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 Liuggio\StatsdClient\Factory\StatsdDataFactory;
  10 use LoadBalancer;
  11 use MediaWiki\Services\ServiceContainer;
  12 use SiteLookup;
  13 use SiteStore;
  14
  15 /**
  16  * Service locator for MediaWiki core services.
  17  *
  18  * This program is free software; you can redistribute it and/or modify
  19  * it under the terms of the GNU General Public License as published by
  20  * the Free Software Foundation; either version 2 of the License, or
  21  * (at your option) any later version.
  22  *
  23  * This program is distributed in the hope that it will be useful,
  24  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  25  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  26  * GNU General Public License for more details.
  27  *
  28  * You should have received a copy of the GNU General Public License along
  29  * with this program; if not, write to the Free Software Foundation, Inc.,
  30  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  31  * http://www.gnu.org/copyleft/gpl.html
  32  *
  33  * @file
  34  *
  35  * @since 1.27
  36  */
  37
  38 /**
  39  * MediaWikiServices is the service locator for the application scope of MediaWiki.
  40  * Its implemented as a simple configurable DI container.
  41  * MediaWikiServices acts as a top level factory/registry for top level services, and builds
  42  * the network of service objects that defines MediaWiki's application logic.
  43  * It acts as an entry point to MediaWiki's dependency injection mechanism.
  44  *
  45  * Services are defined in the "wiring" array passed to the constructor,
  46  * or by calling defineService().
  47  *
  48  * @see docs/injection.txt for an overview of using dependency injection in the
  49  *      MediaWiki code base.
  50  */
  51 class MediaWikiServices extends ServiceContainer {
  52
  53         /**
  54          * Returns the global default instance of the top level service locator.
  55          *
  56          * The default instance is initialized using the service instantiator functions
  57          * defined in ServiceWiring.php.
  58          *
  59          * @note This should only be called by static functions! The instance returned here
  60          * should not be passed around! Objects that need access to a service should have
  61          * that service injected into the constructor, never a service locator!
  62          *
  63          * @return MediaWikiServices
  64          */
  65         public static function getInstance() {
  66                 static $instance = null;
  67
  68                 if ( $instance === null ) {
  69                         // NOTE: constructing GlobalVarConfig here is not particularly pretty,
  70                         // but some information from the global scope has to be injected here,
  71                         // even if it's just a file name or database credentials to load
  72                         // configuration from.
  73                         $config = new GlobalVarConfig();
  74                         $instance = new self( $config );
  75
  76                         // Load the default wiring from the specified files.
  77                         $wiringFiles = $config->get( 'ServiceWiringFiles' );
  78                         $instance->loadWiringFiles( $wiringFiles );
  79
  80                         // Provide a traditional hook point to allow extensions to configure services.
  81                         Hooks::run( 'MediaWikiServices', [ $instance ] );
  82                 }
  83
  84                 return $instance;
  85         }
  86
  87         /**
  88          * @param Config $config The Config object to be registered as the 'BootstrapConfig' service.
  89          *        This has to contain at least the information needed to set up the 'ConfigFactory'
  90          *        service.
  91          */
  92         public function __construct( Config $config ) {
  93                 parent::__construct();
  94
  95                 // register the given Config object as the bootstrap config service.
  96                 $this->defineService( 'BootstrapConfig', function() use ( $config ) {
  97                         return $config;
  98                 } );
  99         }
 100
 101         /**
 102          * Returns the Config object containing the bootstrap configuration.
 103          * Bootstrap configuration would typically include database credentials
 104          * and other information that may be needed before the ConfigFactory
 105          * service can be instantiated.
 106          *
 107          * @note This should only be used during bootstrapping, in particular
 108          * when creating the MainConfig service. Application logic should
 109          * use getMainConfig() to get a Config instances.
 110          *
 111          * @return Config
 112          */
 113         public function getBootstrapConfig() {
 114                 return $this->getService( 'BootstrapConfig' );
 115         }
 116
 117         /**
 118          * @return ConfigFactory
 119          */
 120         public function getConfigFactory() {
 121                 return $this->getService( 'ConfigFactory' );
 122         }
 123
 124         /**
 125          * Returns the Config object that provides configuration for MediaWiki core.
 126          * This may or may not be the same object that is returned by getBootstrapConfig().
 127          *
 128          * @return Config
 129          */
 130         public function getMainConfig() {
 131                 return $this->getService( 'MainConfig' );
 132         }
 133
 134         /**
 135          * @return SiteLookup
 136          */
 137         public function getSiteLookup() {
 138                 return $this->getService( 'SiteLookup' );
 139         }
 140
 141         /**
 142          * @return SiteStore
 143          */
 144         public function getSiteStore() {
 145                 return $this->getService( 'SiteStore' );
 146         }
 147
 148         /**
 149          * @return StatsdDataFactory
 150          */
 151         public function getStatsdDataFactory() {
 152                 return $this->getService( 'StatsdDataFactory' );
 153         }
 154
 155         ///////////////////////////////////////////////////////////////////////////
 156         // NOTE: When adding a service getter here, don't forget to add a test
 157         // case for it in MediaWikiServicesTest::provideGetters() and in
 158         // MediaWikiServicesTest::provideGetService()!
 159         ///////////////////////////////////////////////////////////////////////////
 160
 161 }