Logger Object - Variable Scope - access to Class/Function/etc - php

Question

So I want to find the best method of allowing my Logger class to access any part of the script either another class/function/etc... How would I do this? How do I make it global.
Could I do something like this:
Logger::info('Add message like this?');
Calling script: calling.php
require_once('Logger.class.php'); // Just adding the class initializes the Logger Object
require_once('Another.class.php');
require_once('Functions.php');
$logEntry->info("Log info");
$logEntry->error("Log error");
$logEntry->warning("Log warning");
$logEntry->notice("Log notice");
$logEntry->enableDebug(); // prints debug to log
$logEntry->debug("Log debug enabled");
$logEntry->disableDebug();
$logEntry->debug("Log debug disabled"); // will not print to log
$another_obj = new Another(); // want the Logger to have access inside this class
More(); // want the Logger to have access inside this function
Another.class.php
class Another {
private $var;
// I want to add the Logger here
$logEntry->info("Another Log");
// More code here it's just an example ...
}
Functions.php
function More() {
// I want to add the Logger here
$logEntry->info("More Log");
}
Here is the Logger.class.php script
<?php
//Define Constants
define("LOG_FILE_DIRECTORY", "/var/www/logs");
ini_set("memory_limit","128M"); // Logger class is taking up memory
class Logger {
private $log_file_directory = LOG_FILE_DIRECTORY;
private $first_run; // Flag to add line break at the beginning of script execution
private $calling_script; // Base name of the calling script
private $log_file; // log file path and name
private $log_entry; // information to be logged
private $log_level; // Log severity levels: error, warning, notice, debug, info
private $fh; // File handle
private $file_name; // File path and name
private $file_parts; // Array of $file_name
private $script_name; // Script Name
private $script_parts; // Array of $script_name
private $line_number_arr; // Line number of where the logging event occurred
private $debug_flag; // Set to true if you want to log your debug logger
function __construct() {
$this->first_run = true;
$this->debug_flag = false;
$this->calling_script = '';
$this->log_file = '';
$this->log_entry = '';
$this->log_level = '';
$this->fh = '';
$this->file_name = '';
$this->file_parts = '';
$this->script_name = '';
$this->script_parts = '';
$this->line_number_arr = '';
}
/**
* #enableDebug
*/
public function enableDebug() {
$this->debug_flag = true;
}
/**
* #disbaleDebug
*/
public function disableDebug() {
$this->debug_flag = false;
}
/**
* #info
*/
public function info($message) {
$this->log_level = 'info';
$this->line_number_arr = debug_backtrace();
$this->addEntry($message);
}
/**
* #error
*/
public function error($message) {
$this->log_level = 'error';
$this->line_number_arr = debug_backtrace();
$this->addEntry($message);
}
/**
* #warning
*/
public function warning($message) {
$this->log_level = 'warning';
$this->line_number_arr = debug_backtrace();
$this->addEntry($message);
}
/**
* #notice
*/
public function notice($message) {
$this->log_level = 'notice';
$this->line_number_arr = debug_backtrace();
$this->addEntry($message);
}
/**
* #debug
* must add the below to the script you wish to debug
* define("DEBUG", true); // true enables, false disables
*/
public function debug($message) {
if($this->debug_flag) {
$this->log_level = 'debug';
$this->line_number_arr = debug_backtrace();
$this->addEntry($message);
}
}
private function addEntry($message) {
$this->calling_script = $this->getScriptBaseName();
$this->log_file = $this->log_file_directory."/".$this->calling_script.".log";
$this->fh = fopen($this->log_file, 'a') or die("Can't open log file: ".$this->log_file);
if($this->first_run) {
$this->log_entry = "\n[" . date("Y-m-d H:i:s", mktime()) . "][line:".$this->line_number_arr[0]['line']."|".$this->log_level."]:\t".$message."\n";
} else {
$this->log_entry = "[" . date("Y-m-d H:i:s", mktime()) . "][line:".$this->line_number_arr[0]['line']."|".$this->log_level."]:\t".$message."\n";
}
fwrite($this->fh, $this->log_entry);
fclose($this->fh);
$this->first_run = false;
}
/**
* return the base name of the calling script
*/
private function getScriptBaseName() {
$this->file_name = $_SERVER["SCRIPT_NAME"];
$this->file_parts = explode('/', $this->file_name);
$this->script_name = $this->file_parts[count($this->file_parts) - 1];
$this->script_parts = explode('.', $this->script_name);
// If file doesn't exists don't add line break
if(!file_exists($this->script_parts[0].".log")) {
$this->first_run = false;
}
return $this->script_parts[0];
}
}
// Start log instance
$logEntry = new Logger();
?>

Answer 1

You could implement it as a class full of static functions, e.g.:
class Logger {
protected $logfile = null;
public static load() {
self::$logfile = fopen('error.log', 'a');
}
public static info($msg) {
if(self::$logfile == null)
self::load();
fwrite(self::$logfile, $msg);
}
}
and then use it with Logger::info("My message..");. Another common method of doing this is using a singleton class, so that you can only create a single object of "Logger" and retrieve it using e.g. Logger::getInstance()->logInfo("My message");.
In your case (as you already implemented Logger as a normal class) I would make the __construct private and implement the class as a singleton. It's not possible to make $logEntry globally available. Your code would become:
<?php
//Define Constants
define("LOG_FILE_DIRECTORY", "/var/www/logs");
ini_set("memory_limit","128M"); // Logger class is taking up memory
class Logger {
private $log_file_directory = LOG_FILE_DIRECTORY;
private $first_run; // Flag to add line break at the beginning of script execution
private $calling_script; // Base name of the calling script
private $log_file; // log file path and name
private $log_entry; // information to be logged
private $log_level; // Log severity levels: error, warning, notice, debug, info
private $fh; // File handle
private $file_name; // File path and name
private $file_parts; // Array of $file_name
private $script_name; // Script Name
private $script_parts; // Array of $script_name
private $line_number_arr; // Line number of where the logging event occurred
private $debug_flag; // Set to true if you want to log your debug logger
private static $instance = null;
private function __construct() {
$this->first_run = true;
$this->debug_flag = false;
$this->calling_script = '';
$this->log_file = '';
$this->log_entry = '';
$this->log_level = '';
$this->fh = '';
$this->file_name = '';
$this->file_parts = '';
$this->script_name = '';
$this->script_parts = '';
$this->line_number_arr = '';
}
public static function getInstance() {
if (!isset(self::$instance)) {
$c = __CLASS__;
self::$instance = new $c;
}
return self::$instance;
}
/**
* #enableDebug
*/
public function enableDebug() {
$this->debug_flag = true;
}
/**
* #disbaleDebug
*/
public function disableDebug() {
$this->debug_flag = false;
}
/**
* #info
*/
public function info($message) {
$this->log_level = 'info';
$this->line_number_arr = debug_backtrace();
$this->addEntry($message);
}
/**
* #error
*/
public function error($message) {
$this->log_level = 'error';
$this->line_number_arr = debug_backtrace();
$this->addEntry($message);
}
/**
* #warning
*/
public function warning($message) {
$this->log_level = 'warning';
$this->line_number_arr = debug_backtrace();
$this->addEntry($message);
}
/**
* #notice
*/
public function notice($message) {
$this->log_level = 'notice';
$this->line_number_arr = debug_backtrace();
$this->addEntry($message);
}
/**
* #debug
* must add the below to the script you wish to debug
* define("DEBUG", true); // true enables, false disables
*/
public function debug($message) {
if($this->debug_flag) {
$this->log_level = 'debug';
$this->line_number_arr = debug_backtrace();
$this->addEntry($message);
}
}
private function addEntry($message) {
$this->calling_script = $this->getScriptBaseName();
$this->log_file = $this->log_file_directory."/".$this->calling_script.".log";
$this->fh = fopen($this->log_file, 'a') or die("Can't open log file: ".$this->log_file);
if($this->first_run) {
$this->log_entry = "\n[" . date("Y-m-d H:i:s", mktime()) . "][line:".$this->line_number_arr[0]['line']."|".$this->log_level."]:\t".$message."\n";
} else {
$this->log_entry = "[" . date("Y-m-d H:i:s", mktime()) . "][line:".$this->line_number_arr[0]['line']."|".$this->log_level."]:\t".$message."\n";
}
fwrite($this->fh, $this->log_entry);
fclose($this->fh);
$this->first_run = false;
}
/**
* return the base name of the calling script
*/
private function getScriptBaseName() {
$this->file_name = $_SERVER["SCRIPT_NAME"];
$this->file_parts = explode('/', $this->file_name);
$this->script_name = $this->file_parts[count($this->file_parts) - 1];
$this->script_parts = explode('.', $this->script_name);
// If file doesn't exists don't add line break
if(!file_exists($this->script_parts[0].".log")) {
$this->first_run = false;
}
return $this->script_parts[0];
}
}
?>
You would then use your class globally using Logger::getInstance()->info($msg);