obj;
    }
 
     /**
     * Create a new Asset Record of the specified RecordStructure.   The
     * implementation of this method sets the Id for the new object.
     * 
     * @param object Id $recordStructureId 
     *  
     * @return object Record 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}, {@link }
     *          org.osid.repository.RepositoryException#NULL_ARGUMENT
     *          NULL_ARGUMENT}, {@link }
     *          org.osid.repository.RepositoryException#UNKNOWN_ID UNKNOWN_ID}
     * 
     * @access public
     */
    function createRecord ( $recordStructureId ) { 
        ArgumentValidator::validate($recordStructureId, ExtendsValidatorRule::getRule("Id"));
        
        // If this is a schema that is hard coded into our implementation, create
        // a record for that schema.
        if (in_array($recordStructureId->getIdString(), array_keys($this->_repository->_builtInTypes))) 
        {
            // Create an Id for the record;
            $idManager = Services::getService("Id");
            $newId =$idManager->createId();
    
            // instantiate the new record.
            $recordClass = $this->_repository->_builtInTypes[$recordStructureId->getIdString()];
            $recordStructure =$this->_repository->getRecordStructure($recordStructureId);
            $record = new $recordClass($recordStructure, $newId, $this->_configuration, $this);
            
            // store a relation to the record
            $dbHandler = Services::getService("DatabaseManager");
            $query = new InsertQuery;
            $query->setTable("dr_asset_record");
            $query->setColumns(array("fk_asset", "fk_record", "structure_id"));
            $myId =$this->getId();
            $query->addRowOfValues(array(
                                "'".$myId->getIdString()."'",
                                "'".$newId->getIdString()."'",
                                "'".$recordStructureId->getIdString()."'"));
            $result =$dbHandler->query($query, $this->_dbIndex);
        } 
        
        // Otherwise use the data manager
        else {
            // Get the DataSetGroup for this Asset
            $recordMgr = Services::getService("RecordManager");
            $myId =$this->_node->getId();
            $myGroup =$recordMgr->fetchRecordSet($myId->getIdString());
            
            // Get the recordStructure needed.
            $recordStructures =$this->_repository->getRecordStructures();
            while ($recordStructures->hasNext()) {
                $structure =$recordStructures->next();
                if ($recordStructureId->isEqual($structure->getId()))
                    break;
            }
            
            //     get the type for the new data set.
            $schemaMgr = Services::getService("SchemaManager");
            $schemaID = $recordStructureId->getIdString();
//            $type =$schemaMgr->getSchemaByID($recordStructureId->getIdString());
            
            // Set up and create our new dataset
            // Decide if we want to version-control this field.
                $versionControl = $this->_versionControlAll;
                if (!$versionControl) {
                    foreach ($this->_versionControlTypes as $key => $val) {
                        if ($schemaID == $this->_versionControlTypes[$key]) {
                            $versionControl = TRUE;
                            break;
                        }
                    }
                }
                
                $newRecord =$recordMgr->createRecord($schemaID, $versionControl);
            
            // The ignoreMandatory Allows this record to be created without checking for
            // values on mandatory fields. These constraints should be checked when
            // validateAsset() is called.
            $newRecord->commit(TRUE);
            
            // Add the DataSet to our group
            $myGroup->add($newRecord);
            
            // us the RecordStructure and the dataSet to create a new Record
            $record = new HarmoniRecord($structure, $newRecord, $this);
        }
        
        // Add the record to our createdRecords array, so we can pass out references to it.
        $recordId =$record->getId();
        $this->_createdRecords[$recordId->getIdString()] =$record;
        
        $this->save();
        $this->updateModificationDate();
        
        return $record;
    }
 
     /**
     * Add the specified RecordStructure and all the related Records from the
     * specified asset.  The current and future content of the specified
     * Record is synchronized automatically.
     * 
     * @param object Id $assetId 
     * @param object Id $recordStructureId 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}, {@link }
     *          org.osid.repository.RepositoryException#NULL_ARGUMENT
     *          NULL_ARGUMENT}, {@link }
     *          org.osid.repository.RepositoryException#UNKNOWN_ID UNKNOWN_ID},
     *          {@link }
     *          org.osid.repository.RepositoryException#ALREADY_INHERITING_STRUCTURE
     *          ALREADY_INHERITING_STRUCTURE}
     * 
     * @access public
     */
    function inheritRecordStructure ( $assetId, $recordStructureId ) { 
    
        // Check the arguments
        ArgumentValidator::validate($recordStructureId, ExtendsValidatorRule::getRule("Id"));
        ArgumentValidator::validate($assetId, ExtendsValidatorRule::getRule("Id"));
        
        // If this is a schema that is hard coded into our implementation, create
        // a record for that schema.
        if (in_array($recordStructureId->getIdString(), array_keys($this->_repository->_builtInTypes))) 
        {
            // Create an Id for the record;
            $idManager = Services::getService("Id");
            $dbHandler = Services::getService("DatabaseManager");
    
            // get the record ids that we want to inherit
            $query = new SelectQuery();
            $query->addTable("dr_asset_record");
            $query->addColumn("fk_record");
            $query->addWhere("fk_asset = '".$assetId->getIdString()."'");
            $query->addWhere("structure_id = '".$recordStructureId->getIdString()."'", _AND);
            
            $result =$dbHandler->query($query, $this->_dbIndex);
            
            // store a relation to the record
            $dbHandler = Services::getService("DatabaseManager");
            $query = new InsertQuery;
            $query->setTable("dr_asset_record");
            $query->setColumns(array("fk_asset", "fk_record", "structure_id"));
            
            $myId =$this->getId();
            
            while ($result->hasMoreRows()) {
                $query->addRowOfValues(array(
                                    "'".$myId->getIdString()."'",
                                    "'".$result->field("fk_record")."'",
                                    "'".$recordStructureId->getIdString()."'"));
                $dbHandler->query($query, $this->_dbIndex);
                $result->advanceRow();
            }
            
            $result->free();
        } 
        
        // Otherwise use the data manager
        else {
            // Get our managers:
            $recordMgr = Services::getService("RecordManager");
            $idMgr = Services::getService("Id");
        
            // Get the DataSetGroup for this Asset
            $myId =$this->_node->getId();
            $mySet =$recordMgr->fetchRecordSet($myId->getIdString());
            
            // Get the DataSetGroup for the source Asset
            $otherSet =$recordMgr->fetchRecordSet($assetId->getIdString());
            $otherSet->loadRecords(RECORD_FULL);
            $records =$otherSet->getRecords();
            
            // Add all of DataSets (Records) of the specified RecordStructure and Asset
            // to our RecordSet.
            foreach (array_keys($records) as $key) {
                // Get the ID of the current DataSet's TypeDefinition
                $schema =$records[$key]->getSchema();
                $schemaId =$idMgr->getId($schema->getID());
                
                // If the current DataSet's DataSetTypeDefinition's ID is the same as
                // the RecordStructure ID that we are looking for, add that dataSet to our
                // DataSetGroup.
                if ($recordStructureId->isEqual($schemaId)) {
                    $mySet->add($records[$key]);
                }
            }
            
            // Save our DataSetGroup
            $mySet->commit(TRUE);
        }
        
        $this->updateModificationDate();
    }
 
    /**
     * Add the specified RecordStructure and all the related Records from the
     * specified asset.
     * 
     * @param object Id $assetId 
     * @param object Id $recordStructureId 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}, {@link }
     *          org.osid.repository.RepositoryException#NULL_ARGUMENT
     *          NULL_ARGUMENT}, {@link }
     *          org.osid.repository.RepositoryException#UNKNOWN_ID UNKNOWN_ID},
     *          {@link }
     *          org.osid.repository.RepositoryException#CANNOT_COPY_OR_INHERIT_SELF
     *          CANNOT_COPY_OR_INHERIT_SELF}
     * 
     * @access public
     */
    function copyRecordStructure ( $assetId, $recordStructureId ) { 
    
        // Check the arguments    
        ArgumentValidator::validate($recordStructureId, ExtendsValidatorRule::getRule("Id"));
        ArgumentValidator::validate($assetId, ExtendsValidatorRule::getRule("Id"));
        
        // Get our managers:
        $recordMgr = Services::getService("RecordManager");
        $idMgr = Services::getService("Id");
        
        // Get the RecordSet for this Asset
        $myId =$this->_node->getId();
        $set =$recordMgr->fetchRecordSet($myId->getIdString());
        
        // Get the DataSetGroup for the source Asset
        $otherSet =$recordMgr->fetchRecordSet($assetId->getIdString());
        $otherSet->loadRecords(RECORD_FULL);
        $records =$otherSet->getRecords();
        
        // Add all of Records (Records) of the specified RecordStructure and Asset
        // to our RecordSet.
        foreach (array_keys($records) as $key) {
            // Get the ID of the current DataSet's TypeDefinition
            $schema =$records[$key]->getSchema();
            $schemaId =$idMgr->getId($schema->getID());
            
            // If the current Record's Schema ID is the same as
            // the RecordStructure ID that we are looking for, add replicates of that Record
            // to our RecordSet.
            if ($recordStructureId->isEqual($schemaId)) {
                $newRecord =$records[$key]->replicate();
                $set->add($newRecord);
            }
        }
        
        // Save our RecordSet
        $set->commit(TRUE);
        
        $this->updateModificationDate();
    }
 
    /**
     * Delete a Record.  If the specified Record has content that is inherited
     * by other Records, those other Records will not be deleted, but they
     * will no longer have a source from which to inherit value changes.
     * 
     * @param object Id $recordId 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}, {@link }
     *          org.osid.repository.RepositoryException#NULL_ARGUMENT
     *          NULL_ARGUMENT}, {@link }
     *          org.osid.repository.RepositoryException#UNKNOWN_ID UNKNOWN_ID}
     * 
     * @access public
     */
    function deleteRecord ( $recordId ) { 
        ArgumentValidator::validate($recordId, ExtendsValidatorRule::getRule("Id"));
        
        $record =$this->getRecord($recordId);
        $structure =$record->getRecordStructure();
        $structureId =$structure->getId();
        
        // If this is a schema that is hard coded into our implementation, create
        // a record for that schema.
        if (in_array($structureId->getIdString(), array_keys($this->_repository->_builtInTypes))) 
        {
            // Delete all of the Parts for the record
            $parts =$record->getParts();
            while ($parts->hasNext()) {
                $part =$parts->next();
                $record->deletePart($part->getId());
            }
            
            // Delete the relation for the record.
            $dbHandler = Services::getService("DatabaseManager");
            $query = new DeleteQuery;
            $query->setTable("dr_asset_record");
            $myId =$this->getId();
            $query->addWhere("fk_asset = '".$myId->getIdString()."'");
            $query->addWhere("fk_record = '".$recordId->getIdString()."'");
            
            $result =$dbHandler->query($query, $this->_dbIndex);
        }
        // Otherwise use the data manager
        else {
            $recordMgr = Services::getService("RecordManager");
            $record =$recordMgr->fetchRecord($recordId->getIdString(),RECORD_FULL);
            
            // Check if the record is part of other record sets (assets via inheretance)
            $myId =$this->getId();
            $setsContaining = $recordMgr->getRecordSetIDsContaining($record);
            $myRecordSet =$recordMgr->fetchRecordSet($myId->getIdString());
            
            // If this is the last asset referencing this record, delete it.
            $idManager = Services::getService('Id');
            if (count($setsContaining) == 1 && $myId->isEqual($idManager->getId($setsContaining[0]))) {
                $myRecordSet->removeRecord($record);
                $myRecordSet->commit(TRUE);
                $record->delete();
                $record->commit(TRUE);
            }
            // If this record is used by other assets, remove the record from this set, 
            // but leave it in the rest.
            else {
                $myRecordSet =$recordMgr->fetchRecordSet($myId->getIdString());
                $myRecordSet->removeRecord($record);
                $myRecordSet->commit(TRUE);
            }
        }
        
        $this->updateModificationDate();
    }
 
     /**
     * Get the Record for this Asset that matches this Record's unique Id.
     * 
     * @param object Id $recordId 
     *  
     * @return object Record 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}, {@link }
     *          org.osid.repository.RepositoryException#NULL_ARGUMENT
     *          NULL_ARGUMENT}, {@link }
     *          org.osid.repository.RepositoryException#UNKNOWN_ID UNKNOWN_ID}
     * 
     * @access public
     */
    function getRecord ( $recordId ) { 
        ArgumentValidator::validate($recordId, ExtendsValidatorRule::getRule("Id"));
        
        // Check to see if the record is in our cache.
        // If so, return it. If not, create it, then return it.
        if (!isset($this->_createdRecords[$recordId->getIdString()])) {
            // Check for the record in our non-datamanager records;
        
            $idManager = Services::getService("Id");
            $dbHandler = Services::getService("DatabaseManager");
            $myId =$this->getId();
 
            // get the record ids that we want to inherit
            $query = new SelectQuery();
            $query->addTable("dr_asset_record");
            $query->addColumn("structure_id");
            $query->addWhere("fk_asset = '".$myId->getIdString()."'");
            $query->addWhere("fk_record = '".$recordId->getIdString()."'", _AND);
            
            $result =$dbHandler->query($query, $this->_dbIndex);
            
            if ($result->getNumberOfRows()) {
                $structureIdString = $result->field("structure_id");
                
                $recordClass = $this->_repository->_builtInTypes[$structureIdString];
                $recordStructureId =$idManager->getId($structureIdString);
                $recordStructure =$this->_repository->getRecordStructure($recordStructureId);
                
                $this->_createdRecords[$recordId->getIdString()] = new $recordClass(
                                                $recordStructure,
                                                $recordId,
                                                $this->_configuration,
                                                $this
                                            );
            } 
            
            // Otherwise use the data manager
            else {
                
                // Get the DataSet.
                $recordMgr = Services::getService("RecordManager");
                // Specifying TRUE for editable because it is unknown whether or not editing will
                // be needed. @todo Change this if we wish to re-fetch the $dataSet when doing 
                // editing functions.
                $record =$recordMgr->fetchRecord($recordId->getIdString());
    
                // Make sure that we have a valid dataSet
                $rule = ExtendsValidatorRule::getRule("Record");
                if (!$rule->check($record))
                    throwError(new Error(RepositoryException::UNKNOWN_ID(), "Repository :: Asset", TRUE));
                
                // Get the record structure.
                $schema =$record->getSchema();
                if (!isset($this->_createdRecordStructures[$schema->getID()])) {
                    $repository =$this->getRepository();
                    $this->_createdRecordStructures[$schema->getID()] = new HarmoniRecordStructure($schema, $repository->getId());
                }
                
                // Create the Record in our cache.
                $this->_createdRecords[$recordId->getIdString()] = new HarmoniRecord (
                                $this->_createdRecordStructures[$schema->getID()], $record, $this);
            }
            $result->free();
        }
                        
        return $this->_createdRecords[$recordId->getIdString()];
    }
 
    
    /**
     * Get all the Records for this Asset.  Iterators return a set, one at a
     * time.
     *  
     * @return object RecordIterator 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}
     * 
     * @access public
     */
    function getRecords () { 
        
        $id =$this->getId();
        $recordMgr = Services::getService("RecordManager");
        $idManager = Services::getService("Id");        
        $records = array();
        
        // Get the records from the data manager.
        if ($recordSet =$recordMgr->fetchRecordSet($id->getIdString())) {
            // fetching as editable since we don't know if it will be edited.
            $recordSet->loadRecords();
            $dmRecords =$recordSet->getRecords();
    
            // create  records for each dataSet as needed.
            foreach (array_keys($dmRecords) as $key) {
                $recordIdString = $dmRecords[$key]->getID();
                $recordId =$idManager->getId($recordIdString);
                $record =$this->getRecord($recordId);
                $structure =$record->getRecordStructure();
                
                // Add the record to our array
                $records[] =$record;
            }
        }
        
        // get the record ids that we want to inherit
        $dbHandler = Services::getService("DatabaseManager");
        $myId =$this->getId();
        
        $query = new SelectQuery();
        $query->addTable("dr_asset_record");
        $query->addColumn("fk_record");
        $query->addWhere("fk_asset = '".$myId->getIdString()."'");
        
        $result =$dbHandler->query($query, $this->_dbIndex);
        
        while ($result->hasMoreRows()) {
            $recordId =$idManager->getId($result->field("fk_record"));
            
            $records[] =$this->getRecord($recordId);
            
            $result->advanceRow();
        }
        $result->free();
        // Create an iterator and return it.
        $recordIterator = new HarmoniRecordIterator($records);
        
        return $recordIterator;
    }
    
    /**
     * Get all the Records of the specified RecordStructure for this Asset.
     * Iterators return a set, one at a time.
     * 
     * @param object Id $recordStructureId 
     *  
     * @return object RecordIterator 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}, {@link }
     *          org.osid.repository.RepositoryException#NULL_ARGUMENT
     *          NULL_ARGUMENT}, {@link }
     *          org.osid.repository.RepositoryException#UNKNOWN_ID UNKNOWN_ID}
     * 
     * @access public
     */
    function getRecordsByRecordStructure ( $recordStructureId ) { 
        ArgumentValidator::validate($recordStructureId, ExtendsValidatorRule::getRule("Id"));
        
        $id =$this->getId();
        $recordMgr = Services::getService("RecordManager");
        $idManager = Services::getService("Id");        
        $records = array();
        
        // Get our non-datamanager records
        if (in_array($recordStructureId->getIdString(), array_keys($this->_repository->_builtInTypes))) 
        {
            // get the record ids that we want to inherit
            $dbHandler = Services::getService("DatabaseManager");
            $myId =$this->getId();
            
            $query = new SelectQuery();
            $query->addTable("dr_asset_record");
            $query->addColumn("fk_record");
            $query->addWhere("fk_asset = '".$myId->getIdString()."'");
            $query->addWhere("structure_id = '".$recordStructureId->getIdString()."'", _AND);
            
            $result =$dbHandler->query($query, $this->_dbIndex);
            
            while ($result->hasMoreRows()) {
                $recordId =$idManager->getId($result->field("fk_record"));
                
                $records[] =$this->getRecord($recordId);
                
                $result->advanceRow();
            }
            
            $result->free();
        }
        // Get the records from the data manager.
        else if ($recordSet =$recordMgr->fetchRecordSet($id->getIdString())) {
            // fetching as editable since we don't know if it will be edited.
            $recordSet->loadRecords();
            $dmRecords =$recordSet->getRecords();
    
            // create  records for each dataSet as needed.
            foreach (array_keys($dmRecords) as $key) {
                $recordIdString = $dmRecords[$key]->getID();
                $recordId =$idManager->getId($recordIdString);
                $record =$this->getRecord($recordId);
                $structure =$record->getRecordStructure();
                
                // Add the record to our array
                if ($recordStructureId->isEqual($structure->getId()))
                    $records[] =$record;
            }
        }
        
        // Create an iterator and return it.
        $recordIterator = new HarmoniRecordIterator($records);
        
        return $recordIterator;
    }
    
    /**
     * Get all the Records of the specified RecordStructureType for this Asset.
     * Iterators return a set, one at a time.
     * 
     * @param object Type $recordStructureType 
     *  
     * @return object RecordIterator 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}, {@link }
     *          org.osid.repository.RepositoryException#NULL_ARGUMENT
     *          NULL_ARGUMENT}, {@link }
     *          org.osid.repository.RepositoryException#UNKNOWN_ID UNKNOWN_ID}
     * 
     * @access public
     */
    function getRecordsByRecordStructureType ( $recordStructureType ) { 
        throwError(new Error(RepositoryException::UNIMPLEMENTED(), "Repository :: Asset", TRUE));
    } 
     
     /**
     * Get the AssetType of this Asset.  AssetTypes are used to categorize
     * Assets.
     *  
     * @return object Type 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}
     * 
     * @access public
     */
    function getAssetType () { 
        return $this->_node->getType();
    }
 
    /**
     * Get all the RecordStructures for this Asset.  RecordStructures are used
     * to categorize information about Assets.  Iterators return a set, one at
     * a time.
     *  
     * @return object RecordStructureIterator 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}
     * 
     * @access public
     */
    function getRecordStructures () { 
        // cycle through all our DataSets, get their type and make a RecordStructure for each. 
        $recordStructures = array();
        
        $records =$this->getRecords();
        
        while ($records->hasNext()) {
            $record =$records->next();
            $structure =$record->getRecordStructure();
            $structureId =$structure->getId();
            if (!isset($recordStructures[$structureId->getIdString()]))
                $recordStructures[$structureId->getIdString()] =$structure;
        }
        
        $obj = new HarmoniIterator($recordStructures);
        
        return $obj;
    }
 
    /**
     * Get the RecordStructure associated with this Asset's content.
     *  
     * @return object RecordStructure 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}
     * 
     * @access public
     */
    function getContentRecordStructure () { 
        $idManager = Services::getService("Id");
        $schemaMgr = Services::getService("SchemaManager");
        
        $recordStructures =$this->_repository->getRecordStructures();
 
        // Get the id of the Content DataSetTypeDef
        $contentType = "edu.middlebury.harmoni.repository.asset_content";
        $contentTypeId =$idManager->getId($contentType);
        
        while ($recordStructures->hasNext()) {
            $structure =$recordStructures->next();
            if ($contentTypeId->isEqual($structure->getId()))
                return $structure;
        }
        throwError(new Error(RepositoryException::OPERATION_FAILED(), "Repository :: Asset", TRUE));
    }
    
    
    /**
     * Get the Part for a Record for this Asset that matches this Part's unique
     * Id.
     * 
     * @param object Id $partId 
     *  
     * @return object Part 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}, {@link }
     *          org.osid.repository.RepositoryException#NULL_ARGUMENT
     *          NULL_ARGUMENT}, {@link }
     *          org.osid.repository.RepositoryException#UNKNOWN_ID UNKNOWN_ID}
     * 
     * @access public
     */
    function getPart ( $partId ) { 
    
        $records =$this->getRecords();
        while ($records->hasNext()) {
            $record =$records->next();
            $parts =$record->getParts();
            while ($parts->hasNext()) {
                $part =$parts->next();
                if ($partId->isEqual($part->getId()))
                    return $part;
            }
        }
        // Throw an error if we didn't find the part.
        throwError(new Error(RepositoryException::UNKNOWN_ID(), "Repository :: Asset", TRUE));
    }
    
    /**
     * Get the Value of the Part of the Record for this Asset that matches this
     * Part's unique Id.
     * 
     * @param object Id $partId 
     *  
     * @return object mixed (original type: java.io.Serializable)
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}, {@link }
     *          org.osid.repository.RepositoryException#NULL_ARGUMENT
     *          NULL_ARGUMENT}, {@link }
     *          org.osid.repository.RepositoryException#UNKNOWN_ID UNKNOWN_ID}
     * 
     * @access public
     */
    function getPartValue ( $partId ) { 
        $part =$this->getPart($partId);
        return $part->getValue();
    }
    
    /**
     * Get the Parts of the Records for this Asset that are based on this
     * RecordStructure PartStructure's unique Id.
     * 
     * @param object Id $partStructureId 
     *  
     * @return object PartIterator 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}, {@link }
     *          org.osid.repository.RepositoryException#NULL_ARGUMENT
     *          NULL_ARGUMENT}, {@link }
     *          org.osid.repository.RepositoryException#UNKNOWN_ID UNKNOWN_ID}
     * 
     * @access public
     */
    function getPartsByPartStructure ( $partStructureId ) { 
        $returnParts = array();
        $records =$this->getRecords();
        while ($records->hasNext()) {
            $record =$records->next();
            $parts =$record->getParts();
            while ($parts->hasNext()) {
                $part =$parts->next();
                $partStructure =$part->getPartStructure();
                if ($partStructureId->isEqual($partStructure->getId()))
                    $returnParts[] =$part;
            }
        }
        $obj = new HarmoniIterator($returnParts);
        return $obj;
    }
    
    /**
     * Get the Values of the Parts of the Records for this Asset that are based
     * on this RecordStructure PartStructure's unique Id.
     * 
     * @param object Id $partStructureId 
     *  
     * @return object ObjectIterator 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}, {@link }
     *          org.osid.repository.RepositoryException#NULL_ARGUMENT
     *          NULL_ARGUMENT}, {@link }
     *          org.osid.repository.RepositoryException#UNKNOWN_ID UNKNOWN_ID}
     * 
     * @access public
     */
    function getPartValuesByPartStructure ( $partStructureId ) { 
        $partIterator =$this->getPartsByPartStructure($partStructureId);
        $partValues = array();
//        print $partStructureId->getIdString()."<br />";
        while ($partIterator->hasNext()) {
            $part =$partIterator->next();
            $partValues[] =$part->getValue();
        }
        $obj = new HarmoniIterator($partValues);
        return $obj;
    } 
 
    /**
     * Store the effective and expiration Dates. getEffectiveDate or getExpirationDate
     * should be called first to set the datesInDB flag.
     * 
     * @return void 
     * @access public
     * @since 8/10/04
     */
    function _storeDates () {
        $dbHandler = Services::getService("DatabaseManager");
        $id =$this->_node->getId();
        
        // If we have stored dates for this asset set them
        if ($this->_datesInDB) {
            $query = new UpdateQuery;
            $query->addWhereEqual("asset_id", $id->getIdString());
        } 
        
        // Otherwise, insert Them
        else {
            $query = new InsertQuery;
        }
        
        $query->addValue("asset_id", $id->getIdString());
        
        if (is_object($this->_effectiveDate))
            $query->addValue("effective_date", $dbHandler->toDBDate($this->_effectiveDate, $this->_dbIndex));
        else
            $query->addRawValue("effective_date", "NULL");
            
        if (is_object($this->_expirationDate))
            $query->addValue("expiration_date", $dbHandler->toDBDate($this->_expirationDate, $this->_dbIndex));
        else
            $query->addRawValue("expiration_date", "NULL");
            
        if (is_object($this->_createDate) && $this->_createDate->isNotEqualTo(DateAndTime::epoch())) {
            $query->addValue("create_timestamp", $dbHandler->toDBDate($this->_createDate, $this->_dbIndex));
            $query->addRawValue("modify_timestamp", "NOW()");
        } 
        // We are creating the asset.
        else {
            $query->addRawValue("create_timestamp", "NOW()");
            $query->addRawValue("modify_timestamp", "NOW()");
            
            // Add the creator
            $agentId = $this->_getCurrentAgent();
            $query->addValue("creator", $agentId->getIdString());
        }
        
        $query->setTable("dr_asset_info");
        
        $result =$dbHandler->query($query, $this->_dbIndex);
    }
    
    /**
     * Answer the current agent id
     * 
     * @return object Id 
     * @access private
     * @since 7/9/07
     */
    function _getCurrentAgent () {
        $authN = Services::getService("AuthN");
        $agentM = Services::getService("Agent");
        $idM = Services::getService("Id");
        $authTypes =$authN->getAuthenticationTypes();
        
        while ($authTypes->hasNext()) {
            $authType =$authTypes->next();
            $id =$authN->getUserId($authType);
            if (!$id->isEqual($idM->getId('edu.middlebury.agents.anonymous'))) {
                return $id;
            }
        }
        
        // If we didn't find an agent, return the anonymous id.
        return $idM->getId('edu.middlebury.agents.anonymous');
    }
    
    /**
     * Loads dates from the database and sets the _datesInDB flag
     * 
     * @return void 
     * @access public
     * @since 8/10/04
     */
    function _loadDates () {
        $dbHandler = Services::getService("DatabaseManager");
        // Get the content DataSet.
        $id =$this->_node->getId();
        
        $query = new SelectQuery;
        $query->addTable("dr_asset_info");
        $query->addColumn("effective_date");
        $query->addColumn("expiration_date");
        $query->addColumn("create_timestamp");
        $query->addColumn("creator");
        $query->addColumn("modify_timestamp");
        $query->addWhere("asset_id='".$id->getIdString()."'");
        
        $result =$dbHandler->query($query, $this->_dbIndex);
        
        // If we have stored dates for this asset set them
        if ($result->getNumberOfRows()) {
            $this->_effectiveDate =$dbHandler->fromDBDate($result->field("effective_date"), $this->_dbIndex);
            $this->_expirationDate =$dbHandler->fromDBDate($result->field("expiration_date"), $this->_dbIndex);
            $this->_createDate =$dbHandler->fromDBDate($result->field("create_timestamp"), $this->_dbIndex);
            $this->_creator = $result->field("creator");
            $this->_modifyDate =$dbHandler->fromDBDate($result->field("modify_timestamp"), $this->_dbIndex);
            $this->_datesInDB = TRUE;
            
            if (!$this->_createDate)
                $this->_createDate = DateAndTime::epoch();
            if (!$this->_modifyDate)
                $this->_modifyDate = DateAndTime::epoch();
        } 
        
        else {
            $this->_effectiveDate = NULL;
            $this->_expirationDate = NULL;
            $this->_createDate = DateAndTime::epoch();
            $this->_modifyDate = DateAndTime::epoch();
            $this->_creator = NULL;
            $this->_datesInDB = FALSE;
        }
        
        $result->free();
    }
    
    /**
     * Update the modification date and set the creation date if needed.
     *
     * WARNING: NOT IN OSID
     * 
     * @return void 
     * @access public
     * @since 5/4/06
     */
    function updateModificationDate () {
        // Only update our modification time if we will be adding more than a
        // minute (to save on many repeated updates while changing lots of values
        // at once).
        if (isset($this->_modifyDate) && is_object($this->_modifyDate)) {
            $now = DateAndTime::now();
            $minute = Duration::withSeconds(60);
            if ($minute->isGreaterThan($now->minus($this->_modifyDate)))
                return;            
        }
        
        $this->_loadDates();
        $this->_storeDates();
    }
    
    /**
     * Get the date at which this Asset was created.
     *  
     * WARNING: NOT IN OSID
     *
     * @return object DateAndTime 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}
     * 
     * @access public
     */
    function getCreationDate () { 
        if (!isset($this->_createDate) || $this->_createDate->isEqualTo(DateAndTime::epoch())) {
            $this->_loadDates();
        }
        
        return $this->_createDate;
    }
    
    /**
     * Answer the Id of the agent that created the asset
     * 
     * WARNING: NOT IN OSID
     * 
     * @return object Id 
     * @access public
     * @since 7/9/07
     */
    function getCreator () {
        if (!isset($this->_creator)) {
            $this->_loadDates();
        }
        
        if (is_null($this->_creator)) {
            $null = null;
            return $null;
        } else {
            $idManager = Services::getService("Id");
            return $idManager->getId($this->_creator);
        }
    }
    
    /**
     * Get the date at which this Asset was created.
     *  
     * WARNING: NOT IN OSID
     *
     * @return object DateAndTime 
     * 
     * @throws object RepositoryException An exception with one of
     *          the following messages defined in
     *          org.osid.repository.RepositoryException may be thrown: {@link }
     *          org.osid.repository.RepositoryException#OPERATION_FAILED
     *          OPERATION_FAILED}, {@link }
     *          org.osid.repository.RepositoryException#PERMISSION_DENIED
     *          PERMISSION_DENIED}, {@link }
     *          org.osid.repository.RepositoryException#CONFIGURATION_ERROR
     *          CONFIGURATION_ERROR}, {@link }
     *          org.osid.repository.RepositoryException#UNIMPLEMENTED
     *          UNIMPLEMENTED}
     * 
     * @access public
     */
    function getModificationDate () { 
        if (!isset($this->_modifyDate) || $this->_modifyDate->isEqualTo(DateAndTime::epoch())) {
            $this->_loadDates();
        }
        
        return $this->_modifyDate;
    }
    
    /**
     * Saves this object to persistable storage.
     * @access protected
     */
    function save () {        
        // Save the dataManager
        $recordMgr = Services::getService("RecordManager");
        $nodeId =$this->_node->getId();
        $group =$recordMgr->fetchRecordSet($nodeId->getIdString(), true);
        
        // The ignoreMandatory Allows this record to be created without checking for
        // values on mandatory fields. These constraints should be checked when
        // validateAsset() is called.
        if ($group) $group->commit(TRUE);
    }
 
} // end Asset
?>