lithium\storage\Session

class

The Session static class provides a consistent interface to configure and utilize the different persistent storage adapters included with Lithium, as well as your own adapters.

The Session layer of Lithium inherits from the common Adaptable class, which provides the generic configuration setting & retrieval logic, as well as the logic required to locate & instantiate the proper adapter class.

In most cases, you will configure various named session configurations in your bootstrap process, which will then be available to you in all other parts of your application.

Each adapter provides a consistent interface for the basic session operations like read, write, delete and check, which can be used interchangeably between all adapters.

For more information on Session methods and specific adapters, please see their relevant documentation.

Source

class Session extends \lithium\core\Adaptable {

	/**
	 * Stores configurations arrays for session adapters, keyed by configuration name.
	 *
	 * @var array
	 */
	protected static $_configurations = array();

	/**
	 * A dot-separated path for use by `Libraries::locate()`. Used to look up the correct type of
	 * adapters for this class.
	 *
	 * @var string
	 */
	protected static $_adapters = 'adapter.storage.session';

	/**
	 * `Libraries::locate()` compatible path to strategies for this class.
	 *
	 * @var string
	 */
	protected static $_strategies = 'strategy.storage.session';

	/**
	 * Returns (and Sets) the key used to identify the session.
	 *
	 * @param mixed $name Optional named session configuration.
	 * @param mixed $session_id Optional session id to use for this session.
	 * @return string Returns the value of the session identifier key, or `null` if no named
	 *         configuration exists, no session id has been set or no session has been started.
	 */
	public static function key($name = null, $sessionId = null) {
		return is_object($adapter = static::adapter($name)) ? $adapter->key($sessionId) : null;
	}

	/**
	 * Indicates whether the the current request includes information on a previously started
	 * session.
	 *
	 * @param string $name Optional named session configuration.
	 * @return boolean Returns `true` if a the request includes a key from a previously created
	 *         session.
	 */
	public static function isStarted($name = null) {
		return is_object($adapter = static::adapter($name)) ? $adapter->isStarted() : false;
	}

	/**
	 * Reads a value from a persistent session store.
	 *
	 * @param string $key Key to be read.
	 * @param array $options Optional parameters that this method accepts:
	 *              - `'name'` _string_: To force the read from a specific adapter, specify the name
	 *                of the configuration (i.e. `'default'`) here.
	 *              - `'strategies'` _boolean_: Indicates whether or not a configuration's applied
	 *                strategy classes should be enabled for this operation. Defaults to `true`.
	 * @return mixed Read result on successful session read, `null` otherwise.
	 * @filter
	 */
	public static function read($key = null, array $options = array()) {
		$defaults = array('name' => null, 'strategies' => true);
		$options += $defaults;
		$method = ($name = $options['name']) ? static::adapter($name)->read($key, $options) : null;
		$settings = static::_config($name);

		if (!$method) {
			foreach (array_keys(static::$_configurations) as $name) {
				if ($method = static::adapter($name)->read($key, $options)) {
					break;
				}
			}
			if (!$method || !$name) {
				return null;
			}
		}
		$filters = $settings['filters'] ?: array();
		$result = static::_filter(__FUNCTION__, compact('key', 'options'), $method, $filters);

		if ($options['strategies']) {
			$options += array('key' => $key, 'mode' => 'LIFO', 'class' => __CLASS__);
			return static::applyStrategies(__FUNCTION__, $name, $result, $options);
		}
		return $result;
	}

	/**
	 * Writes a persistent value to one or more session stores.
	 *
	 * @param string $key Key to be written.
	 * @param mixed $value Data to be stored.
	 * @param array $options Optional parameters that this method accepts:
	 *              - `'name'` _string_: To force the write to a specific adapter, specify the name
	 *                of the configuration (i.e. `'default'`) here.
	 *              - `'strategies'` _boolean_: Indicates whether or not a configuration's applied
	 *                strategy classes should be enabled for this operation. Defaults to `true`.
	 * @return boolean Returns `true` on successful write, `false` otherwise.
	 * @filter
	 */
	public static function write($key, $value = null, array $options = array()) {
		$defaults = array('name' => null, 'strategies' => true);
		$options += $defaults;

		if (is_resource($value) || !static::$_configurations) {
			return false;
		}
		$methods = array();

		if ($name = $options['name']) {
			$methods = array($name => static::adapter($name)->write($key, $value, $options));
		} else {
			foreach (array_keys(static::$_configurations) as $name) {
				if ($method = static::adapter($name)->write($key, $value, $options)) {
					$methods[$name] = $method;
				}
			}
		}
		$result = false;

		$original = $value;

		foreach ($methods as $name => $method) {
			$settings = static::_config($name);
			$filters = $settings['filters'];
			if ($options['strategies']) {
				$options += array('key' => $key, 'class' => __CLASS__);
				$value = static::applyStrategies(__FUNCTION__, $name, $original, $options);
			}
			$params = compact('key', 'value', 'options');
			$result = static::_filter(__FUNCTION__, $params, $method, $filters) || $result;
		}
		return $result;
	}

	/**
	 * Deletes a named key from a single adapter (if a `'name'` option is specified) or all
	 * session adapters.
	 *
	 * @param string $key The name of the session key to delete.
	 * @param array $options Optional parameters that this method accepts:
	 *              - `'name'` _string_: To force the delete to a specific adapter, specify the name
	 *                of the configuration (i.e. `'default'`) here.
	 *              - `'strategies'` _boolean_: Indicates whether or not a configuration's applied
	 *                strategy classes should be enabled for this operation. Defaults to `true`.
	 * @return boolean Returns `true` on successful delete, or `false` on failure.
	 * @filter
	 */
	public static function delete($key, array $options = array()) {
		$defaults = array('name' => null, 'strategies' => true);
		$options += $defaults;

		$methods = array();

		if ($name = $options['name']) {
			$methods = array($name => static::adapter($name)->delete($key, $options));
		} else {
			foreach (static::$_configurations as $name => $config) {
				if ($method = static::adapter($name)->delete($key, $options)) {
					$methods[$name] = $method;
				}
			}
		}
		$result = false;
		$options += array('key' => $key, 'class' => __CLASS__);
		$original = $key;

		foreach ($methods as $name => $method) {
			$settings = static::_config($name);
			if ($options['strategies']) {
				$options += array('key' => $key, 'class' => __CLASS__);
				$key = static::applyStrategies(__FUNCTION__, $name, $original, $options);
			}
			$params = compact('key', 'options');
			$filters = $settings['filters'];
			$result = static::_filter(__FUNCTION__, $params, $method, $filters) || $result;
		}
		return $result;
	}

	/**
	 * Clears all keys from a single adapter (if a `'name'` options is specified) or all
	 * session adapters.
	 *
	 * @param array $options Optional parameters that this method accepts:
	 *              - `'name'` _string_: To force the write to a specific adapter, specify the name
	 *                of the configuration (i.e. `'default'`) here.
	 *              - `'strategies'` _boolean_: Indicates whether or not a configuration's applied
	 *                strategy classes should be enabled for this operation. Defaults to `true`.
	 * @filter
	 */
	public static function clear(array $options = array()) {
		$defaults = array('name' => null, 'strategies' => true);
		$options += $defaults;
		$methods = array();

		if ($name = $options['name']) {
			$methods = array($name => static::adapter($name)->clear($options));
		} else {
			foreach (static::$_configurations as $name => $config) {
				if ($method = static::adapter($name)->clear($options)) {
					$methods[$name] = $method;
				}
			}
		}
		$params = compact('options');
		$result = false;

		foreach ($methods as $name => $method) {
			$settings = static::_config($name);
			$filters = $settings['filters'];
			$result = static::_filter(__FUNCTION__, $params, $method, $filters) || $result;
		}
		if ($options['strategies']) {
			$options += array('mode' => 'LIFO', 'class' => __CLASS__);
			return static::applyStrategies(__FUNCTION__, $name, $result, $options);
		}
		return $result;
	}

	/**
	 * Checks if a session key is set in any adapter, or if a particular adapter configuration is
	 * specified (via `'name'` in `$options`), only that configuration is checked.
	 *
	 * @param string $key The session key to check.
	 * @param array $options Optional parameters that this method accepts.
	 * @return boolean
	 * @filter
	 */
	public static function check($key, array $options = array()) {
		$defaults = array('name' => null, 'strategies' => true);
		$options += $defaults;
		$methods = array();

		if ($name = $options['name']) {
			$methods = array($name => static::adapter($name)->check($key, $options));
		} else {
			foreach (static::$_configurations as $name => $config) {
				if ($method = static::adapter($name)->check($key, $options)) {
					$methods[$name] = $method;
				}
			}
		}
		$params = compact('key', 'options');
		$result = false;

		foreach ($methods as $name => $method) {
			$settings = static::_config($name);
			$filters = $settings['filters'];
			$result = static::_filter(__FUNCTION__, $params, $method, $filters) || $result;
		}
		if ($options['strategies']) {
			$options += array('key' => $key, 'mode' => 'LIFO', 'class' => __CLASS__);
			return static::applyStrategies(__FUNCTION__, $name, $result, $options);
		}
		return $result;
	}

	/**
	 * Returns the adapter object instance of the named configuration.
	 *
	 * @param string $name Named configuration. If not set, the last configured
	 *        adapter object instance will be returned.
	 * @return object Adapter instance.
	 */
	public static function adapter($name = null) {
		if (!$name) {
			if (!$names = array_keys(static::$_configurations)) {
				return;
			}
			$name = end($names);
		}
		return parent::adapter($name);
	}
}