WebSVN – lars-tiefland.prado – /framework/Data/ActiveRecord/Relations/TActiveRecordHasManyAssociation.php

<?php
/**
 * TActiveRecordHasManyAssociation 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 relations class.
 */
Prado::using('System.Data.ActiveRecord.Relations.TActiveRecordRelation');

/**
 * Implements the M-N (many to many) relationship via association table.
 * Consider the <b>entity</b> relationship between Articles and Categories
 * via the association table <tt>Article_Category</tt>.
 * <code>
 * +---------+            +------------------+            +----------+
 * | Article | * -----> * | Article_Category | * <----- * | Category |
 * +---------+            +------------------+            +----------+
 * </code>
 * Where one article may have 0 or more categories and each category may have 0
 * or more articles. We may model Article-Category <b>object</b> relationship
 * as active record as follows.
 * <code>
 * class ArticleRecord
 * {
 *     const TABLE='Article';
 *     public $article_id;
 *
 *     public $Categories=array(); //foreign object collection.
 *
 *     public static $RELATIONS = array
 *     (
 *         'Categories' => array(self::MANY_TO_MANY, 'CategoryRecord', 'Article_Category')
 *     );
 *
 *     public static function finder($className=__CLASS__)
 *     {
 *         return parent::finder($className);
 *     }
 * }
 * class CategoryRecord
 * {
 *     const TABLE='Category';
 *     public $category_id;
 *
 *     public $Articles=array();
 *
 *     public static $RELATIONS = array
 *     (
 *         'Articles' => array(self::MANY_TO_MANY, 'ArticleRecord', 'Article_Category')
 *     );
 *
 *     public static function finder($className=__CLASS__)
 *     {
 *         return parent::finder($className);
 *     }
 * }
 * </code>
 *
 * The static <tt>$RELATIONS</tt> property of ArticleRecord defines that the
 * property <tt>$Categories</tt> has many <tt>CategoryRecord</tt>s. Similar, the
 * static <tt>$RELATIONS</tt> property of CategoryRecord defines many ArticleRecords.
 *
 * The articles with categories list may be fetched as follows.
 * <code>
 * $articles = TeamRecord::finder()->withCategories()->findAll();
 * </code>
 * The method <tt>with_xxx()</tt> (where <tt>xxx</tt> is the relationship property
 * name, in this case, <tt>Categories</tt>) fetchs the corresponding CategoryRecords using
 * a second query (not by using a join). The <tt>with_xxx()</tt> accepts the same
 * arguments as other finder methods of TActiveRecord.
 *
 * @author Wei Zhuo <weizho[at]gmail[dot]com>
 * @version $Id$
 * @package System.Data.ActiveRecord.Relations
 * @since 3.1
 */
class TActiveRecordHasManyAssociation extends TActiveRecordRelation
{
        private $_association;
        private $_sourceTable;
        private $_foreignTable;
        private $_association_columns=array();

        /**
        * Get the foreign key index values from the results and make calls to the
        * database to find the corresponding foreign objects using association table.
        * @param array original results.
        */
        protected function collectForeignObjects(&$results)
        {
                list($sourceKeys, $foreignKeys) = $this->getRelationForeignKeys();
                $properties = array_values($sourceKeys);
                $indexValues = $this->getIndexValues($properties, $results);
                $this->fetchForeignObjects($results, $foreignKeys,$indexValues,$sourceKeys);
        }

        /**
         * @return array 2 arrays of source keys and foreign keys from the association table.
         */
        public function getRelationForeignKeys()
        {
                $association = $this->getAssociationTable();
                $sourceKeys = $this->findForeignKeys($association, $this->getSourceRecord(), true);
                $fkObject = $this->getContext()->getForeignRecordFinder();
                $foreignKeys = $this->findForeignKeys($association, $fkObject);
                return array($sourceKeys, $foreignKeys);
        }

        /**
         * @return TDbTableInfo association table information.
         */
        protected function getAssociationTable()
        {
                if($this->_association===null)
                {
                        $gateway = $this->getSourceRecord()->getRecordGateway();
                        $conn = $this->getSourceRecord()->getDbConnection();
                        //table name may include the fk column name separated with a dot.
                        $table = explode('.', $this->getContext()->getAssociationTable());
                        if(count($table)>1)
                        {
                                $columns = preg_replace('/^\((.*)\)/', '\1', $table[1]);
                                $this->_association_columns = preg_split('/\s*[, ]\*/',$columns);
                        }
                        $this->_association = $gateway->getTableInfo($conn, $table[0]);
                }
                return $this->_association;
        }

        /**
         * @return TDbTableInfo source table information.
         */
        protected function getSourceTable()
        {
                if($this->_sourceTable===null)
                {
                        $gateway = $this->getSourceRecord()->getRecordGateway();
                        $this->_sourceTable = $gateway->getRecordTableInfo($this->getSourceRecord());
                }
                return $this->_sourceTable;
        }

        /**
         * @return TDbTableInfo foreign table information.
         */
        protected function getForeignTable()
        {
                if($this->_foreignTable===null)
                {
                        $gateway = $this->getSourceRecord()->getRecordGateway();
                        $fkObject = $this->getContext()->getForeignRecordFinder();
                        $this->_foreignTable = $gateway->getRecordTableInfo($fkObject);
                }
                return $this->_foreignTable;
        }

        /**
         * @return TDataGatewayCommand
         */
        protected function getCommandBuilder()
        {
                return $this->getSourceRecord()->getRecordGateway()->getCommand($this->getSourceRecord());
        }

        /**
         * @return TDataGatewayCommand
         */
        protected function getForeignCommandBuilder()
        {
                $obj = $this->getContext()->getForeignRecordFinder();
                return $this->getSourceRecord()->getRecordGateway()->getCommand($obj);
        }


        /**
         * Fetches the foreign objects using TActiveRecord::findAllByIndex()
         * @param array field names
         * @param array foreign key index values.
         */
        protected function fetchForeignObjects(&$results,$foreignKeys,$indexValues,$sourceKeys)
        {
                $criteria = $this->getCriteria();
                $finder = $this->getContext()->getForeignRecordFinder();
                $type = get_class($finder);
                $command = $this->createCommand($criteria, $foreignKeys,$indexValues,$sourceKeys);
                $srcProps = array_keys($sourceKeys);
                $collections=array();
                foreach($this->getCommandBuilder()->onExecuteCommand($command, $command->query()) as $row)
                {
                        $hash = $this->getObjectHash($row, $srcProps);
                        foreach($srcProps as $column)
                                unset($row[$column]);
                        $obj = $this->createFkObject($type,$row,$foreignKeys);
                        $collections[$hash][] = $obj;
                }
                $this->setResultCollection($results, $collections, array_values($sourceKeys));
        }

        /**
         * @param string active record class name.
         * @param array row data
         * @param array foreign key column names
         * @return TActiveRecord
         */
        protected function createFkObject($type,$row,$foreignKeys)
        {
                $obj = TActiveRecord::createRecord($type, $row);
                if(count($this->_association_columns) > 0)
                {
                        $i=0;
                        foreach($foreignKeys as $ref=>$fk)
                                $obj->setColumnValue($ref, $row[$this->_association_columns[$i++]]);
                }
                return $obj;
        }

        /**
         * @param TSqlCriteria
         * @param TTableInfo association table info
         * @param array field names
         * @param array field values
         */
        public function createCommand($criteria, $foreignKeys,$indexValues,$sourceKeys)
        {
                $innerJoin = $this->getAssociationJoin($foreignKeys,$indexValues,$sourceKeys);
                $fkTable = $this->getForeignTable()->getTableFullName();
                $srcColumns = $this->getSourceColumns($sourceKeys);
                if(($where=$criteria->getCondition())===null)
                        $where='1=1';
                $sql = "SELECT {$fkTable}.*, {$srcColumns} FROM {$fkTable} {$innerJoin} WHERE {$where}";

                $parameters = $criteria->getParameters()->toArray();
                $ordering = $criteria->getOrdersBy();
                $limit = $criteria->getLimit();
                $offset = $criteria->getOffset();

                $builder = $this->getForeignCommandBuilder()->getBuilder();
                $command = $builder->applyCriterias($sql,$parameters,$ordering,$limit,$offset);
                $this->getCommandBuilder()->onCreateCommand($command, $criteria);
                return $command;
        }

        /**
         * @param array source table column names.
         * @return string comma separated source column names.
         */
        protected function getSourceColumns($sourceKeys)
        {
                $columns=array();
                $table = $this->getAssociationTable();
                $tableName = $table->getTableFullName();
                $columnNames = array_merge(array_keys($sourceKeys),$this->_association_columns);
                foreach($columnNames as $name)
                        $columns[] = $tableName.'.'.$table->getColumn($name)->getColumnName();
                return implode(', ', $columns);
        }

        /**
         * SQL inner join for M-N relationship via association table.
         * @param array foreign table column key names.
         * @param array source table index values.
         * @param array source table column names.
         * @return string inner join condition for M-N relationship via association table.
         */
        protected function getAssociationJoin($foreignKeys,$indexValues,$sourceKeys)
        {
                $refInfo= $this->getAssociationTable();
                $fkInfo = $this->getForeignTable();

                $refTable = $refInfo->getTableFullName();
                $fkTable = $fkInfo->getTableFullName();

                $joins = array();
                $hasAssociationColumns = count($this->_association_columns) > 0;
                $i=0;
                foreach($foreignKeys as $ref=>$fk)
                {
                        if($hasAssociationColumns)
                                $refField = $refInfo->getColumn($this->_association_columns[$i++])->getColumnName();
                        else
                                $refField = $refInfo->getColumn($ref)->getColumnName();
                        $fkField = $fkInfo->getColumn($fk)->getColumnName();
                        $joins[] = "{$fkTable}.{$fkField} = {$refTable}.{$refField}";
                }
                $joinCondition = implode(' AND ', $joins);
                $index = $this->getCommandBuilder()->getIndexKeyCondition($refInfo,array_keys($sourceKeys), $indexValues);
                return "INNER JOIN {$refTable} ON ({$joinCondition}) AND {$index}";
        }

        /**
         * Updates the associated foreign objects.
         * @return boolean true if all update are success (including if no update was required), false otherwise .
         */
        public function updateAssociatedRecords()
        {
                $obj = $this->getContext()->getSourceRecord();
                $fkObjects = &$obj->{$this->getContext()->getProperty()};
                $success=true;
                if(($total = count($fkObjects))> 0)
                {
                        $source = $this->getSourceRecord();
                        $builder = $this->getAssociationTableCommandBuilder();
                        for($i=0;$i<$total;$i++)
                                $success = $fkObjects[$i]->save() && $success;
                        return $this->updateAssociationTable($obj, $fkObjects, $builder) && $success;
                }
                return $success;
        }

        /**
         * @return TDbCommandBuilder
         */
        protected function getAssociationTableCommandBuilder()
        {
                $conn = $this->getContext()->getSourceRecord()->getDbConnection();
                return $this->getAssociationTable()->createCommandBuilder($conn);
        }

        private function hasAssociationData($builder,$data)
        {
                $condition=array();
                $table = $this->getAssociationTable();
                foreach($data as $name=>$value)
                        $condition[] = $table->getColumn($name)->getColumnName().' = ?';
                $command = $builder->createCountCommand(implode(' AND ', $condition),array_values($data));
                $result = $this->getCommandBuilder()->onExecuteCommand($command, intval($command->queryScalar()));
                return intval($result) > 0;
        }

        private function addAssociationData($builder,$data)
        {
                $command = $builder->createInsertCommand($data);
                return $this->getCommandBuilder()->onExecuteCommand($command, $command->execute()) > 0;
        }

        private function updateAssociationTable($obj,$fkObjects, $builder)
        {
                $source = $this->getSourceRecordValues($obj);
                $foreignKeys = $this->findForeignKeys($this->getAssociationTable(), $fkObjects[0]);
                $success=true;
                foreach($fkObjects as $fkObject)
                {
                        $data = array_merge($source, $this->getForeignObjectValues($foreignKeys,$fkObject));
                        if(!$this->hasAssociationData($builder,$data))
                                $success = $this->addAssociationData($builder,$data) && $success;
                }
                return $success;
        }

        private function getSourceRecordValues($obj)
        {
                $sourceKeys = $this->findForeignKeys($this->getAssociationTable(), $obj);
                $indexValues = $this->getIndexValues(array_values($sourceKeys), $obj);
                $data = array();
                $i=0;
                foreach($sourceKeys as $name=>$srcKey)
                        $data[$name] = $indexValues[0][$i++];
                return $data;
        }

        private function getForeignObjectValues($foreignKeys,$fkObject)
        {
                $data=array();
                foreach($foreignKeys as $name=>$fKey)
                        $data[$name] = $fkObject->getColumnValue($fKey);
                return $data;
        }
}
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(root)/framework/Data/ActiveRecord/Relations/TActiveRecordHasManyAssociation.php @ 9 – Revision 1
