monolog/logger error magento

Question

can anybody help on this :

(Psr\Log\InvalidArgumentException): Level "" is not defined, use one of: 100, 200, 250, 300, 400, 500, 550, 600
vendor\monolog\monolog\src\Monolog\Logger.php(256): Monolog\Logger::getLevelName(NULL) lib\internal\Magento\Framework\Logger\Monolog.php(24): Monolog\Logger->addRecord(NULL, 'Tagalys Request...', Array)

This is how i have used logger

protected $logger;
public function __construct(
\Psr\Log\LoggerInterface $logger,
 ) {
     $this->logger = $logger;   
   }

public function xyz(){
$this->logger->log(null, 'Tagalys Request Object: '.json_encode($payload)); 
} 

I am not getting any log files

Answer 1

When you use the \Psr\Log\LoggerInterface the first parameter must be a level of log.

Different levels can be found under Psr\Log\LogLevel :

class LogLevel
{
    const EMERGENCY = 'emergency';
    const ALERT = 'alert';
    const CRITICAL = 'critical';
    const ERROR = 'error';
    const WARNING = 'warning';
    const NOTICE = 'notice';
    const INFO = 'info';
    const DEBUG = 'debug';
}

So if you want to log for example a debug information you'll have to call:

$this->logger->log(\Psr\Log\LogLevel::DEBUG, 'Tagalys Request Object: '.json_encode($payload));

To avoid having to specify the level of log, the class provides one method per level so instead of the code above, you can also do:

$this->logger->debug('Tagalys Request Object: '.json_encode($payload));

The other methods available are:

• emergency()
• alert()
• critical()
• error()
• warning()
• notice()
• info()

Using this class you cannot specify a custom log file.

If you want to do so you can use the following code:

$writer = new \Zend\Log\Writer\Stream(BP . '/var/log/mylogfile.log');
$logger = new \Zend\Log\Logger();
$logger->addWriter($writer);
$logger->info('Your text message');