[Stack-cvs] stack-dev/lib Logger.php,NONE,1.1

[Jonathan H. <j_...@us...>]

Update of /cvsroot/stack/stack-dev/lib
In directory sc8-pr-cvs8.sourceforge.net:/tmp/cvs-serv15921/lib

Added Files:
	Logger.php 
Log Message:
Initial commit of logging framework

--- NEW FILE: Logger.php ---
<?php
/**
*
* Welcome to STACK.  A system for teaching and assessment using a
* computer algebra kernel.
* <br />
* This file is licensed under the GPL License.
* <br />
* A copy of the license is in your STACK distribution called
* license.txt.  If you are missing this file you can obtain
* it from:
* http://www.stack.bham.ac.uk/license.txt
* <br />
*
* @author Jonathan Hart (jh...@gm...)
*
* @package stackUtil
*/
/**
*Logging class for debug messages. 
*Writes to messages to the $log dir under debug.log
*For error logging use the error class.
*
*Heavily based on Java logging levels and log4j.
*/

global $config;
$root = $config->get('docroot');
require_once $root.'/lib/dateTime.php';

class Logger{
	
	/**
	 * 
	 */
	private $className;
	
	/**
	 * The filename logs will be appended to (in the $log directory)
	 * 
	 * @access private
	 * @var $filename
	 */
	private $filename = "stack.log";
	
	/**
	 * The current debug level set in the config.php file.
	 * 
	 */
	private $currentLevel;
	
	/**
	 * Debug levels
	 * 
	 */
	private $debugLevel;
	
	/**
	 * Constucts a new logger
	 * 
	 * @access public
	 * @param $classname String The name of the class / function the logger is called on.
	 */
	public function __construct($className){
		$this->className = $className;
		
		global $config;
		switch (strtolower($config->get('debug'))){
			case 'false': $this->currentLevel = 0;
				break;
				case 'false': $this->currentLevel = 0;
				break;
				case 'critical': $this->currentLevel = 10;
				break;
				case 'error': $this->currentLevel = 20;
				break;
				case 'warn': $this->currentLevel = 30;
				break;
				case 'info': $this->currentLevel = 40;
				break;
				case 'debug': $this->currentLevel = 50;
				break;
				case 'fine': $this->currentLevel = 60;
				break;
				case 'finer': $this->currentLevel = 70;
				break;
				case 'finest': $this->currentLevel = 80;
				break;
				default: $this->currentLevel = 0;
				
		}
		
		$this->debugLevel['off'] = 0;
		$this->debugLevel['critical'] = 10;
		$this->debugLevel['error'] = 20;
		$this->debugLevel['warn'] = 30;
		$this->debugLevel['info'] = 40;
		$this->debugLevel['debug'] = 50;
		$this->debugLevel['fine'] = 60;
		$this->debugLevel['finer'] = 70;
		$this->debugLevel['finest'] = 80;
	}
	
	/**
	 * Logs an info message
	 * 
	 * @access public 
	 * @param $msg String|Boolean
	 */
	public function info($msg){
		if($this->currentLevel >= $this->debugLevel['info']){
			$this->writeOut("INFO",$msg);
		}
	}
	
	/**
	 * Logs a debug message
	 * 
	 * @access public
	 * @param $msg String|Boolean
	 */
	public function debug($msg){
		if($this->currentLevel >= $this->debugLevel['debug']){
			$this->writeOut("DEBUG",$msg);
		}
	}
	
	/**
	 * Logs a fine gained debug message
	 * 
	 * @access public
	 * @param $msg String|Boolean
	 */
	public function fine($msg){
		if($this->currentLevel >= $this->debugLevel['fine']){
			$this->writeOut("FINE",$msg);
		}
	}
	
	/**
	 * Logs a finer gained debug message
	 * 
	 * @access public
	 * @param $msg String|Boolean
	 */
	public function finer($msg){
		if($this->currentLevel >= $this->debugLevel['finer']){
			$this->writeOut("FINER",$msg);
		}
	}
	
	/**
	 * Logs a finest gained debug message
	 * 
	 * @access public
	 * @param $msg String|Boolean
	 */
	public function finest($msg){
		if($this->currentLevel >= $this->debugLevel['finest']){
			$this->writeOut("FINEST",$msg);
		}
	}
	
	/**
	 * Logs error that will can be recovered from. 
	 * 
	 * @access public
	 * @param $msg String|Boolean
	 */
	public function warn($msg){
		if($this->currentLevel >= $this->debugLevel['warn']){
			$this->writeOut("WARN",$msg);
		}
	}
	
	/**
	 * Logs a error. The system may be able to continue with some data loss
	 * 
	 * @access public
	 * @param $msg String|Boolean
	 */
	public function error($msg){
		if($this->currentLevel >= $this->debugLevel['error']){
			$this->writeOut("ERROR",$msg);
		}
	}
	
	/**
	 * Logs a critical error, the system will be unable to recover from.
	 * 
	 * @access public
	 * @param $msg String|Boolean
	 */
	public function critical($msg){
		if($this->currentLevel >= $this->debugLevel['critical']){
			$this->writeOut("CRITICAL",$msg);
		}
	}
	
	/**
	 * Appends an error to the error log 
	 * 
	 * @access private
	 * @param $level String
	 * @param $msg String
	 */
	private function writeOut($level, $msg){
		//2008-12-05 12:34:56 - DEBUG - Logger: Error message
		
		global $config;
		if($config->get('debug'))
		{
			//make booleans visible in the logs
			if(is_bool($msg)){
				if($msg){
					$msg = "TRUE";
				}
				else{
					$msg = "FALSE";
				}
			}
			
			$datetime = date('Y-m-d H:i:s');
			$message = $datetime.' - '.$level.' - '.$this->className.': '.$msg;
			
	        $logs = $config->get('logs');
	        $filename = $logs.$this->filename;
			
			if(!file_exists($filename))
	        {
	            //create file
	            $handle = fopen($filename, 'w');
	            $head = 'Stack log file. The Logging verbosity is set using the property $this->configArray["debug"] in config.php. See config.php for valid levels. '."\r\n\r\n\r\n\r\n";
	            fwrite($handle, $head);
	            fclose($handle);
	        }
	
	        if(is_writable($filename))
	        {
	            if(!$handle = fopen($filename, 'a'))
	            {
	               	echo 'Cannot write Log output, '.$filename.' could not be wrote to.';
	            }
	            if(fwrite($handle, "$message \r\n\r\n") == false)
	           	{
	          		echo "Cannot write CAS output to $filename.";
	            }
	       		fclose($handle);
	       	 }
	       	else
	        {
	           echo "Cannot write Logs to $filename.";
	        }
		}
	}	
}
?>