src/Configuration/DefaultConfigurator.php - logging-log4php - Git at Google

 <?php
 /**
  * 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.
  */

 namespace Apache\Log4php\Configuration;

 use Apache\Log4php\Appenders\AbstractAppender;
 use Apache\Log4php\Filters\AbstractFilter;
 use Apache\Log4php\Helpers\OptionConverter;
 use Apache\Log4php\Hierarchy;
 use Apache\Log4php\Layouts\AbstractLayout;
 use Apache\Log4php\Level;
 use Apache\Log4php\Logger;
 use Apache\Log4php\LoggerException;

 /**
  * Default implementation of the logger configurator.
  *
  * Configures log4php based on a provided configuration file or array.
  * @license http://www.apache.org/licenses/LICENSE-2.0 Apache License, Version 2.0
  * @since 2.2
  */
 class DefaultConfigurator implements ConfiguratorInterface
 {
     /** XML configuration file format. */
     const FORMAT_XML = 'xml';

     /** PHP configuration file format. */
     const FORMAT_PHP = 'php';

     /** INI (properties) configuration file format. */
     const FORMAT_INI = 'ini';

     /** Defines which adapter should be used for parsing which format. */
     private $adapters = array(
         self::FORMAT_XML => 'XmlAdapter',
         self::FORMAT_INI => 'IniAdapter',
         self::FORMAT_PHP => 'PhpAdapter',
     );

     /** Default configuration; used if no configuration file is provided. */
     private static $defaultConfiguration = array(
         'threshold' => 'ALL',
         'rootLogger' => array(
             'level' => 'DEBUG',
             'appenders' => array('default'),
         ),
         'appenders' => array(
             'default' => array(
                 'class' => '\\Apache\\Log4php\\Appenders\\EchoAppender'
             ),
         ),
     );

     /** Holds the appenders before they are linked to loggers. */
     private $appenders = array();

     /**
      * Configures log4php based on the given configuration. The input can either
      * be a path to the config file, or a PHP array holding the configuration.
      *
      * If no configuration is given, or if the given configuration cannot be
      * parsed for whatever reason, a warning will be issued, and log4php will
      * use the default configuration contained in {@link $defaultConfiguration}.
      *
      * @param Hierarchy $hierarchy The hierarchy on which to perform the
      * configuration.
      *
      * @param string|array $input Either path to the config file or the
      * configuration as an array. If not set, default configuration will be
      * used.
      */
     public function configure(Hierarchy $hierarchy, $input = null)
     {
         $config = $this->parse($input);
         $this->doConfigure($hierarchy, $config);
     }

     /**
      * Parses the given configuration and returns the parsed configuration as a
      * PHP array. Does not perform any configuration.
      *
      * If no configuration is given, or if the given configuration cannot be
      * parsed for whatever reason, a warning will be issued, and the default
      * configuration will be returned ({@link $defaultConfiguration}).
      *
      * @param string|array $input Either path to the config file or the
      * configuration as an array. If not set, default configuration will be
      * used.
      *
      * @return array The parsed configuration.
      */
     public function parse($input)
     {
         if (!isset($input)) {
             // No input - use default configuration
             $config = self::$defaultConfiguration;
         } elseif (is_array($input)) {
             // Array input - contains configuration within the array
             $config = $input;
         } elseif (is_string($input)) {
             // String input - contains path to configuration file
             try {
                 $config = $this->parseFile($input);
             } catch (LoggerException $e) {
                 $this->warn("Configuration failed. " . $e->getMessage() . " Using default configuration.");
                 $config = self::$defaultConfiguration;
             }
         } else {
             // Anything else is an error
             $this->warn("Invalid configuration param given. Reverting to default configuration.");
             $config = self::$defaultConfiguration;
         }

         return $config;
     }

     /**
      * Returns the default log4php configuration.
      * @return array
      */
     public static function getDefaultConfiguration()
     {
         return self::$defaultConfiguration;
     }

     /**
      * Loads the configuration file from the given URL, determines which
      * adapter to use, converts the configuration to a PHP array and
      * returns it.
      *
      * @param  string $url Path to the config file.
      * @return The configuration from the config file, as a PHP array.
      * @throws LoggerException If the configuration file cannot be loaded, or
      * if the parsing fails.
      */
     private function parseFile($url)
     {
         if (!file_exists($url)) {
             throw new LoggerException("File not found at [$url].");
         }

         $type = $this->getConfigType($url);
         $adapterClass = "Apache\\Log4php\\Configuration\\Adapters\\" . $this->adapters[$type];

         $adapter = new $adapterClass();

         return $adapter->convert($url);
     }

     /** Determines configuration file type based on the file extension. */
     private function getConfigType($url)
     {
         $info = pathinfo($url);
         $ext = strtolower($info['extension']);

         switch ($ext) {
             case 'xml':
                 return self::FORMAT_XML;

             case 'ini':
             case 'properties':
                 return self::FORMAT_INI;

             case 'php':
                 return self::FORMAT_PHP;

             default:
                 throw new LoggerException("Unsupported configuration file extension: $ext");
         }
     }

     /**
      * Constructs the logger hierarchy based on configuration.
      *
      * @param Hierarchy $hierarchy
      * @param array     $config
      */
     private function doConfigure(Hierarchy $hierarchy, $config)
     {
         if (isset($config['threshold'])) {
             $threshold = Level::toLevel($config['threshold']);
             if (isset($threshold)) {
                 $hierarchy->setThreshold($threshold);
             } else {
                 $this->warn(
                     "Invalid threshold value [{$config['threshold']}] specified. " .
                     "Ignoring threshold definition."
                 );
             }
         }

         // Configure appenders and add them to the appender pool
         if (isset($config['appenders']) && is_array($config['appenders'])) {
             foreach ($config['appenders'] as $name => $appenderConfig) {
                 $this->configureAppender($name, $appenderConfig);
             }
         }

         // Configure root logger
         if (isset($config['rootLogger'])) {
             $this->configureRootLogger($hierarchy, $config['rootLogger']);
         }

         // Configure loggers
         if (isset($config['loggers']) && is_array($config['loggers'])) {
             foreach ($config['loggers'] as $loggerName => $loggerConfig) {
                 $this->configureOtherLogger($hierarchy, $loggerName, $loggerConfig);
             }
         }

         // Configure renderers
         if (isset($config['renderers']) && is_array($config['renderers'])) {
             foreach ($config['renderers'] as $rendererConfig) {
                 $this->configureRenderer($hierarchy, $rendererConfig);
             }
         }

         if (isset($config['defaultRenderer'])) {
             $this->configureDefaultRenderer($hierarchy, $config['defaultRenderer']);
         }
     }

     private function configureRenderer(Hierarchy $hierarchy, $config)
     {
         if (empty($config['renderingClass'])) {
             $this->warn("Rendering class not specified. Skipping renderer definition.");

             return;
         }

         if (empty($config['renderedClass'])) {
             $this->warn("Rendered class not specified. Skipping renderer definition.");

             return;
         }

         // Error handling performed by RendererMap
         $hierarchy->getRendererMap()->addRenderer($config['renderedClass'], $config['renderingClass']);
     }

     private function configureDefaultRenderer(Hierarchy $hierarchy, $class)
     {
         if (empty($class)) {
             $this->warn("Rendering class not specified. Skipping default renderer definition.");

             return;
         }

         // Error handling performed by RendererMap
         $hierarchy->getRendererMap()->setDefaultRenderer($class);
     }

     /**
      * Configures an appender based on given config and saves it to
      * {@link $appenders} array so it can be later linked to loggers.
      * @param string $name   Appender name.
      * @param array  $config Appender configuration options.
      */
     private function configureAppender($name, $config)
     {
         // TODO: add this check to other places where it might be useful
         if (!is_array($config)) {
             $type = gettype($config);
             $this->warn(
                 "Invalid configuration provided for appender [$name]. Expected an array, found <$type>. " .
                 "Skipping appender definition."
             );

             return;
         }

         // Parse appender class
         $class = $config['class'];
         if (empty($class)) {
             $this->warn("No class given for appender [$name]. Skipping appender definition.");

             return;
         }

         // Instantiate the appender
         if (class_exists($class)) {
             $appender = new $class($name);
         } else {
             // Try the default namespace
             $nsClass = "\\Apache\\Log4php\\Appenders\\$class";
             if (class_exists($nsClass)) {
                 $appender = new $nsClass($name);
             }
         }

         if (!isset($appender)) {
             $this->warn(
                 "Invalid class [$class] given for appender [$name]. Class does not exist. " .
                 "Skipping appender definition."
             );

             return;
         }

         if (!($appender instanceof AbstractAppender)) {
             $this->warn(
                 "Invalid class [$class] given for appender [$name]. Not a valid Appender class. " .
                 "Skipping appender definition."
             );

             return;
         }

         // Parse the appender threshold
         if (isset($config['threshold'])) {
             $threshold = Level::toLevel($config['threshold']);
             if ($threshold instanceof Level) {
                 $appender->setThreshold($threshold);
             } else {
                 $this->warn(
                     "Invalid threshold value [{$config['threshold']}] specified for appender [$name]. " .
                     "Ignoring threshold definition."
                 );
             }
         }

         // Parse the appender layout
         if ($appender->requiresLayout() && isset($config['layout'])) {
             $this->createAppenderLayout($appender, $config['layout']);
         }

         // Parse filters
         if (isset($config['filters']) && is_array($config['filters'])) {
             foreach ($config['filters'] as $filterConfig) {
                 $this->createAppenderFilter($appender, $filterConfig);
             }
         }

         // Set options if any
         if (isset($config['params'])) {
             $this->setOptions($appender, $config['params']);
         }

         // Activate and save for later linking to loggers
         $appender->activateOptions();
         $this->appenders[$name] = $appender;
     }

     /**
      * Parses layout config, creates the layout and links it to the appender.
      * @param AbstractAppender $appender
      * @param array            $config   Layout configuration.
      */
     private function createAppenderLayout(AbstractAppender $appender, $config)
     {
         $name = $appender->getName();
         $class = $config['class'];
         if (empty($class)) {
             $this->warn("Layout class not specified for appender [$name]. Reverting to default layout.");

             return;
         }

         if (class_exists($class)) {
             $layout = new $class();
         } else {
             $nsClass = "Apache\\Log4php\\Layouts\\$class";
             if (class_exists($nsClass)) {
                 $layout = new $nsClass();
             }
         }

         if (!isset($layout)) {
             $this->warn(
                 "Nonexistant layout class [$class] specified for appender [$name]. " .
                 "Reverting to default layout."
             );

             return;
         }

         if (!($layout instanceof AbstractLayout)) {
             $this->warn("Invalid layout class [$class] sepcified for appender [$name]. Reverting to default layout.");

             return;
         }

         if (isset($config['params'])) {
             $this->setOptions($layout, $config['params']);
         }

         $layout->activateOptions();
         $appender->setLayout($layout);
     }

     /**
      * Parses filter config, creates the filter and adds it to the appender's
      * filter chain.
      * @param Appender $appender
      * @param array    $config   Filter configuration.
      */
     private function createAppenderFilter(AbstractAppender $appender, $config)
     {
         $name = $appender->getName();
         $class = $config['class'];

         if (class_exists($class)) {
             $filter = new $class();
         } else {
             $nsClass = "Apache\\Log4php\\Filters\\$class";
             if (class_exists($nsClass)) {
                 $filter = new $nsClass();
             }
         }

         if (!isset($filter)) {
             $this->warn("Nonexistant filter class [$class] specified on appender [$name]. Skipping filter definition.");

             return;
         }

         if (!($filter instanceof AbstractFilter)) {
             $this->warn("Invalid filter class [$class] sepcified on appender [$name]. Skipping filter definition.");

             return;
         }

         if (isset($config['params'])) {
             $this->setOptions($filter, $config['params']);
         }

         $filter->activateOptions();
         $appender->addFilter($filter);
     }

     /**
      * Configures the root logger
      * @see configureLogger()
      */
     private function configureRootLogger(Hierarchy $hierarchy, $config)
     {
         $logger = $hierarchy->getRootLogger();
         $this->configureLogger($logger, $config);
     }

     /**
      * Configures a logger which is not root.
      * @see configureLogger()
      */
     private function configureOtherLogger(Hierarchy $hierarchy, $name, $config)
     {
         // Get logger from hierarchy (this creates it if it doesn't already exist)
         $logger = $hierarchy->getLogger($name);
         $this->configureLogger($logger, $config);
     }

     /**
      * Configures a logger.
      *
      * @param Logger $logger The logger to configure
      * @param array  $config Logger configuration options.
      */
     private function configureLogger(Logger $logger, $config)
     {
         $loggerName = $logger->getName();

         // Set logger level
         if (isset($config['level'])) {
             $level = Level::toLevel($config['level']);
             if (isset($level)) {
                 $logger->setLevel($level);
             } else {
                 $this->warn(
                     "Invalid level value [{$config['level']}] specified for logger [$loggerName]. " .
                     "Ignoring level definition."
                 );
             }
         }

         // Link appenders to logger
         if (isset($config['appenders'])) {
             foreach ($config['appenders'] as $appenderName) {
                 if (isset($this->appenders[$appenderName])) {
                     $logger->addAppender($this->appenders[$appenderName]);
                 } else {
                     $this->warn("Nonexistnant appender [$appenderName] linked to logger [$loggerName].");
                 }
             }
         }

         // Set logger additivity
         if (isset($config['additivity'])) {
             try {
                 $additivity = OptionConverter::toBooleanEx($config['additivity'], null);
                 $logger->setAdditivity($additivity);
             } catch (LoggerException $ex) {
                 $this->warn(
                     "Invalid additivity value [{$config['additivity']}] specified for logger [$loggerName]. " .
                     "Ignoring additivity setting."
                 );
             }
         }
     }

     /**
      * Helper method which applies given options to an object which has setters
      * for these options (such as appenders, layouts, etc.).
      *
      * For example, if options are:
      * <code>
      * array(
      *   'file' => '/tmp/myfile.log',
      *   'append' => true
      * )
      * </code>
      *
      * This method will call:
      * <code>
      * $object->setFile('/tmp/myfile.log')
      * $object->setAppend(true)
      * </code>
      *
      * If required setters do not exist, it will produce a warning.
      *
      * @param mixed $object  The object to configure.
      * @param array $options
      */
     private function setOptions($object, $options)
     {
         foreach ($options as $name => $value) {
             $setter = "set$name";
             if (method_exists($object, $setter)) {
                 $object->$setter($value);
             } else {
                 $class = get_class($object);
                 $this->warn("Nonexistant option [$name] specified on [$class]. Skipping.");
             }
         }
     }

     /** Helper method to simplify error reporting. */
     private function warn($message)
     {
         trigger_error("log4php: $message", E_USER_WARNING);
     }
 }
	<?php
	/**
	* 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.
	*/

	namespace Apache\Log4php\Configuration;

	use Apache\Log4php\Appenders\AbstractAppender;
	use Apache\Log4php\Filters\AbstractFilter;
	use Apache\Log4php\Helpers\OptionConverter;
	use Apache\Log4php\Hierarchy;
	use Apache\Log4php\Layouts\AbstractLayout;
	use Apache\Log4php\Level;
	use Apache\Log4php\Logger;
	use Apache\Log4php\LoggerException;

	/**
	* Default implementation of the logger configurator.
	*
	* Configures log4php based on a provided configuration file or array.
	* @license http://www.apache.org/licenses/LICENSE-2.0 Apache License, Version 2.0
	* @since 2.2
	*/
	class DefaultConfigurator implements ConfiguratorInterface
	{
	/** XML configuration file format. */
	const FORMAT_XML = 'xml';

	/** PHP configuration file format. */
	const FORMAT_PHP = 'php';

	/** INI (properties) configuration file format. */
	const FORMAT_INI = 'ini';

	/** Defines which adapter should be used for parsing which format. */
	private $adapters = array(
	self::FORMAT_XML => 'XmlAdapter',
	self::FORMAT_INI => 'IniAdapter',
	self::FORMAT_PHP => 'PhpAdapter',
	);

	/** Default configuration; used if no configuration file is provided. */
	private static $defaultConfiguration = array(
	'threshold' => 'ALL',
	'rootLogger' => array(
	'level' => 'DEBUG',
	'appenders' => array('default'),
	),
	'appenders' => array(
	'default' => array(
	'class' => '\\Apache\\Log4php\\Appenders\\EchoAppender'
	),
	),
	);

	/** Holds the appenders before they are linked to loggers. */
	private $appenders = array();

	/**
	* Configures log4php based on the given configuration. The input can either
	* be a path to the config file, or a PHP array holding the configuration.
	*
	* If no configuration is given, or if the given configuration cannot be
	* parsed for whatever reason, a warning will be issued, and log4php will
	* use the default configuration contained in {@link $defaultConfiguration}.
	*
	* @param Hierarchy $hierarchy The hierarchy on which to perform the
	* configuration.
	*
	* @param string\|array $input Either path to the config file or the
	* configuration as an array. If not set, default configuration will be
	* used.
	*/
	public function configure(Hierarchy $hierarchy, $input = null)
	{
	$config = $this->parse($input);
	$this->doConfigure($hierarchy, $config);
	}

	/**
	* Parses the given configuration and returns the parsed configuration as a
	* PHP array. Does not perform any configuration.
	*
	* If no configuration is given, or if the given configuration cannot be
	* parsed for whatever reason, a warning will be issued, and the default
	* configuration will be returned ({@link $defaultConfiguration}).
	*
	* @param string\|array $input Either path to the config file or the
	* configuration as an array. If not set, default configuration will be
	* used.
	*
	* @return array The parsed configuration.
	*/
	public function parse($input)
	{
	if (!isset($input)) {
	// No input - use default configuration
	$config = self::$defaultConfiguration;
	} elseif (is_array($input)) {
	// Array input - contains configuration within the array
	$config = $input;
	} elseif (is_string($input)) {
	// String input - contains path to configuration file
	try {
	$config = $this->parseFile($input);
	} catch (LoggerException $e) {
	$this->warn("Configuration failed. " . $e->getMessage() . " Using default configuration.");
	$config = self::$defaultConfiguration;
	}
	} else {
	// Anything else is an error
	$this->warn("Invalid configuration param given. Reverting to default configuration.");
	$config = self::$defaultConfiguration;
	}

	return $config;
	}

	/**
	* Returns the default log4php configuration.
	* @return array
	*/
	public static function getDefaultConfiguration()
	{
	return self::$defaultConfiguration;
	}

	/**
	* Loads the configuration file from the given URL, determines which
	* adapter to use, converts the configuration to a PHP array and
	* returns it.
	*
	* @param string $url Path to the config file.
	* @return The configuration from the config file, as a PHP array.
	* @throws LoggerException If the configuration file cannot be loaded, or
	* if the parsing fails.
	*/
	private function parseFile($url)
	{
	if (!file_exists($url)) {
	throw new LoggerException("File not found at [$url].");
	}

	$type = $this->getConfigType($url);
	$adapterClass = "Apache\\Log4php\\Configuration\\Adapters\\" . $this->adapters[$type];

	$adapter = new $adapterClass();

	return $adapter->convert($url);
	}

	/** Determines configuration file type based on the file extension. */
	private function getConfigType($url)
	{
	$info = pathinfo($url);
	$ext = strtolower($info['extension']);

	switch ($ext) {
	case 'xml':
	return self::FORMAT_XML;

	case 'ini':
	case 'properties':
	return self::FORMAT_INI;

	case 'php':
	return self::FORMAT_PHP;

	default:
	throw new LoggerException("Unsupported configuration file extension: $ext");
	}
	}

	/**
	* Constructs the logger hierarchy based on configuration.
	*
	* @param Hierarchy $hierarchy
	* @param array $config
	*/
	private function doConfigure(Hierarchy $hierarchy, $config)
	{
	if (isset($config['threshold'])) {
	$threshold = Level::toLevel($config['threshold']);
	if (isset($threshold)) {
	$hierarchy->setThreshold($threshold);
	} else {
	$this->warn(
	"Invalid threshold value [{$config['threshold']}] specified. " .
	"Ignoring threshold definition."
	);
	}
	}

	// Configure appenders and add them to the appender pool
	if (isset($config['appenders']) && is_array($config['appenders'])) {
	foreach ($config['appenders'] as $name => $appenderConfig) {
	$this->configureAppender($name, $appenderConfig);
	}
	}

	// Configure root logger
	if (isset($config['rootLogger'])) {
	$this->configureRootLogger($hierarchy, $config['rootLogger']);
	}

	// Configure loggers
	if (isset($config['loggers']) && is_array($config['loggers'])) {
	foreach ($config['loggers'] as $loggerName => $loggerConfig) {
	$this->configureOtherLogger($hierarchy, $loggerName, $loggerConfig);
	}
	}

	// Configure renderers
	if (isset($config['renderers']) && is_array($config['renderers'])) {
	foreach ($config['renderers'] as $rendererConfig) {
	$this->configureRenderer($hierarchy, $rendererConfig);
	}
	}

	if (isset($config['defaultRenderer'])) {
	$this->configureDefaultRenderer($hierarchy, $config['defaultRenderer']);
	}
	}

	private function configureRenderer(Hierarchy $hierarchy, $config)
	{
	if (empty($config['renderingClass'])) {
	$this->warn("Rendering class not specified. Skipping renderer definition.");

	return;
	}

	if (empty($config['renderedClass'])) {
	$this->warn("Rendered class not specified. Skipping renderer definition.");

	return;
	}

	// Error handling performed by RendererMap
	$hierarchy->getRendererMap()->addRenderer($config['renderedClass'], $config['renderingClass']);
	}

	private function configureDefaultRenderer(Hierarchy $hierarchy, $class)
	{
	if (empty($class)) {
	$this->warn("Rendering class not specified. Skipping default renderer definition.");

	return;
	}

	// Error handling performed by RendererMap
	$hierarchy->getRendererMap()->setDefaultRenderer($class);
	}

	/**
	* Configures an appender based on given config and saves it to
	* {@link $appenders} array so it can be later linked to loggers.
	* @param string $name Appender name.
	* @param array $config Appender configuration options.
	*/
	private function configureAppender($name, $config)
	{
	// TODO: add this check to other places where it might be useful
	if (!is_array($config)) {
	$type = gettype($config);
	$this->warn(
	"Invalid configuration provided for appender [$name]. Expected an array, found <$type>. " .
	"Skipping appender definition."
	);

	return;
	}

	// Parse appender class
	$class = $config['class'];
	if (empty($class)) {
	$this->warn("No class given for appender [$name]. Skipping appender definition.");

	return;
	}

	// Instantiate the appender
	if (class_exists($class)) {
	$appender = new $class($name);
	} else {
	// Try the default namespace
	$nsClass = "\\Apache\\Log4php\\Appenders\\$class";
	if (class_exists($nsClass)) {
	$appender = new $nsClass($name);
	}
	}

	if (!isset($appender)) {
	$this->warn(
	"Invalid class [$class] given for appender [$name]. Class does not exist. " .
	"Skipping appender definition."
	);

	return;
	}

	if (!($appender instanceof AbstractAppender)) {
	$this->warn(
	"Invalid class [$class] given for appender [$name]. Not a valid Appender class. " .
	"Skipping appender definition."
	);

	return;
	}

	// Parse the appender threshold
	if (isset($config['threshold'])) {
	$threshold = Level::toLevel($config['threshold']);
	if ($threshold instanceof Level) {
	$appender->setThreshold($threshold);
	} else {
	$this->warn(
	"Invalid threshold value [{$config['threshold']}] specified for appender [$name]. " .
	"Ignoring threshold definition."
	);
	}
	}

	// Parse the appender layout
	if ($appender->requiresLayout() && isset($config['layout'])) {
	$this->createAppenderLayout($appender, $config['layout']);
	}

	// Parse filters
	if (isset($config['filters']) && is_array($config['filters'])) {
	foreach ($config['filters'] as $filterConfig) {
	$this->createAppenderFilter($appender, $filterConfig);
	}
	}

	// Set options if any
	if (isset($config['params'])) {
	$this->setOptions($appender, $config['params']);
	}

	// Activate and save for later linking to loggers
	$appender->activateOptions();
	$this->appenders[$name] = $appender;
	}

	/**
	* Parses layout config, creates the layout and links it to the appender.
	* @param AbstractAppender $appender
	* @param array $config Layout configuration.
	*/
	private function createAppenderLayout(AbstractAppender $appender, $config)
	{
	$name = $appender->getName();
	$class = $config['class'];
	if (empty($class)) {
	$this->warn("Layout class not specified for appender [$name]. Reverting to default layout.");

	return;
	}

	if (class_exists($class)) {
	$layout = new $class();
	} else {
	$nsClass = "Apache\\Log4php\\Layouts\\$class";
	if (class_exists($nsClass)) {
	$layout = new $nsClass();
	}
	}

	if (!isset($layout)) {
	$this->warn(
	"Nonexistant layout class [$class] specified for appender [$name]. " .
	"Reverting to default layout."
	);

	return;
	}

	if (!($layout instanceof AbstractLayout)) {
	$this->warn("Invalid layout class [$class] sepcified for appender [$name]. Reverting to default layout.");

	return;
	}

	if (isset($config['params'])) {
	$this->setOptions($layout, $config['params']);
	}

	$layout->activateOptions();
	$appender->setLayout($layout);
	}

	/**
	* Parses filter config, creates the filter and adds it to the appender's
	* filter chain.
	* @param Appender $appender
	* @param array $config Filter configuration.
	*/
	private function createAppenderFilter(AbstractAppender $appender, $config)
	{
	$name = $appender->getName();
	$class = $config['class'];

	if (class_exists($class)) {
	$filter = new $class();
	} else {
	$nsClass = "Apache\\Log4php\\Filters\\$class";
	if (class_exists($nsClass)) {
	$filter = new $nsClass();
	}
	}

	if (!isset($filter)) {
	$this->warn("Nonexistant filter class [$class] specified on appender [$name]. Skipping filter definition.");

	return;
	}

	if (!($filter instanceof AbstractFilter)) {
	$this->warn("Invalid filter class [$class] sepcified on appender [$name]. Skipping filter definition.");

	return;
	}

	if (isset($config['params'])) {
	$this->setOptions($filter, $config['params']);
	}

	$filter->activateOptions();
	$appender->addFilter($filter);
	}

	/**
	* Configures the root logger
	* @see configureLogger()
	*/
	private function configureRootLogger(Hierarchy $hierarchy, $config)
	{
	$logger = $hierarchy->getRootLogger();
	$this->configureLogger($logger, $config);
	}

	/**
	* Configures a logger which is not root.
	* @see configureLogger()
	*/
	private function configureOtherLogger(Hierarchy $hierarchy, $name, $config)
	{
	// Get logger from hierarchy (this creates it if it doesn't already exist)
	$logger = $hierarchy->getLogger($name);
	$this->configureLogger($logger, $config);
	}

	/**
	* Configures a logger.
	*
	* @param Logger $logger The logger to configure
	* @param array $config Logger configuration options.
	*/
	private function configureLogger(Logger $logger, $config)
	{
	$loggerName = $logger->getName();

	// Set logger level
	if (isset($config['level'])) {
	$level = Level::toLevel($config['level']);
	if (isset($level)) {
	$logger->setLevel($level);
	} else {
	$this->warn(
	"Invalid level value [{$config['level']}] specified for logger [$loggerName]. " .
	"Ignoring level definition."
	);
	}
	}

	// Link appenders to logger
	if (isset($config['appenders'])) {
	foreach ($config['appenders'] as $appenderName) {
	if (isset($this->appenders[$appenderName])) {
	$logger->addAppender($this->appenders[$appenderName]);
	} else {
	$this->warn("Nonexistnant appender [$appenderName] linked to logger [$loggerName].");
	}
	}
	}

	// Set logger additivity
	if (isset($config['additivity'])) {
	try {
	$additivity = OptionConverter::toBooleanEx($config['additivity'], null);
	$logger->setAdditivity($additivity);
	} catch (LoggerException $ex) {
	$this->warn(
	"Invalid additivity value [{$config['additivity']}] specified for logger [$loggerName]. " .
	"Ignoring additivity setting."
	);
	}
	}
	}

	/**
	* Helper method which applies given options to an object which has setters
	* for these options (such as appenders, layouts, etc.).
	*
	* For example, if options are:
	* <code>
	* array(
	* 'file' => '/tmp/myfile.log',
	* 'append' => true
	* )
	* </code>
	*
	* This method will call:
	* <code>
	* $object->setFile('/tmp/myfile.log')
	* $object->setAppend(true)
	* </code>
	*
	* If required setters do not exist, it will produce a warning.
	*
	* @param mixed $object The object to configure.
	* @param array $options
	*/
	private function setOptions($object, $options)
	{
	foreach ($options as $name => $value) {
	$setter = "set$name";
	if (method_exists($object, $setter)) {
	$object->$setter($value);
	} else {
	$class = get_class($object);
	$this->warn("Nonexistant option [$name] specified on [$class]. Skipping.");
	}
	}
	}

	/** Helper method to simplify error reporting. */
	private function warn($message)
	{
	trigger_error("log4php: $message", E_USER_WARNING);
	}
	}