LoggerChannelFactory.php

<?php

namespace Drupal\Core\Logger;

use Psr\Log\LoggerInterface;
use Symfony\Component\DependencyInjection\ContainerAwareInterface;
use Symfony\Component\DependencyInjection\ContainerAwareTrait;

/**
 * Defines a factory for logging channels.
 */
class LoggerChannelFactory implements LoggerChannelFactoryInterface, ContainerAwareInterface {
    use ContainerAwareTrait;
    
    /**
     * Array of all instantiated logger channels keyed by channel name.
     *
     * @var \Drupal\Core\Logger\LoggerChannelInterface[]
     */
    protected $channels = [];
    
    /**
     * An array of arrays of \Psr\Log\LoggerInterface keyed by priority.
     *
     * @var array
     */
    protected $loggers = [];
    
    /**
     * {@inheritdoc}
     */
    public function get($channel) {
        if (!isset($this->channels[$channel])) {
            $instance = new LoggerChannel($channel);
            // If we have a container set the request_stack and current_user services
            // on the channel. It is up to the channel to determine if there is a
            // current request.
            if ($this->container) {
                $instance->setRequestStack($this->container
                    ->get('request_stack'));
                $instance->setCurrentUser($this->container
                    ->get('current_user'));
            }
            // Pass the loggers to the channel.
            $instance->setLoggers($this->loggers);
            $this->channels[$channel] = $instance;
        }
        return $this->channels[$channel];
    }
    
    /**
     * {@inheritdoc}
     */
    public function addLogger(LoggerInterface $logger, $priority = 0) {
        // Store it so we can pass it to potential new logger instances.
        $this->loggers[$priority][] = $logger;
        // Add the logger to already instantiated channels.
        foreach ($this->channels as $channel) {
            $channel->addLogger($logger, $priority);
        }
    }

}