[RESOLVED] log class with 3 functions as a factory

[jrough]

I want to create a log class with three methods. I can write to a text file, write to a log and send email. I want to be able to switch to either of the methods using the $type var.

I have a quetion.

I wanted to make this class a factory so I could create the logs. I'm not sure the factory concept would work in this case but I made it a static function so it can't be instantiated.

public static function Log()
{
return new Log;
}
The class is not done yet but I am trying to understand the factory concept for this case. Thanks,

<?php
require_once "db.php";

class Log
{   

private $fh, $msg, $type;

function __construct($msg){
	 $this->fh = null;
	 $this->type=$type;
	 $this->msg=$new_msg;
}	

public static function Log()
{
	return new Log;	
}

funtion set_message($new_msg){
	$this->msg= $new_msg;
}
function get_message(){
	return $this->msg;
}
public	function logToFile($msg){

		 $fd = fopen($filename, "a");
		 $str = "[" .date("Y/m/d h:i:s", mktme()) . "] " . $msg;
		 fwrite($fd, $str. "\n");
		 $fclose($fd);
         $db     = LogDb::getConnection();

}//end function

public static function logToDb($msg, $type){ 
	// open connection to database
	$db = LogDb::getConnection();

$query = "INSERT INTO log (date, type, msg) VALUES(NOW(),
	'$type', '$msg')";


}//end function
}//end class
function logToMail($msg, $address,$type)
{ 
// append date/time to message
$str = "[" . date("Y/m/d h:i:s", mktime()) . "] " . $msg; 
mail($address, "Log message", $str);
}
$conn = @mysql_connect("localhost", "joe", "pass");
if (!$conn) { logToMail("Could not connect to database",
"[e-mail]"); } 
$a = array("chocolate", "strawberry", "peach");
if (!in_array('fish', $a)) { logToDB("No fish available", 14); }

logFactory::()->writelog();
$v = "Mary had a little lamb";
if (!is_numeric($v)) { logToFile("my.log", "Non-numeric variable
encountered"); }
$a = array("chocolate", "strawberry", "peach");
if (!in_array('fish', $a)) { logToFile("my.log", "No fish available"); }
$conn = @mysql_connect("localhost", "joe", "pass");
if (!$conn)
{
logToFile("my.log", "Could not connect to database");
die("Could not connect to database");
}

[NogDog]

My first thought is to instead create an abstract Log class, then extend it with concrete LogToFile, LogToDb, and LogToEmail classes.

[jrough]

Hi, Thanks for your suggestion about the abstract class. I have been thinking about it and I don't think it fits into the factory method because there aren't so many log types that you would need a factory design pattern for it. The problem was to use a design pattern but I don't know which one fits.
I am trying to work on the class but I first took a step back to make sure I am creating just the first function of the class so it works? I can't figure out how to do the constructor for all of the methods including the ones for the other 3 log functions. Do you do the constructor for all of the vars all at the beginning for all of the log methods?

 Log{

var $filename;
var $msg;
var $fd = null;

public __construct(){
$this->filename = $filename;
$this->msg = $msg;	
}

// open file
function Log(){
	$fd = fopen($filename, "a");
	// append date/time to message
	$str = "[" . date("Y/m/d h:i:s", mktime()) . "] " . $msg; 
	// write string
	fwrite($fd, $str . "\n");
	// close file
	fclose($fd);
}

$logo = new Log;
$v = "Mary had a little lamb";
if (!is_numeric($v)) { $logo->Log("my.log", "Non-numeric variable encountered"); }
$a = array("chocolate", "strawberry", "peach");
if (!in_array('fish', $a)) { $logo->Log("my.log", "No fish available"); }
$conn = @mysql_connect("localhost", "joe", "pass");
if (!$conn){$logo->Log("my.log", "Could not connect to database");
die("Could not connect to database");

[NogDog]

I'll just keep throwing out different ideas until one sticks. 🙂

How about the Strategy pattern?

<?php
interface ILogStrategy
{
   public function log($msg, $destination);
}

class FileLogStrategy implements ILogStrategy
{
   public function log($msg, $destination)
   {
      if(($fh = fopen($destination, 'a'))) {
         fputs($fh, trim($msg)."\n");
         fclose($fh);
      } else {
         user_error("Unalbe to open log file");
      }
   }
}

class EmailLogStrategy implements ILogStrategy
{
   public function log($msg, $destination)
   {
      mail($email, 'PHP error', $msg);
   }
}

class DbLogStrategy implements ILogStrategy
{
   public function log($msg, $destination)
   {
      if(!is_object($destination) or !is_a($destination, 'mysqli')) {
         throw new Exception("Destination must be a MySQLi object");
      }
      $stmt = $destination->prepare("INSERT INTO error_log (message) VALUES(?)");
      $stmt->bindParam('s', $msg);
      $stmt->execute();
   }
}

class Log
{
   private $strategy;
   private $destination;
   public function __construct(ILogStrategy $strategy, $destination)
   {
      $this->strategy = $strategy;
      $this->destination = $destination;
   }
   public function log($msg)
   {
      $this->strategy->log($msg, $this->destination);
   }
}

// USAGE:
$logger = new Log(new FileLogStrategy(), './error_log.txt');
$logger->log("This is a test");