RfcLogLevel.php

<?php

namespace Drupal\Core\Logger;

use Drupal\Core\StringTranslation\TranslatableMarkup;

/**
 * @defgroup logging_severity_levels Logging severity levels
 * @{
 * Logging severity levels as defined in RFC 5424.
 *
 * The constant definitions of this class correspond to the logging severity
 * levels defined in RFC 5424, section 6.2.1. PHP supplies predefined LOG_*
 * constants for use in the syslog() function, but their values on Windows
 * builds do not correspond to RFC 5424. The associated PHP bug report was
 * closed with the comment, "And it's also not a bug, as Windows just have less
 * log levels," and "So the behavior you're seeing is perfectly normal."
 *
 * @see https://tools.ietf.org/html/rfc5424#section-6.2.1
 * @see http://bugs.php.net/bug.php?id=18090
 * @see http://php.net/manual/function.syslog.php
 * @see http://php.net/manual/network.constants.php
 * @see \Drupal\Core\Logger\RfcLogLevel::getLevels()
 *
 * @}
 */

/**
 * Defines various logging severity levels.
 *
 * @ingroup logging_severity_levels
 */
class RfcLogLevel {
    
    /**
     * Log message severity -- Emergency: system is unusable.
     */
    const EMERGENCY = 0;
    
    /**
     * Log message severity -- Alert: action must be taken immediately.
     */
    const ALERT = 1;
    
    /**
     * Log message severity -- Critical conditions.
     */
    const CRITICAL = 2;
    
    /**
     * Log message severity -- Error conditions.
     */
    const ERROR = 3;
    
    /**
     * Log message severity -- Warning conditions.
     */
    const WARNING = 4;
    
    /**
     * Log message severity -- Normal but significant conditions.
     */
    const NOTICE = 5;
    
    /**
     * Log message severity -- Informational messages.
     */
    const INFO = 6;
    
    /**
     * Log message severity -- Debug-level messages.
     */
    const DEBUG = 7;
    
    /**
     * An array with the severity levels as keys and labels as values.
     *
     * @var array
     */
    protected static $levels;
    
    /**
     * Returns a list of severity levels, as defined in RFC 5424.
     *
     * @return array
     *   Array of the possible severity levels for log messages.
     *
     * @see http://tools.ietf.org/html/rfc5424
     * @ingroup logging_severity_levels
     */
    public static function getLevels() {
        if (!static::$levels) {
            static::$levels = [
                static::EMERGENCY => new TranslatableMarkup('Emergency'),
                static::ALERT => new TranslatableMarkup('Alert'),
                static::CRITICAL => new TranslatableMarkup('Critical'),
                static::ERROR => new TranslatableMarkup('Error'),
                static::WARNING => new TranslatableMarkup('Warning'),
                static::NOTICE => new TranslatableMarkup('Notice'),
                static::INFO => new TranslatableMarkup('Info'),
                static::DEBUG => new TranslatableMarkup('Debug'),
            ];
        }
        return static::$levels;
    }

}