includes/MediaWikiServices.php

   1 <?php
   2 namespace MediaWiki;
   3
   4 use ConfigFactory;
   5 use GlobalVarConfig;
   6 use Config;
   7 use Hooks;
   8 use LBFactory;
   9 use LoadBalancer;
  10 use MediaWiki\Services\ServiceContainer;
  11 use SiteLookup;
  12 use SiteStore;
  13
  14 /**
  15  * Service locator for MediaWiki core services.
  16  *
  17  * This program is free software; you can redistribute it and/or modify
  18  * it under the terms of the GNU General Public License as published by
  19  * the Free Software Foundation; either version 2 of the License, or
  20  * (at your option) any later version.
  21  *
  22  * This program is distributed in the hope that it will be useful,
  23  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  25  * GNU General Public License for more details.
  26  *
  27  * You should have received a copy of the GNU General Public License along
  28  * with this program; if not, write to the Free Software Foundation, Inc.,
  29  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  30  * http://www.gnu.org/copyleft/gpl.html
  31  *
  32  * @file
  33  *
  34  * @since 1.27
  35  */
  36
  37 /**
  38  * MediaWikiServices is the service locator for the application scope of MediaWiki.
  39  * Its implemented as a simple configurable DI container.
  40  * MediaWikiServices acts as a top level factory/registry for top level services, and builds
  41  * the network of service objects that defines MediaWiki's application logic.
  42  * It acts as an entry point to MediaWiki's dependency injection mechanism.
  43  *
  44  * Services are defined in the "wiring" array passed to the constructor,
  45  * or by calling defineService().
  46  *
  47  * @see docs/injection.txt for an overview of using dependency injection in the
  48  *      MediaWiki code base.
  49  */
  50 class MediaWikiServices extends ServiceContainer {
  51
  52         /**
  53          * Returns the global default instance of the top level service locator.
  54          *
  55          * The default instance is initialized using the service instantiator functions
  56          * defined in ServiceWiring.php.
  57          *
  58          * @note This should only be called by static functions! The instance returned here
  59          * should not be passed around! Objects that need access to a service should have
  60          * that service injected into the constructor, never a service locator!
  61          *
  62          * @return MediaWikiServices
  63          */
  64         public static function getInstance() {
  65                 static $instance = null;
  66
  67                 if ( $instance === null ) {
  68                         // NOTE: constructing GlobalVarConfig here is not particularly pretty,
  69                         // but some information from the global scope has to be injected here,
  70                         // even if it's just a file name or database credentials to load
  71                         // configuration from.
  72                         $config = new GlobalVarConfig();
  73                         $instance = new self( $config );
  74
  75                         // Load the default wiring from the specified files.
  76                         $wiringFiles = $config->get( 'ServiceWiringFiles' );
  77                         $instance->loadWiringFiles( $wiringFiles );
  78
  79                         // Provide a traditional hook point to allow extensions to configure services.
  80                         Hooks::run( 'MediaWikiServices', [ $instance ] );
  81                 }
  82
  83                 return $instance;
  84         }
  85
  86         /**
  87          * @param Config $config The Config object to be registered as the 'BootstrapConfig' service.
  88          *        This has to contain at least the information needed to set up the 'ConfigFactory'
  89          *        service.
  90          */
  91         public function __construct( Config $config ) {
  92                 parent::__construct();
  93
  94                 // register the given Config object as the bootstrap config service.
  95                 $this->defineService( 'BootstrapConfig', function() use ( $config ) {
  96                         return $config;
  97                 } );
  98         }
  99
 100         /**
 101          * Returns the Config object containing the bootstrap configuration.
 102          * Bootstrap configuration would typically include database credentials
 103          * and other information that may be needed before the ConfigFactory
 104          * service can be instantiated.
 105          *
 106          * @note This should only be used during bootstrapping, in particular
 107          * when creating the MainConfig service. Application logic should
 108          * use getMainConfig() to get a Config instances.
 109          *
 110          * @return Config
 111          */
 112         public function getBootstrapConfig() {
 113                 return $this->getService( 'BootstrapConfig' );
 114         }
 115
 116         /**
 117          * @return ConfigFactory
 118          */
 119         public function getConfigFactory() {
 120                 return $this->getService( 'ConfigFactory' );
 121         }
 122
 123         /**
 124          * Returns the Config object that provides configuration for MediaWiki core.
 125          * This may or may not be the same object that is returned by getBootstrapConfig().
 126          *
 127          * @return Config
 128          */
 129         public function getMainConfig() {
 130                 return $this->getService( 'MainConfig' );
 131         }
 132
 133         /**
 134          * @return SiteLookup
 135          */
 136         public function getSiteLookup() {
 137                 return $this->getService( 'SiteLookup' );
 138         }
 139
 140         /**
 141          * @return SiteStore
 142          */
 143         public function getSiteStore() {
 144                 return $this->getService( 'SiteStore' );
 145         }
 146
 147         ///////////////////////////////////////////////////////////////////////////
 148         // NOTE: When adding a service getter here, don't forget to add a test
 149         // case for it in MediaWikiServicesTest::provideGetters() and in
 150         // MediaWikiServicesTest::provideGetService()!
 151         ///////////////////////////////////////////////////////////////////////////
 152
 153 }