Subversion-Projekte lars-tiefland.prado

<?php

/**

 * TActiveRecordRelation class file.

 *

 * @author Wei Zhuo <weizhuo[at]gmail[dot]com>

 * @link http://www.pradosoft.com/

 * @copyright Copyright © 2005-2008 PradoSoft

 * @license http://www.pradosoft.com/license/

 * @version $Id$

 * @package System.Data.ActiveRecord.Relations

 */

/**

 * Load active record relationship context.

 */

Prado::using('System.Data.ActiveRecord.Relations.TActiveRecordRelationContext');

/**

 * Base class for active record relationships.

 *

 * @author Wei Zhuo <weizho[at]gmail[dot]com>

 * @version $Id$

 * @package System.Data.ActiveRecord.Relations

 * @since 3.1

 */

abstract class TActiveRecordRelation

{

	private $_context;

	private $_criteria;

	public function __construct(TActiveRecordRelationContext $context, $criteria)

	{

		$this->_context = $context;

		$this->_criteria = $criteria;

	}

	/**

	 * @return TActiveRecordRelationContext

	 */

	protected function getContext()

	{

		return $this->_context;

	}

	/**

	 * @return TActiveRecordCriteria

	 */

	protected function getCriteria()

	{

		return $this->_criteria;

	}

	/**

	 * @return TActiveRecord

	 */

	protected function getSourceRecord()

	{

		return $this->getContext()->getSourceRecord();

	}

	abstract protected function collectForeignObjects(&$results);

	/**

	 * Dispatch the method calls to the source record finder object. When

	 * an instance of TActiveRecord or an array of TActiveRecord is returned

	 * the corresponding foreign objects are also fetched and assigned.

	 *

	 * Multiple relationship calls can be chain together.

	 *

	 * @param string method name called

	 * @param array method arguments

	 * @return mixed TActiveRecord or array of TActiveRecord results depending on the method called.

	 */

	public function __call($method,$args)

	{

		static $stack=array();

		$results = call_user_func_array(array($this->getSourceRecord(),$method),$args);

		$validArray = is_array($results) && count($results) > 0;

		if($validArray || $results instanceof ArrayAccess || $results instanceof TActiveRecord)

		{

			$this->collectForeignObjects($results);

			while($obj = array_pop($stack))

				$obj->collectForeignObjects($results);

		}

		else if($results instanceof TActiveRecordRelation)

			array_push($stack,$this); //call it later

		return $results;

	}

	/**

	 * Fetch results for current relationship.

	 * @return boolean always true.

	 */

	public function fetchResultsInto($obj)

	{

		$this->collectForeignObjects($obj);

		return true;

	}

	/**

	 * Returns foreign keys in $fromRecord with source column names as key

	 * and foreign column names in the corresponding $matchesRecord as value.

	 * The method returns the first matching foreign key between these 2 records.

	 * @param TActiveRecord $fromRecord

	 * @param TActiveRecord $matchesRecord

	 * @return array foreign keys with source column names as key and foreign column names as value.

	 */

	protected function findForeignKeys($from, $matchesRecord, $loose=false)

	{

		$gateway = $matchesRecord->getRecordGateway();

		$matchingTableName = $gateway->getRecordTableInfo($matchesRecord)->getTableName();

		$tableInfo=$from;

		if($from instanceof TActiveRecord)

			$tableInfo = $gateway->getRecordTableInfo($from);

		//find first non-empty FK

		foreach($tableInfo->getForeignKeys() as $fkeys)

		{

			if(strtolower($fkeys['table'])===strtolower($matchingTableName))

			{

				$hasFkField = !$loose && $this->getContext()->hasFkField();

				$key = $hasFkField ? $this->getFkFields($fkeys['keys']) : $fkeys['keys'];

				if(!empty($key))

					return $key;

			}

		}

		//none found

		$matching = $gateway->getRecordTableInfo($matchesRecord)->getTableFullName();

		throw new TActiveRecordException('ar_relations_missing_fk',

			$tableInfo->getTableFullName(), $matching);

	}

	/**

	 * @return array foreign key field names as key and object properties as value.

	 * @since 3.1.2

	 */

	abstract public function getRelationForeignKeys();

	/**

	 * Find matching foreign key fields from the 3rd element of an entry in TActiveRecord::$RELATION.

	 * Assume field names consist of [\w-] character sets. Prefix to the field names ending with a dot

	 * are ignored.

	 */

	private function getFkFields($fkeys)

	{

		$matching = array();

		preg_match_all('/\s*(\S+\.)?([\w-]+)\s*/', $this->getContext()->getFkField(), $matching);

		$fields = array();

		foreach($fkeys as $fkName => $field)

		{

			if(in_array($fkName, $matching[2]))

				$fields[$fkName] = $field;

		}

		return $fields;

	}

	/**

	 * @param mixed object or array to be hashed

	 * @param array name of property for hashing the properties.

	 * @return string object hash using crc32 and serialize.

	 */

	protected function getObjectHash($obj, $properties)

	{

		$ids=array();

		foreach($properties as $property)

			$ids[] = is_object($obj) ? (string)$obj->getColumnValue($property) : (string)$obj[$property];

		return serialize($ids);

	}

	/**

	 * Fetches the foreign objects using TActiveRecord::findAllByIndex()

	 * @param array field names

	 * @param array foreign key index values.

	 * @return TActiveRecord[] foreign objects.

	 */

	protected function findForeignObjects($fields, $indexValues)

	{

		$finder = $this->getContext()->getForeignRecordFinder();

		return $finder->findAllByIndex($this->_criteria, $fields, $indexValues);

	}

	/**

	 * Obtain the foreign key index values from the results.

	 * @param array property names

	 * @param array TActiveRecord results

	 * @return array foreign key index values.

	 */

	protected function getIndexValues($keys, $results)

	{

		if(!is_array($results) && !$results instanceof ArrayAccess)

			$results = array($results);

		$values=array();

		foreach($results as $result)

		{

			$value = array();

			foreach($keys as $name)

				$value[] = $result->getColumnValue($name);

			$values[] = $value;

		}

		return $values;

	}

	/**

	 * Populate the results with the foreign objects found.

	 * @param array source results

	 * @param array source property names

	 * @param array foreign objects

	 * @param array foreign object field names.

	 */

	protected function populateResult(&$results,$properties,&$fkObjects,$fields)

	{

		$collections=array();

		foreach($fkObjects as $fkObject)

			$collections[$this->getObjectHash($fkObject, $fields)][]=$fkObject;

		$this->setResultCollection($results, $collections, $properties);

	}

	/**

	 * Populates the result array with foreign objects (matched using foreign key hashed property values).

	 * @param array $results

	 * @param array $collections

	 * @param array property names

	 */

	protected function setResultCollection(&$results, &$collections, $properties)

	{

		if(is_array($results) || $results instanceof ArrayAccess)

		{

			for($i=0,$k=count($results);$i<$k;$i++)

				$this->setObjectProperty($results[$i], $properties, $collections);

		}

		else

			$this->setObjectProperty($results, $properties, $collections);

	}

	/**

	 * Sets the foreign objects to the given property on the source object.

	 * @param TActiveRecord source object.

	 * @param array source properties

	 * @param array foreign objects.

	 */

	protected function setObjectProperty($source, $properties, &$collections)

	{

		$hash = $this->getObjectHash($source, $properties);

		$prop = $this->getContext()->getProperty();

		$source->$prop=isset($collections[$hash]) ? $collections[$hash] : array();

	}

}