WorkflowDatabaseTiein/src/definition_storage.php - zetacomponents - Git at Google

 <?php
 /**
  * File containing the ezcWorkflowDatabaseDefinitionStorage class.
  *
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you under the Apache License, Version 2.0 (the
  * "License"); you may not use this file except in compliance
  * with the License.  You may obtain a copy of the License at
  *
  *   http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing,
  * software distributed under the License is distributed on an
  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  * KIND, either express or implied.  See the License for the
  * specific language governing permissions and limitations
  * under the License.
  *
  * @package WorkflowDatabaseTiein
  * @version //autogen//
  * @copyright Copyright (C) 2005-2010 eZ Systems AS. All rights reserved.
  * @license http://www.apache.org/licenses/LICENSE-2.0 Apache License, Version 2.0
  */

 /**
  * Workflow definition storage handler that saves and loads workflow
  * definitions to and from a database.
  *
  * @package WorkflowDatabaseTiein
  * @version //autogen//
  */
 class ezcWorkflowDatabaseDefinitionStorage implements ezcWorkflowDefinitionStorage
 {
     /**
      * ezcDbHandler instance to be used.
      *
      * @var ezcDbHandler
      */
     protected $db;

     /**
      * Container to hold the properties
      *
      * @var array(string=>mixed)
      */
     protected $properties = array(
       'options' => null
     );

     /**
      * Construct a new database definition handler.
      *
      * This constructor is a tie-in.
      *
      * @param ezcDbHandler $db
      */
     public function __construct( ezcDbHandler $db )
     {
         $this->db = $db;
         $this->properties['options'] = new ezcWorkflowDatabaseOptions;
     }

     /**
      * Property get access.
      *
      * @param string $propertyName
      * @return mixed
      * @throws ezcBasePropertyNotFoundException
      *         If the given property could not be found.
      * @ignore
      */
     public function __get( $propertyName )
     {
         switch ( $propertyName )
         {
             case 'options':
                 return $this->properties[$propertyName];
         }

         throw new ezcBasePropertyNotFoundException( $propertyName );
     }

     /**
      * Property set access.
      *
      * @param string $propertyName
      * @param string $propertyValue
      * @throws ezcBasePropertyNotFoundException
      *         If the given property could not be found.
      * @throws ezcBaseValueException
      *         If the value for the property options is not an ezcWorkflowDatabaseOptions object.
      * @ignore
      */
     public function __set( $propertyName, $propertyValue )
     {
         switch ( $propertyName )
         {
             case 'options':
                 if ( !( $propertyValue instanceof ezcWorkflowDatabaseOptions ) )
                 {
                     throw new ezcBaseValueException(
                         $propertyName,
                         $propertyValue,
                         'ezcWorkflowDatabaseOptions'
                     );
                 }
                 break;
             default:
                 throw new ezcBasePropertyNotFoundException( $propertyName );
         }
         $this->properties[$propertyName] = $propertyValue;
     }

     /**
      * Property isset access.
      *
      * @param string $propertyName
      * @return bool
      * @ignore
      */
     public function __isset( $propertyName )
     {
         switch ( $propertyName )
         {
             case 'options':
                 return true;
         }

         return false;
     }

     /**
      * Load a workflow definition by ID.
      *
      * Providing the name of the workflow that is to be loaded as the
      * optional second parameter saves a database query.
      *
      * @param  int $workflowId
      * @param  string  $workflowName
      * @param  int $workflowVersion
      * @return ezcWorkflow
      * @throws ezcWorkflowDefinitionStorageException
      * @throws ezcDbException
      */
     public function loadById( $workflowId, $workflowName = '', $workflowVersion = 0 )
     {
         // Query the database for the name and version of the workflow.
         if ( empty( $workflowName ) || $workflowVersion == 0 )
         {
             $query = $this->db->createSelectQuery();

             $query->select( $this->db->quoteIdentifier( 'workflow_name' ) )
                   ->select( $this->db->quoteIdentifier( 'workflow_version' ) )
                   ->from( $this->db->quoteIdentifier( $this->options['prefix'] . 'workflow' ) )
                   ->where( $query->expr->eq( $this->db->quoteIdentifier( 'workflow_id' ),
                                              $query->bindValue( (int)$workflowId ) ) );

             $stmt = $query->prepare();
             $stmt->execute();

             $result = $stmt->fetchAll( PDO::FETCH_ASSOC );

             if ( $result !== false && isset( $result[0] ) )
             {
                 $workflowName    = $result[0]['workflow_name'];
                 $workflowVersion = $result[0]['workflow_version'];
             }
             else
             {
                 throw new ezcWorkflowDefinitionStorageException(
                   'Could not load workflow definition.'
                 );
             }
         }

         // Query the database for the nodes of the workflow to be loaded.
         $query = $this->db->createSelectQuery();

         $query->select( $this->db->quoteIdentifier( 'node_id' ) )
               ->select( $this->db->quoteIdentifier( 'node_class' ) )
               ->select( $this->db->quoteIdentifier( 'node_configuration' ) )
               ->from( $this->db->quoteIdentifier( $this->options['prefix'] . 'node' ) )
               ->where( $query->expr->eq( $this->db->quoteIdentifier( 'workflow_id' ),
                                           $query->bindValue( (int)$workflowId ) ) );

         $stmt = $query->prepare();
         $stmt->execute();

         $result = $stmt->fetchAll( PDO::FETCH_ASSOC );
         $nodes  = array();

         // Create node objects.
         foreach ( $result as $node )
         {
             $configuration = ezcWorkflowDatabaseUtil::unserialize(
               $node['node_configuration'], null
             );

             if ( is_null( $configuration ) )
             {
                 $configuration = ezcWorkflowUtil::getDefaultConfiguration( $node['node_class'] );
             }

             $nodes[$node['node_id']] = new $node['node_class'](
               $configuration
             );

             if ($nodes[$node['node_id']] instanceof ezcWorkflowNodeFinally &&
                 !isset( $finallyNode ) )
             {
                 $finallyNode = $nodes[$node['node_id']];
             }

             else if ($nodes[$node['node_id']] instanceof ezcWorkflowNodeEnd &&
                      !isset( $defaultEndNode ) )
             {
                 $defaultEndNode = $nodes[$node['node_id']];
             }

             else if ($nodes[$node['node_id']] instanceof ezcWorkflowNodeStart &&
                      !isset( $startNode ) )
             {
                $startNode = $nodes[$node['node_id']];
             }
         }

         if ( !isset( $startNode ) || !isset( $defaultEndNode ) )
         {
             throw new ezcWorkflowDefinitionStorageException(
               'Could not load workflow definition.'
             );
         }

         // Connect node objects.
         $query = $this->db->createSelectQuery();

         $query->select( $query->alias( 'node_connection.incoming_node_id',
                                        $this->db->quoteIdentifier( 'incoming_node_id' ) ) )
               ->select( $query->alias( 'node_connection.outgoing_node_id',
                                        $this->db->quoteIdentifier( 'outgoing_node_id' ) ) )
               ->from( $query->innerJoin( $this->db->quoteIdentifier( $this->options['prefix'] . 'node_connection' ),
                                          $this->db->quoteIdentifier( $this->options['prefix'] . 'node' ),
                                          'node_connection.incoming_node_id',
                                          'node.node_id' ) )
               ->where( $query->expr->eq( 'node.workflow_id',
                                          $query->bindValue( (int)$workflowId ) ) )
               ->orderBy( $this->db->quoteIdentifier( 'node_connection_id' ) );

         $stmt = $query->prepare();
         $stmt->execute();

         $connections = $stmt->fetchAll( PDO::FETCH_ASSOC );

         foreach ( $connections as $connection )
         {
             $nodes[$connection['incoming_node_id']]->addOutNode(
               $nodes[$connection['outgoing_node_id']]
             );
         }

         if ( !isset( $finallyNode ) ||
              count( $finallyNode->getInNodes() ) > 0 )
         {
             $finallyNode = null;
         }

         // Create workflow object and add the node objects to it.
         $workflow = new ezcWorkflow( $workflowName, $startNode, $defaultEndNode, $finallyNode );
         $workflow->definitionStorage = $this;
         $workflow->id = (int)$workflowId;
         $workflow->version = (int)$workflowVersion;

         // Query the database for the variable handlers.
         $query = $this->db->createSelectQuery();

         $query->select( $this->db->quoteIdentifier( 'variable' ) )
               ->select( $this->db->quoteIdentifier( 'class' ) )
               ->from( $this->db->quoteIdentifier( $this->options['prefix'] . 'variable_handler' ) )
               ->where( $query->expr->eq( $this->db->quoteIdentifier( 'workflow_id' ),
                                          $query->bindValue( (int)$workflowId ) ) );

         $stmt = $query->prepare();
         $stmt->execute();

         $result = $stmt->fetchAll( PDO::FETCH_ASSOC );
         $nodes  = array();

         if ( $result !== false )
         {
             foreach ( $result as $variableHandler )
             {
                 $workflow->addVariableHandler(
                   $variableHandler['variable'],
                   $variableHandler['class']
                 );
             }
         }

         // Verify the loaded workflow.
         $workflow->verify();

         return $workflow;
     }

     /**
      * Load a workflow definition by name.
      *
      * @param  string  $workflowName
      * @param  int $workflowVersion
      * @return ezcWorkflow
      * @throws ezcWorkflowDefinitionStorageException
      * @throws ezcDbException
      */
     public function loadByName( $workflowName, $workflowVersion = 0 )
     {
         // Query the database for the workflow ID.
         $query = $this->db->createSelectQuery();

         // Load the current version of the workflow.
         if ( $workflowVersion == 0 )
         {
             $workflowVersion = $this->getCurrentVersionNumber( $workflowName );
         }

         // Query for the workflow_id.
         $query->select( $this->db->quoteIdentifier( 'workflow_id' ) )
               ->from( $this->db->quoteIdentifier( $this->options['prefix'] . 'workflow' ) )
               ->where( $query->expr->eq( $this->db->quoteIdentifier( 'workflow_name' ),
                                          $query->bindValue( $workflowName ) ) )
               ->where( $query->expr->eq( $this->db->quoteIdentifier( 'workflow_version' ),
                                          $query->bindValue( (int)$workflowVersion ) ) );

         $stmt = $query->prepare();
         $stmt->execute();

         $result = $stmt->fetchAll( PDO::FETCH_ASSOC );

         if ( $result !== false && isset( $result[0] ) )
         {
             return $this->loadById(
               $result[0]['workflow_id'],
               $workflowName,
               $workflowVersion
             );
         }
         else
         {
             throw new ezcWorkflowDefinitionStorageException(
               'Could not load workflow definition.'
             );
         }
     }

     /**
      * Save a workflow definition to the database.
      *
      * @param  ezcWorkflow $workflow
      * @throws ezcWorkflowDefinitionStorageException
      * @throws ezcDbException
      */
     public function save( ezcWorkflow $workflow )
     {
         // Verify the workflow.
         $workflow->verify();

         $this->db->beginTransaction();

         // Calculate new version number.
         $workflowVersion = $this->getCurrentVersionNumber( $workflow->name ) + 1;

         // Write workflow table row.
         $query = $this->db->createInsertQuery();

         $query->insertInto( $this->db->quoteIdentifier( $this->options['prefix'] . 'workflow' ) )
               ->set( $this->db->quoteIdentifier( 'workflow_name' ), $query->bindValue( $workflow->name ) )
               ->set( $this->db->quoteIdentifier( 'workflow_version' ), $query->bindValue( (int)$workflowVersion ) )
               ->set( $this->db->quoteIdentifier( 'workflow_created' ), $query->bindValue( time() ) );

         $statement = $query->prepare();
         $statement->execute();

         $workflow->definitionStorage = $this;
         $workflow->id = (int)$this->db->lastInsertId( 'workflow_workflow_id_seq' );
         $workflow->version = (int)$workflowVersion;

         // Write node table rows.
         $nodeMap = array();

         foreach ( $workflow->nodes as $node )
         {
             $query = $this->db->createInsertQuery();

             $query->insertInto( $this->db->quoteIdentifier( $this->options['prefix'] . 'node' ) )
                   ->set( $this->db->quoteIdentifier( 'workflow_id' ), $query->bindValue( (int)$workflow->id ) )
                   ->set( $this->db->quoteIdentifier( 'node_class' ), $query->bindValue( get_class( $node ) ) )
                   ->set( $this->db->quoteIdentifier( 'node_configuration' ), $query->bindValue(
                     ezcWorkflowDatabaseUtil::serialize( $node->getConfiguration() ) )
                   );

             $statement = $query->prepare();
             $statement->execute();

             $nodeMap[$this->db->lastInsertId( $this->db->quoteIdentifier( 'node_node_id_seq' ) )] = $node;
         }

         // Connect node table rows.
         foreach ( $workflow->nodes as $node )
         {
             foreach ( $node->getOutNodes() as $outNode )
             {
                 $incomingNodeId = null;
                 $outgoingNodeId = null;

                 foreach ( $nodeMap as $_id => $_node )
                 {
                     if ( $_node === $node )
                     {
                         $incomingNodeId = $_id;
                     }

                     else if ( $_node === $outNode )
                     {
                         $outgoingNodeId = $_id;
                     }

                     if ( $incomingNodeId !== NULL && $outgoingNodeId !== NULL )
                     {
                         break;
                     }
                 }

                 $query = $this->db->createInsertQuery();

                 $query->insertInto( $this->db->quoteIdentifier( $this->options['prefix'] . 'node_connection' ) )
                       ->set( $this->db->quoteIdentifier( 'incoming_node_id' ), $query->bindValue( $incomingNodeId ) )
                       ->set( $this->db->quoteIdentifier( 'outgoing_node_id' ), $query->bindValue( $outgoingNodeId ) );

                 $statement = $query->prepare();
                 $statement->execute();
             }
         }

         unset( $nodeMap );

         // Write variable handler rows.
         foreach ( $workflow->getVariableHandlers() as $variable => $class )
         {
             $query = $this->db->createInsertQuery();

             $query->insertInto( $this->db->quoteIdentifier( $this->options['prefix'] . 'variable_handler' ) )
                   ->set( $this->db->quoteIdentifier( 'workflow_id' ), $query->bindValue( (int)$workflow->id ) )
                   ->set( $this->db->quoteIdentifier( 'variable' ), $query->bindValue( $variable ) )
                   ->set( $this->db->quoteIdentifier( 'class' ), $query->bindValue( $class ) );

             $statement = $query->prepare();
             $statement->execute();
         }

         $this->db->commit();
     }

     /**
      * Returns the current version number for a given workflow name.
      *
      * @param  string $workflowName
      * @return int
      * @throws ezcDbException
      */
     protected function getCurrentVersionNumber( $workflowName )
     {
         $query = $this->db->createSelectQuery();

         $query->select( $query->alias( $query->expr->max( $this->db->quoteIdentifier( 'workflow_version' ) ),
                                        'version' ) )
               ->from( $this->db->quoteIdentifier( $this->options['prefix'] . 'workflow' ) )
               ->where( $query->expr->eq( $this->db->quoteIdentifier( 'workflow_name' ),
                                          $query->bindValue( $workflowName ) ) );

         $stmt = $query->prepare();
         $stmt->execute();

         $result = $stmt->fetchAll( PDO::FETCH_ASSOC );

         if ( $result !== false && isset( $result[0]['version'] ) && $result[0]['version'] !== null )
         {
             return $result[0]['version'];
         }
         else
         {
             return 0;
         }
     }
 }
 ?>
	<?php
	/**
	* File containing the ezcWorkflowDatabaseDefinitionStorage class.
	*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you under the Apache License, Version 2.0 (the
	* "License"); you may not use this file except in compliance
	* with the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing,
	* software distributed under the License is distributed on an
	* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
	* KIND, either express or implied. See the License for the
	* specific language governing permissions and limitations
	* under the License.
	*
	* @package WorkflowDatabaseTiein
	* @version //autogen//
	* @copyright Copyright (C) 2005-2010 eZ Systems AS. All rights reserved.
	* @license http://www.apache.org/licenses/LICENSE-2.0 Apache License, Version 2.0
	*/

	/**
	* Workflow definition storage handler that saves and loads workflow
	* definitions to and from a database.
	*
	* @package WorkflowDatabaseTiein
	* @version //autogen//
	*/
	class ezcWorkflowDatabaseDefinitionStorage implements ezcWorkflowDefinitionStorage
	{
	/**
	* ezcDbHandler instance to be used.
	*
	* @var ezcDbHandler
	*/
	protected $db;

	/**
	* Container to hold the properties
	*
	* @var array(string=>mixed)
	*/
	protected $properties = array(
	'options' => null
	);

	/**
	* Construct a new database definition handler.
	*
	* This constructor is a tie-in.
	*
	* @param ezcDbHandler $db
	*/
	public function __construct( ezcDbHandler $db )
	{
	$this->db = $db;
	$this->properties['options'] = new ezcWorkflowDatabaseOptions;
	}

	/**
	* Property get access.
	*
	* @param string $propertyName
	* @return mixed
	* @throws ezcBasePropertyNotFoundException
	* If the given property could not be found.
	* @ignore
	*/
	public function __get( $propertyName )
	{
	switch ( $propertyName )
	{
	case 'options':
	return $this->properties[$propertyName];
	}

	throw new ezcBasePropertyNotFoundException( $propertyName );
	}

	/**
	* Property set access.
	*
	* @param string $propertyName
	* @param string $propertyValue
	* @throws ezcBasePropertyNotFoundException
	* If the given property could not be found.
	* @throws ezcBaseValueException
	* If the value for the property options is not an ezcWorkflowDatabaseOptions object.
	* @ignore
	*/
	public function __set( $propertyName, $propertyValue )
	{
	switch ( $propertyName )
	{
	case 'options':
	if ( !( $propertyValue instanceof ezcWorkflowDatabaseOptions ) )
	{
	throw new ezcBaseValueException(
	$propertyName,
	$propertyValue,
	'ezcWorkflowDatabaseOptions'
	);
	}
	break;
	default:
	throw new ezcBasePropertyNotFoundException( $propertyName );
	}
	$this->properties[$propertyName] = $propertyValue;
	}

	/**
	* Property isset access.
	*
	* @param string $propertyName
	* @return bool
	* @ignore
	*/
	public function __isset( $propertyName )
	{
	switch ( $propertyName )
	{
	case 'options':
	return true;
	}

	return false;
	}

	/**
	* Load a workflow definition by ID.
	*
	* Providing the name of the workflow that is to be loaded as the
	* optional second parameter saves a database query.
	*
	* @param int $workflowId
	* @param string $workflowName
	* @param int $workflowVersion
	* @return ezcWorkflow
	* @throws ezcWorkflowDefinitionStorageException
	* @throws ezcDbException
	*/
	public function loadById( $workflowId, $workflowName = '', $workflowVersion = 0 )
	{
	// Query the database for the name and version of the workflow.
	if ( empty( $workflowName ) \|\| $workflowVersion == 0 )
	{
	$query = $this->db->createSelectQuery();

	$query->select( $this->db->quoteIdentifier( 'workflow_name' ) )
	->select( $this->db->quoteIdentifier( 'workflow_version' ) )
	->from( $this->db->quoteIdentifier( $this->options['prefix'] . 'workflow' ) )
	->where( $query->expr->eq( $this->db->quoteIdentifier( 'workflow_id' ),
	$query->bindValue( (int)$workflowId ) ) );

	$stmt = $query->prepare();
	$stmt->execute();

	$result = $stmt->fetchAll( PDO::FETCH_ASSOC );

	if ( $result !== false && isset( $result[0] ) )
	{
	$workflowName = $result[0]['workflow_name'];
	$workflowVersion = $result[0]['workflow_version'];
	}
	else
	{
	throw new ezcWorkflowDefinitionStorageException(
	'Could not load workflow definition.'
	);
	}
	}

	// Query the database for the nodes of the workflow to be loaded.
	$query = $this->db->createSelectQuery();

	$query->select( $this->db->quoteIdentifier( 'node_id' ) )
	->select( $this->db->quoteIdentifier( 'node_class' ) )
	->select( $this->db->quoteIdentifier( 'node_configuration' ) )
	->from( $this->db->quoteIdentifier( $this->options['prefix'] . 'node' ) )
	->where( $query->expr->eq( $this->db->quoteIdentifier( 'workflow_id' ),
	$query->bindValue( (int)$workflowId ) ) );

	$stmt = $query->prepare();
	$stmt->execute();

	$result = $stmt->fetchAll( PDO::FETCH_ASSOC );
	$nodes = array();

	// Create node objects.
	foreach ( $result as $node )
	{
	$configuration = ezcWorkflowDatabaseUtil::unserialize(
	$node['node_configuration'], null
	);

	if ( is_null( $configuration ) )
	{
	$configuration = ezcWorkflowUtil::getDefaultConfiguration( $node['node_class'] );
	}

	$nodes[$node['node_id']] = new $node['node_class'](
	$configuration
	);

	if ($nodes[$node['node_id']] instanceof ezcWorkflowNodeFinally &&
	!isset( $finallyNode ) )
	{
	$finallyNode = $nodes[$node['node_id']];
	}

	else if ($nodes[$node['node_id']] instanceof ezcWorkflowNodeEnd &&
	!isset( $defaultEndNode ) )
	{
	$defaultEndNode = $nodes[$node['node_id']];
	}

	else if ($nodes[$node['node_id']] instanceof ezcWorkflowNodeStart &&
	!isset( $startNode ) )
	{
	$startNode = $nodes[$node['node_id']];
	}
	}

	if ( !isset( $startNode ) \|\| !isset( $defaultEndNode ) )
	{
	throw new ezcWorkflowDefinitionStorageException(
	'Could not load workflow definition.'
	);
	}

	// Connect node objects.
	$query = $this->db->createSelectQuery();

	$query->select( $query->alias( 'node_connection.incoming_node_id',
	$this->db->quoteIdentifier( 'incoming_node_id' ) ) )
	->select( $query->alias( 'node_connection.outgoing_node_id',
	$this->db->quoteIdentifier( 'outgoing_node_id' ) ) )
	->from( $query->innerJoin( $this->db->quoteIdentifier( $this->options['prefix'] . 'node_connection' ),
	$this->db->quoteIdentifier( $this->options['prefix'] . 'node' ),
	'node_connection.incoming_node_id',
	'node.node_id' ) )
	->where( $query->expr->eq( 'node.workflow_id',
	$query->bindValue( (int)$workflowId ) ) )
	->orderBy( $this->db->quoteIdentifier( 'node_connection_id' ) );

	$stmt = $query->prepare();
	$stmt->execute();

	$connections = $stmt->fetchAll( PDO::FETCH_ASSOC );

	foreach ( $connections as $connection )
	{
	$nodes[$connection['incoming_node_id']]->addOutNode(
	$nodes[$connection['outgoing_node_id']]
	);
	}

	if ( !isset( $finallyNode ) \|\|
	count( $finallyNode->getInNodes() ) > 0 )
	{
	$finallyNode = null;
	}

	// Create workflow object and add the node objects to it.
	$workflow = new ezcWorkflow( $workflowName, $startNode, $defaultEndNode, $finallyNode );
	$workflow->definitionStorage = $this;
	$workflow->id = (int)$workflowId;
	$workflow->version = (int)$workflowVersion;

	// Query the database for the variable handlers.
	$query = $this->db->createSelectQuery();

	$query->select( $this->db->quoteIdentifier( 'variable' ) )
	->select( $this->db->quoteIdentifier( 'class' ) )
	->from( $this->db->quoteIdentifier( $this->options['prefix'] . 'variable_handler' ) )
	->where( $query->expr->eq( $this->db->quoteIdentifier( 'workflow_id' ),
	$query->bindValue( (int)$workflowId ) ) );

	$stmt = $query->prepare();
	$stmt->execute();

	$result = $stmt->fetchAll( PDO::FETCH_ASSOC );
	$nodes = array();

	if ( $result !== false )
	{
	foreach ( $result as $variableHandler )
	{
	$workflow->addVariableHandler(
	$variableHandler['variable'],
	$variableHandler['class']
	);
	}
	}

	// Verify the loaded workflow.
	$workflow->verify();

	return $workflow;
	}

	/**
	* Load a workflow definition by name.
	*
	* @param string $workflowName
	* @param int $workflowVersion
	* @return ezcWorkflow
	* @throws ezcWorkflowDefinitionStorageException
	* @throws ezcDbException
	*/
	public function loadByName( $workflowName, $workflowVersion = 0 )
	{
	// Query the database for the workflow ID.
	$query = $this->db->createSelectQuery();

	// Load the current version of the workflow.
	if ( $workflowVersion == 0 )
	{
	$workflowVersion = $this->getCurrentVersionNumber( $workflowName );
	}

	// Query for the workflow_id.
	$query->select( $this->db->quoteIdentifier( 'workflow_id' ) )
	->from( $this->db->quoteIdentifier( $this->options['prefix'] . 'workflow' ) )
	->where( $query->expr->eq( $this->db->quoteIdentifier( 'workflow_name' ),
	$query->bindValue( $workflowName ) ) )
	->where( $query->expr->eq( $this->db->quoteIdentifier( 'workflow_version' ),
	$query->bindValue( (int)$workflowVersion ) ) );

	$stmt = $query->prepare();
	$stmt->execute();

	$result = $stmt->fetchAll( PDO::FETCH_ASSOC );

	if ( $result !== false && isset( $result[0] ) )
	{
	return $this->loadById(
	$result[0]['workflow_id'],
	$workflowName,
	$workflowVersion
	);
	}
	else
	{
	throw new ezcWorkflowDefinitionStorageException(
	'Could not load workflow definition.'
	);
	}
	}

	/**
	* Save a workflow definition to the database.
	*
	* @param ezcWorkflow $workflow
	* @throws ezcWorkflowDefinitionStorageException
	* @throws ezcDbException
	*/
	public function save( ezcWorkflow $workflow )
	{
	// Verify the workflow.
	$workflow->verify();

	$this->db->beginTransaction();

	// Calculate new version number.
	$workflowVersion = $this->getCurrentVersionNumber( $workflow->name ) + 1;

	// Write workflow table row.
	$query = $this->db->createInsertQuery();

	$query->insertInto( $this->db->quoteIdentifier( $this->options['prefix'] . 'workflow' ) )
	->set( $this->db->quoteIdentifier( 'workflow_name' ), $query->bindValue( $workflow->name ) )
	->set( $this->db->quoteIdentifier( 'workflow_version' ), $query->bindValue( (int)$workflowVersion ) )
	->set( $this->db->quoteIdentifier( 'workflow_created' ), $query->bindValue( time() ) );

	$statement = $query->prepare();
	$statement->execute();

	$workflow->definitionStorage = $this;
	$workflow->id = (int)$this->db->lastInsertId( 'workflow_workflow_id_seq' );
	$workflow->version = (int)$workflowVersion;

	// Write node table rows.
	$nodeMap = array();

	foreach ( $workflow->nodes as $node )
	{
	$query = $this->db->createInsertQuery();

	$query->insertInto( $this->db->quoteIdentifier( $this->options['prefix'] . 'node' ) )
	->set( $this->db->quoteIdentifier( 'workflow_id' ), $query->bindValue( (int)$workflow->id ) )
	->set( $this->db->quoteIdentifier( 'node_class' ), $query->bindValue( get_class( $node ) ) )
	->set( $this->db->quoteIdentifier( 'node_configuration' ), $query->bindValue(
	ezcWorkflowDatabaseUtil::serialize( $node->getConfiguration() ) )
	);

	$statement = $query->prepare();
	$statement->execute();

	$nodeMap[$this->db->lastInsertId( $this->db->quoteIdentifier( 'node_node_id_seq' ) )] = $node;
	}

	// Connect node table rows.
	foreach ( $workflow->nodes as $node )
	{
	foreach ( $node->getOutNodes() as $outNode )
	{
	$incomingNodeId = null;
	$outgoingNodeId = null;

	foreach ( $nodeMap as $_id => $_node )
	{
	if ( $_node === $node )
	{
	$incomingNodeId = $_id;
	}

	else if ( $_node === $outNode )
	{
	$outgoingNodeId = $_id;
	}

	if ( $incomingNodeId !== NULL && $outgoingNodeId !== NULL )
	{
	break;
	}
	}

	$query = $this->db->createInsertQuery();

	$query->insertInto( $this->db->quoteIdentifier( $this->options['prefix'] . 'node_connection' ) )
	->set( $this->db->quoteIdentifier( 'incoming_node_id' ), $query->bindValue( $incomingNodeId ) )
	->set( $this->db->quoteIdentifier( 'outgoing_node_id' ), $query->bindValue( $outgoingNodeId ) );

	$statement = $query->prepare();
	$statement->execute();
	}
	}

	unset( $nodeMap );

	// Write variable handler rows.
	foreach ( $workflow->getVariableHandlers() as $variable => $class )
	{
	$query = $this->db->createInsertQuery();

	$query->insertInto( $this->db->quoteIdentifier( $this->options['prefix'] . 'variable_handler' ) )
	->set( $this->db->quoteIdentifier( 'workflow_id' ), $query->bindValue( (int)$workflow->id ) )
	->set( $this->db->quoteIdentifier( 'variable' ), $query->bindValue( $variable ) )
	->set( $this->db->quoteIdentifier( 'class' ), $query->bindValue( $class ) );

	$statement = $query->prepare();
	$statement->execute();
	}

	$this->db->commit();
	}

	/**
	* Returns the current version number for a given workflow name.
	*
	* @param string $workflowName
	* @return int
	* @throws ezcDbException
	*/
	protected function getCurrentVersionNumber( $workflowName )
	{
	$query = $this->db->createSelectQuery();

	$query->select( $query->alias( $query->expr->max( $this->db->quoteIdentifier( 'workflow_version' ) ),
	'version' ) )
	->from( $this->db->quoteIdentifier( $this->options['prefix'] . 'workflow' ) )
	->where( $query->expr->eq( $this->db->quoteIdentifier( 'workflow_name' ),
	$query->bindValue( $workflowName ) ) );

	$stmt = $query->prepare();
	$stmt->execute();

	$result = $stmt->fetchAll( PDO::FETCH_ASSOC );

	if ( $result !== false && isset( $result[0]['version'] ) && $result[0]['version'] !== null )
	{
	return $result[0]['version'];
	}
	else
	{
	return 0;
	}
	}
	}
	?>