Subversion-Projekte lars-tiefland.prado

<?php
/**
 * TActiveRecordBelongsTo class file.
 *
 * @author Wei Zhuo <weizhuo[at]gmail[dot]com>
 * @link http://www.pradosoft.com/
 * @copyright Copyright &copy; 2005-2008 PradoSoft
 * @license http://www.pradosoft.com/license/
 * @version $Id$
 * @package System.Data.ActiveRecord.Relations
 */

/**
 * Loads base active record relationship class.
 */
Prado::using('System.Data.ActiveRecord.Relations.TActiveRecordRelation');

/**
 * Implements the foreign key relationship (TActiveRecord::BELONGS_TO) between
 * the source objects and the related foreign object. Consider the
 * <b>entity</b> relationship between a Team and a Player.
 * <code>
 * +------+            +--------+
 * | Team | 1 <----- * | Player |
 * +------+            +--------+
 * </code>
 * Where one team may have 0 or more players and each player belongs to only
 * one team. We may model Team-Player <b>object</b> relationship as active record as follows.
 * <code>
 * class TeamRecord extends TActiveRecord
 * {
 *     // see TActiveRecordHasMany for detailed definition.
 * }
 * class PlayerRecord extends TActiveRecord
 * {
 *     const TABLE='player';
 *     public $player_id; //primary key
 *     public $team_name; //foreign key player.team_name <-> team.name
 *         public $age;
 *     public $team; //foreign object TeamRecord
 *
 *     public static $RELATIONS = array
 *     (
 *                      'team' => array(self::BELONGS_TO, 'TeamRecord')
 *     );
 *
 *         public static function finder($className=__CLASS__)
 *         {
 *                 return parent::finder($className);
 *         }
 * }
 * </code>
 * The static <tt>$RELATIONS</tt> property of PlayerRecord defines that the
 * property <tt>$team</tt> belongs to a <tt>TeamRecord</tt>.
 *
 * The team object may be fetched as follows.
 * <code>
 * $players = PlayerRecord::finder()->with_team()->findAll();
 * </code>
 * The method <tt>with_xxx()</tt> (where <tt>xxx</tt> is the relationship property
 * name, in this case, <tt>team</tt>) fetchs the corresponding TeamRecords using
 * a second query (not by using a join). The <tt>with_xxx()</tt> accepts the same
 * arguments as other finder methods of TActiveRecord, e.g.
 * <tt>with_team('location = ?', 'Madrid')</tt>.
 *
 * @author Wei Zhuo <weizho[at]gmail[dot]com>
 * @version $Id$
 * @package System.Data.ActiveRecord.Relations
 * @since 3.1
 */
class TActiveRecordBelongsTo extends TActiveRecordRelation
{
        /**
         * Get the foreign key index values from the results and make calls to the
         * database to find the corresponding foreign objects.
         * @param array original results.
         */
        protected function collectForeignObjects(&$results)
        {
                $fkeys = $this->getRelationForeignKeys();

                $properties = array_keys($fkeys);
                $fields = array_values($fkeys);
                $indexValues = $this->getIndexValues($properties, $results);
                $fkObjects = $this->findForeignObjects($fields, $indexValues);
                $this->populateResult($results,$properties,$fkObjects,$fields);
        }

        /**
         * @return array foreign key field names as key and object properties as value.
         * @since 3.1.2
         */
        public function getRelationForeignKeys()
        {
                $fkObject = $this->getContext()->getForeignRecordFinder();
                return $this->findForeignKeys($this->getSourceRecord(),$fkObject);
        }

        /**
         * Sets the foreign objects to the given property on the source object.
         * @param TActiveRecord source object.
         * @param array foreign objects.
         */
        protected function setObjectProperty($source, $properties, &$collections)
        {
                $hash = $this->getObjectHash($source, $properties);
                $prop = $this->getContext()->getProperty();
                if(isset($collections[$hash]) && count($collections[$hash]) > 0)
                {
                        if(count($collections[$hash]) > 1)
                                throw new TActiveRecordException('ar_belongs_to_multiple_result');
                        $source->$prop=$collections[$hash][0];
                }
                else
                        $source->$prop=null;
        }

        /**
         * Updates the source object first.
         * @return boolean true if all update are success (including if no update was required), false otherwise .
         */
        public function updateAssociatedRecords()
        {
                $obj = $this->getContext()->getSourceRecord();
                $fkObject = $obj->getColumnValue($this->getContext()->getProperty());
                if($fkObject!==null)
                {
                        $fkObject->save();
                        $source = $this->getSourceRecord();
                        $fkeys = $this->findForeignKeys($source, $fkObject);
                        foreach($fkeys as $srcKey => $fKey)
                                $source->setColumnValue($srcKey, $fkObject->getColumnValue($fKey));
                        return true;
                }
                return false;
        }
}