Subversion Repositories SmartDukaan

<?php
/**
 * Datasource connection manager
 *
 * Provides an interface for loading and enumerating connections defined in app/Config/database.php
 *
 * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
 * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 *
 * Licensed under The MIT License
 * For full copyright and license information, please see the LICENSE.txt
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 * @link          http://cakephp.org CakePHP(tm) Project
 * @package       Cake.Model
 * @since         CakePHP(tm) v 0.10.x.1402
 * @license       http://www.opensource.org/licenses/mit-license.php MIT License
 */

App::uses('DataSource', 'Model/Datasource');

/**
 * Manages loaded instances of DataSource objects
 *
 * Provides an interface for loading and enumerating connections defined in
 * app/Config/database.php
 *
 * @package       Cake.Model
 */
class ConnectionManager {

/**
 * Holds a loaded instance of the Connections object
 *
 * @var DATABASE_CONFIG
 */
        public static $config = null;

/**
 * Holds instances DataSource objects
 *
 * @var array
 */
        protected static $_dataSources = array();

/**
 * Contains a list of all file and class names used in Connection settings
 *
 * @var array
 */
        protected static $_connectionsEnum = array();

/**
 * Indicates if the init code for this class has already been executed
 *
 * @var bool
 */
        protected static $_init = false;

/**
 * Loads connections configuration.
 *
 * @return void
 */
        protected static function _init() {
                include_once APP . 'Config' . DS . 'database.php';
                if (class_exists('DATABASE_CONFIG')) {
                        static::$config = new DATABASE_CONFIG();
                }
                static::$_init = true;
        }

/**
 * Gets a reference to a DataSource object
 *
 * @param string $name The name of the DataSource, as defined in app/Config/database.php
 * @return DataSource Instance
 * @throws MissingDatasourceException
 */
        public static function getDataSource($name) {
                if (empty(static::$_init)) {
                        static::_init();
                }

                if (!empty(static::$_dataSources[$name])) {
                        return static::$_dataSources[$name];
                }

                if (empty(static::$_connectionsEnum[$name])) {
                        static::_getConnectionObject($name);
                }

                static::loadDataSource($name);
                $conn = static::$_connectionsEnum[$name];
                $class = $conn['classname'];

                if (strpos(App::location($class), 'Datasource') === false) {
                        throw new MissingDatasourceException(array(
                                'class' => $class,
                                'plugin' => null,
                                'message' => 'Datasource is not found in Model/Datasource package.'
                        ));
                }
                static::$_dataSources[$name] = new $class(static::$config->{$name});
                static::$_dataSources[$name]->configKeyName = $name;

                return static::$_dataSources[$name];
        }

/**
 * Gets the list of available DataSource connections
 * This will only return the datasources instantiated by this manager
 * It differs from enumConnectionObjects, since the latter will return all configured connections
 *
 * @return array List of available connections
 */
        public static function sourceList() {
                if (empty(static::$_init)) {
                        static::_init();
                }
                return array_keys(static::$_dataSources);
        }

/**
 * Gets a DataSource name from an object reference.
 *
 * @param DataSource $source DataSource object
 * @return string|null Datasource name, or null if source is not present
 *    in the ConnectionManager.
 */
        public static function getSourceName($source) {
                if (empty(static::$_init)) {
                        static::_init();
                }
                foreach (static::$_dataSources as $name => $ds) {
                        if ($ds === $source) {
                                return $name;
                        }
                }
                return null;
        }

/**
 * Loads the DataSource class for the given connection name
 *
 * @param string|array $connName A string name of the connection, as defined in app/Config/database.php,
 *    or an array containing the filename (without extension) and class name of the object,
 *    to be found in app/Model/Datasource/ or lib/Cake/Model/Datasource/.
 * @return bool True on success, null on failure or false if the class is already loaded
 * @throws MissingDatasourceException
 */
        public static function loadDataSource($connName) {
                if (empty(static::$_init)) {
                        static::_init();
                }

                if (is_array($connName)) {
                        $conn = $connName;
                } else {
                        $conn = static::$_connectionsEnum[$connName];
                }

                if (class_exists($conn['classname'], false)) {
                        return false;
                }

                $plugin = $package = null;
                if (!empty($conn['plugin'])) {
                        $plugin = $conn['plugin'] . '.';
                }
                if (!empty($conn['package'])) {
                        $package = '/' . $conn['package'];
                }

                App::uses($conn['classname'], $plugin . 'Model/Datasource' . $package);
                if (!class_exists($conn['classname'])) {
                        throw new MissingDatasourceException(array(
                                'class' => $conn['classname'],
                                'plugin' => substr($plugin, 0, -1)
                        ));
                }
                return true;
        }

/**
 * Returns a list of 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'.
 */
        public static function enumConnectionObjects() {
                if (empty(static::$_init)) {
                        static::_init();
                }
                return (array)static::$config;
        }

/**
 * Dynamically creates a DataSource object at runtime, with the given name and settings
 *
 * @param string $name The DataSource name
 * @param array $config The DataSource configuration settings
 * @return DataSource|null A reference to the DataSource object, or null if creation failed
 */
        public static function create($name = '', $config = array()) {
                if (empty(static::$_init)) {
                        static::_init();
                }

                if (empty($name) || empty($config) || array_key_exists($name, static::$_connectionsEnum)) {
                        return null;
                }
                static::$config->{$name} = $config;
                static::$_connectionsEnum[$name] = static::_connectionData($config);
                $return = static::getDataSource($name);
                return $return;
        }

/**
 * Removes a connection configuration at runtime given its name
 *
 * @param string $name the connection name as it was created
 * @return bool success if connection was removed, false if it does not exist
 */
        public static function drop($name) {
                if (empty(static::$_init)) {
                        static::_init();
                }

                if (!isset(static::$config->{$name})) {
                        return false;
                }
                unset(static::$_connectionsEnum[$name], static::$_dataSources[$name], static::$config->{$name});
                return true;
        }

/**
 * Gets a list of class and file names associated with the user-defined DataSource connections
 *
 * @param string $name Connection name
 * @return void
 * @throws MissingDatasourceConfigException
 */
        protected static function _getConnectionObject($name) {
                if (!empty(static::$config->{$name})) {
                        static::$_connectionsEnum[$name] = static::_connectionData(static::$config->{$name});
                } else {
                        throw new MissingDatasourceConfigException(array('config' => $name));
                }
        }

/**
 * Returns the file, class name, and parent for the given driver.
 *
 * @param array $config Array with connection configuration. Key 'datasource' is required
 * @return array An indexed array with: filename, classname, plugin and parent
 */
        protected static function _connectionData($config) {
                $package = $classname = $plugin = null;

                list($plugin, $classname) = pluginSplit($config['datasource']);
                if (strpos($classname, '/') !== false) {
                        $package = dirname($classname);
                        $classname = basename($classname);
                }
                return compact('package', 'classname', 'plugin');
        }

}