includes/debug/logger/LoggerFactory.php

   1 <?php
   2 /**
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  16  * http://www.gnu.org/copyleft/gpl.html
  17  *
  18  * @file
  19  */
  20
  21 namespace MediaWiki\Logger;
  22
  23 use ObjectFactory;
  24
  25 /**
  26  * PSR-3 logger instance factory.
  27  *
  28  * Creation of \\Psr\\Log\\LoggerInterface instances is managed via the
  29  * LoggerFactory::getInstance() static method which in turn delegates to the
  30  * currently registered service provider.
  31  *
  32  * A service provider is any class implementing the Spi interface.
  33  * There are two possible methods of registering a service provider. The
  34  * LoggerFactory::registerProvider() static method can be called at any time
  35  * to change the service provider. If LoggerFactory::getInstance() is called
  36  * before any service provider has been registered, it will attempt to use the
  37  * $wgMWLoggerDefaultSpi global to bootstrap Spi registration.
  38  * $wgMWLoggerDefaultSpi is expected to be an array usable by
  39  * ObjectFactory::getObjectFromSpec() to create a class.
  40  *
  41  * @see \\MediaWiki\\Logger\\Spi
  42  * @since 1.25
  43  * @author Bryan Davis <bd808@wikimedia.org>
  44  * @copyright © 2014 Bryan Davis and Wikimedia Foundation.
  45  */
  46 class LoggerFactory {
  47
  48         /**
  49          * Service provider.
  50          * @var \MediaWiki\Logger\Spi $spi
  51          */
  52         private static $spi;
  53
  54
  55         /**
  56          * Register a service provider to create new \\Psr\\Log\\LoggerInterface
  57          * instances.
  58          *
  59          * @param \\MediaWiki\\Logger\\Spi $provider Provider to register
  60          */
  61         public static function registerProvider( Spi $provider ) {
  62                 self::$spi = $provider;
  63         }
  64
  65
  66         /**
  67          * Get the registered service provider.
  68          *
  69          * If called before any service provider has been registered, it will
  70          * attempt to use the $wgMWLoggerDefaultSpi global to bootstrap
  71          * Spi registration. $wgMWLoggerDefaultSpi is expected to be an
  72          * array usable by ObjectFactory::getObjectFromSpec() to create a class.
  73          *
  74          * @return \\MediaWiki\\Logger\\Spi
  75          * @see registerProvider()
  76          * @see ObjectFactory::getObjectFromSpec()
  77          */
  78         public static function getProvider() {
  79                 if ( self::$spi === null ) {
  80                         global $wgMWLoggerDefaultSpi;
  81                         $provider = ObjectFactory::getObjectFromSpec(
  82                                 $wgMWLoggerDefaultSpi
  83                         );
  84                         self::registerProvider( $provider );
  85                 }
  86                 return self::$spi;
  87         }
  88
  89
  90         /**
  91          * Get a named logger instance from the currently configured logger factory.
  92          *
  93          * @param string $channel Logger channel (name)
  94          * @return \\Psr\\Log\\LoggerInterface
  95          */
  96         public static function getInstance( $channel ) {
  97                 if ( !interface_exists( '\Psr\Log\LoggerInterface' ) ) {
  98                         $message = (
  99                                 'MediaWiki requires the <a href="https://github.com/php-fig/log">PSR-3 logging ' .
 100                                 "library</a> to be present. This library is not embedded directly in MediaWiki's " .
 101                                 "git repository and must be installed separately by the end user.\n\n" .
 102                                 'Please see <a href="https://www.mediawiki.org/wiki/Download_from_Git' .
 103                                 '#Fetch_external_libraries">mediawiki.org</a> for help on installing ' .
 104                                 'the required components.'
 105                         );
 106                         echo $message;
 107                         trigger_error( $message, E_USER_ERROR );
 108                         die( 1 );
 109                 }
 110
 111                 return self::getProvider()->getLogger( $channel );
 112         }
 113
 114
 115         /**
 116          * Construction of utility class is not allowed.
 117          */
 118         private function __construct() {
 119                 // no-op
 120         }
 121 }