/cake/cake/libs/model/connection_manager.php

<?php

/* SVN FILE: $Id: connection_manager.php 7847 2008-11-08 02:54:07Z renan.saddam $ */

/**

 * Short description for file.

 *

 * Long description for file

 *

 * PHP versions 4 and 5

 *

 * CakePHP(tm) :  Rapid Development Framework (http://www.cakephp.org)

 * Copyright 2005-2008, Cake Software Foundation, Inc. (http://www.cakefoundation.org)

 *

 * Licensed under The MIT License

 * Redistributions of files must retain the above copyright notice.

 *

 * @filesource

 * @copyright     Copyright 2005-2008, Cake Software Foundation, Inc. (http://www.cakefoundation.org)

 * @link          http://www.cakefoundation.org/projects/info/cakephp CakePHP(tm) Project

 * @package       cake

 * @subpackage    cake.cake.libs.model

 * @since         CakePHP(tm) v 0.10.x.1402

 * @version       $Revision: 7847 $

 * @modifiedby    $LastChangedBy: renan.saddam $

 * @lastmodified  $Date: 2008-11-07 20:54:07 -0600 (Fri, 07 Nov 2008) $

 * @license       http://www.opensource.org/licenses/mit-license.php The MIT License

 */

uses ('model' . DS . 'datasources' . DS . 'datasource');

config('database');



/**

 * Manages loaded instances of DataSource objects

 *

 * Long description for file

 *

 * @package       cake

 * @subpackage    cake.cake.libs.model

 */

class ConnectionManager extends Object {

/**

 * Holds a loaded instance of the Connections object

 *

 * @var object

 * @access public

 */

	var $config = null;

/**

 * Holds instances DataSource objects

 *

 * @var array

 * @access protected

 */

	var $_dataSources = array();

/**

 * Contains a list of all file and class names used in Connection settings

 *

 * @var array

 * @access protected

 */

	var $_connectionsEnum = array();

/**

 * Constructor.

 *

 */

	function __construct() {

		if (class_exists('DATABASE_CONFIG')) {

			$this->config =& new DATABASE_CONFIG();

		}

	}

/**

 * Gets a reference to the ConnectionManger object instance

 *

 * @return object Instance

 * @access public

 * @static

 */

	function &getInstance() {

		static $instance = array();



		if (!$instance) {

			$instance[0] =& new ConnectionManager();

		}



		return $instance[0];

	}

/**

 * Gets a reference to a DataSource object

 *

 * @param string $name The name of the DataSource, as defined in app/config/connections

 * @return object Instance

 * @access public

 * @static

 */

	function &getDataSource($name) {

		$_this =& ConnectionManager::getInstance();



		if (!empty($_this->_dataSources[$name])) {

			$return =& $_this->_dataSources[$name];

			return $return;

		}



		$connections = $_this->enumConnectionObjects();

		if (!empty($connections[$name])) {

			$conn = $connections[$name];

			$class = $conn['classname'];

			$_this->loadDataSource($name);

			$_this->_dataSources[$name] =& new $class($_this->config->{$name});

			$_this->_dataSources[$name]->configKeyName = $name;

		} else {

			trigger_error(sprintf(__("ConnectionManager::getDataSource - Non-existent data source %s", true), $name), E_USER_ERROR);

			return null;

		}



		$return =& $_this->_dataSources[$name];

		return $return;

	}

/**

 * Gets the list of available DataSource connections

 *

 * @return array List of available connections

 * @access public

 * @static

 */

	function sourceList() {

		$_this =& ConnectionManager::getInstance();

		return array_keys($_this->_dataSources);

	}

/**

 * Gets a DataSource name from an object reference

 *

 * @param object $source DataSource object

 * @return string Datasource name

 * @access public

 * @static

 */

	function getSourceName(&$source) {

		$_this =& ConnectionManager::getInstance();

		$names = array_keys($_this->_dataSources);

		for ($i = 0; $i < count($names); $i++) {

			if ($_this->_dataSources[$names[$i]] === $source) {

				return $names[$i];

			}

		}

		return null;

	}

/**

 * Loads the DataSource class for the given connection name

 *

 * @param mixed $connName A string name of the connection, as defined in Connections config,

 *                        or an array containing the file and class name of the object.

 * @return boolean True on success, null on failure or false if the class is already loaded

 * @access public

 * @static

 */

	function loadDataSource($connName) {

		$_this =& ConnectionManager::getInstance();



		if (is_array($connName)) {

			$conn = $connName;

		} else {

			$connections = $_this->enumConnectionObjects();

			$conn = $connections[$connName];

		}



		if (!empty($conn['parent'])) {

			$_this->loadDataSource($conn['parent']);

		}



		if (class_exists($conn['classname'])) {

			return false;

		}



		if (file_exists(MODELS . 'datasources' . DS . $conn['filename'] . '.php')) {

			require (MODELS . 'datasources' . DS . $conn['filename'] . '.php');

		} elseif (fileExistsInPath(LIBS . 'model' . DS . 'datasources' . DS . $conn['filename'] . '.php')) {

			require (LIBS . 'model' . DS . 'datasources' . DS . $conn['filename'] . '.php');

		} else {

			trigger_error(sprintf(__('Unable to load DataSource file %s.php', true), $conn['filename']), E_USER_ERROR);

			return null;

		}

	}

/**

 * Gets a list of class and file names associated with the user-defined DataSource connections

 *

 * @return array An associative array of elements where the key is the connection name

 *               (as defined in Connections), and the value is an array with keys 'filename' and 'classname'.

 * @access public

 * @static

 */

	function enumConnectionObjects() {

		$_this =& ConnectionManager::getInstance();



		if (!empty($_this->_connectionsEnum)) {

			return $_this->_connectionsEnum;

		}

		$connections = get_object_vars($_this->config);



		if ($connections != null) {

			foreach ($connections as $name => $config) {

				$_this->_connectionsEnum[$name] = $_this->__getDriver($config);

			}

			return $_this->_connectionsEnum;

		} else {

			$_this->cakeError('missingConnection', array(array('className' => 'ConnectionManager')));

		}

	}

/**

 * Dynamically creates a DataSource object at runtime, with the given name and settings

 *

 * @param string $name The DataSource name

 * @param array $config The DataSource configuration settings

 * @return object A reference to the DataSource object, or null if creation failed

 * @access public

 * @static

 */

	function &create($name = '', $config = array()) {

		$_this =& ConnectionManager::getInstance();



		if (empty($name) || empty($config) || array_key_exists($name, $_this->_connectionsEnum)) {

			$null = null;

			return $null;

		}



		$_this->config->{$name} = $config;

		$_this->_connectionsEnum[$name] = $_this->__getDriver($config);

		$return =& $_this->getDataSource($name);

		return $return;

	}

/**

 * Returns the file, class name, and parent for the given driver.

 *

 * @return array An indexed array with: filename, classname, and parent

 * @access private

 */

	function __getDriver($config) {

		if (!isset($config['datasource'])) {

			$config['datasource'] = 'dbo';

		}



		if (isset($config['driver']) && $config['driver'] != null && !empty($config['driver'])) {

			$filename = $config['datasource'] . DS . $config['datasource'] . '_' . $config['driver'];

			$classname = Inflector::camelize(strtolower($config['datasource'] . '_' . $config['driver']));

			$parent = $this->__getDriver(array('datasource' => $config['datasource']));

		} else {

			$filename = $config['datasource'] . '_source';

			$classname = Inflector::camelize(strtolower($config['datasource'] . '_source'));

			$parent = null;

		}

		return array('filename'  => $filename, 'classname' => $classname, 'parent' => $parent);

	}

/**

 * Destructor.

 *

 * @access private

 */

	function __destruct() {

		if (Configure::read('Session.save') == 'database' && function_exists('session_write_close')) {

			session_write_close();

		}

	}

}

?>