This is a very simple class that will allow your scripts to log to a file, i will also show how to extend this class so that you can have multiple data sources.
This class is using a singleton pattern at the moment, this is done so that no more than one instance of this class can be instanciated at any time.
<?php
final class Logger {
private static $_instance;
private function __construct() {
}
static function instance() {
if (!isset(self::$_instance)) {
$c = __CLASS__;
self::$_instance = new $c;
}
return self::$_instance;
}
// Prevent users to clone the instance
public function __clone() {
throw new Exception('Cannot clone the logger object.');
}
public function log($message = '') {
$filename = BASE_PATH.'/log.txt';
$file = fopen($filename, 'a+');
fwrite($file, $message."\r\n");
fclose($file);
}
}
?>
to use this you would do something like the following
Now what if you wanted to be able to store the stuff in the database? You could easilly extend the class as such
<?php
abstract class Logger {
public function __construct() {
}
abstract function log($message = '') {
}
}
class FileLogger extends Logger {
public function __construct() {
}
public function log($message = '') {
$filename = BASE_PATH.'/log.txt';
$file = fopen($filename, 'a+');
fwrite($file, $message."\r\n");
fclose($file);
}
}
class DatabaseLogger extends Logger {
private $_db;
public function __construct($db = NULL) {
if($db instanceof Database) $this->_db = $db;
else throw new Exception(__METHOD__ . ' requires an object of type Database');
}
public function log($message = NULL) {
if(!is_null($message) && $message != '') $this->_db->Query("INSERT INTO log (message) VALUES('".$message."')");
}
}
?>
Now when you want to use this you would do something like the following example
<?php
$log = new FileLogger();
$log->log('Writing to a file');
$log = new DatabaseLogger($db_obj);
$log->log('Writing to the database.');
$log = null;
?>
I hope this example has helped people :) I know it's simple but i mainly submitted it to show how to easilly extend objects in PHP5 I have one more that i will submit that may show a better example ;)
Enjoy.
