<?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.
 *
 * @package log4php
 */

/**
 * Returns a value from a superglobal array corresponding to the 
 * given key.
 * 
 * Option: the key to look up within the superglobal array
 * 
 * Also, it is possible that a superglobal variable is not populated by PHP
 * because of the settings in the variables-order ini directive. In this case
 * the converter will return an empty value.
 * 
 * @see http://php.net/manual/en/language.variables.superglobals.php
 * @see http://www.php.net/manual/en/ini.core.php#ini.variables-order
 * 
 * @package log4php
 * @subpackage pattern
 * @since 2.3
 */
abstract class LoggerPatternConverterSuperglobal extends LoggerPatternConverter {
	
	protected $value = '';
	
	public function activateOptions() {
		// Read the key from options array
		if (isset($this->option) && $this->option !== '') {
			$key = $this->option;
		}

		$source = $this->getSource();
		
		// When the key is set, display the matching value
		if (isset($key)) {
			if (isset($source[$key])) {
				$this->value = $source[$key]; 
			}
		}
		
		// When the key is not set, display all values
		else {
			$values = array();
			foreach($source as $key => $value) {
				$values[] = "$key=$value";
			}
			$this->value = implode(', ', $values);			
		}
	}
	
	public function convert(LoggerLoggingEvent $event) {
		return $this->value;
	}
}