Magento 2 – How to Write log

Logging is an important part of any development process. Logs assist you to spot an error and the reason for it. Magento 2 contains built-in logging solution based on Monolog Library.

To start working with a logger, you must create an instance of \Psr\Log\LoggerInterface. With this interface, you can call the following functions to write data to log files:

alert()
critical()
debug()
emergency()
error()
info()
log()
notice()
warning()

All log methods contains 2 arguments, first one is the message text and the second one is an optional array.

$this->_logger-> emergency($message);
//saved in var/log/system.log

$this->_logger-> alert($message);
//saved in var/log/system.log
 
$this->_logger-> critical($message);
//saved in var/log/system.log
 
$this->_logger-> error($message);
//saved in var/log/system.log
 
$this->_logger-> warning($message);
//saved in  var/log/system.log
 
$this->_logger-> notice($message);
//saved in var/log/system.log
 
$this->_logger-> info($message);
//saved in var/log/system.log
 
$this->_logger-> debug($message);
//saved in var/log/debug.log

Note: The degug log is not generate when your Magento 2 website is in production mode.

Below is an example of how to use logger in a custom method and how to log an exception.

protected $_logger;
    
public function __construct(
	\Magento\Backend\Block\Template\Context $context,
	\Psr\Log\LoggerInterface $logger,
	array $data = []
)
{        
	$this->_logger = $logger;
	parent::__construct($context, $data);
}

public function customMethod()
{
	$this->_logger->info('Info Message');
	
	// Log as an Exception
	try {
		//do something
	} catch (\Exception $e) {
		$this->_logger->critical('Something went wrong', ['exception' => $e]);
	}
}

Thats it. Enjoy Magento 2!!

Team HiddenTechies

Write an article about ecommerce that help people to grow their ecommerce business. You’ll find best ecommerce guide, news, tips & more!