includes/MediaWikiServices.php

   1 <?php
   2 namespace MediaWiki;
   3
   4 use ConfigFactory;
   5 use EventRelayerGroup;
   6 use GlobalVarConfig;
   7 use Config;
   8 use Hooks;
   9 use LBFactory;
  10 use Liuggio\StatsdClient\Factory\StatsdDataFactory;
  11 use LoadBalancer;
  12 use MediaWiki\Services\ServiceContainer;
  13 use SiteLookup;
  14 use SiteStore;
  15
  16 /**
  17  * Service locator for MediaWiki core services.
  18  *
  19  * This program is free software; you can redistribute it and/or modify
  20  * it under the terms of the GNU General Public License as published by
  21  * the Free Software Foundation; either version 2 of the License, or
  22  * (at your option) any later version.
  23  *
  24  * This program is distributed in the hope that it will be useful,
  25  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  26  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  27  * GNU General Public License for more details.
  28  *
  29  * You should have received a copy of the GNU General Public License along
  30  * with this program; if not, write to the Free Software Foundation, Inc.,
  31  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  32  * http://www.gnu.org/copyleft/gpl.html
  33  *
  34  * @file
  35  *
  36  * @since 1.27
  37  */
  38
  39 /**
  40  * MediaWikiServices is the service locator for the application scope of MediaWiki.
  41  * Its implemented as a simple configurable DI container.
  42  * MediaWikiServices acts as a top level factory/registry for top level services, and builds
  43  * the network of service objects that defines MediaWiki's application logic.
  44  * It acts as an entry point to MediaWiki's dependency injection mechanism.
  45  *
  46  * Services are defined in the "wiring" array passed to the constructor,
  47  * or by calling defineService().
  48  *
  49  * @see docs/injection.txt for an overview of using dependency injection in the
  50  *      MediaWiki code base.
  51  */
  52 class MediaWikiServices extends ServiceContainer {
  53
  54         /**
  55          * Returns the global default instance of the top level service locator.
  56          *
  57          * The default instance is initialized using the service instantiator functions
  58          * defined in ServiceWiring.php.
  59          *
  60          * @note This should only be called by static functions! The instance returned here
  61          * should not be passed around! Objects that need access to a service should have
  62          * that service injected into the constructor, never a service locator!
  63          *
  64          * @return MediaWikiServices
  65          */
  66         public static function getInstance() {
  67                 static $instance = null;
  68
  69                 if ( $instance === null ) {
  70                         // NOTE: constructing GlobalVarConfig here is not particularly pretty,
  71                         // but some information from the global scope has to be injected here,
  72                         // even if it's just a file name or database credentials to load
  73                         // configuration from.
  74                         $config = new GlobalVarConfig();
  75                         $instance = new self( $config );
  76
  77                         // Load the default wiring from the specified files.
  78                         $wiringFiles = $config->get( 'ServiceWiringFiles' );
  79                         $instance->loadWiringFiles( $wiringFiles );
  80
  81                         // Provide a traditional hook point to allow extensions to configure services.
  82                         Hooks::run( 'MediaWikiServices', [ $instance ] );
  83                 }
  84
  85                 return $instance;
  86         }
  87
  88         /**
  89          * @param Config $config The Config object to be registered as the 'BootstrapConfig' service.
  90          *        This has to contain at least the information needed to set up the 'ConfigFactory'
  91          *        service.
  92          */
  93         public function __construct( Config $config ) {
  94                 parent::__construct();
  95
  96                 // register the given Config object as the bootstrap config service.
  97                 $this->defineService( 'BootstrapConfig', function() use ( $config ) {
  98                         return $config;
  99                 } );
 100         }
 101
 102         /**
 103          * Returns the Config object containing the bootstrap configuration.
 104          * Bootstrap configuration would typically include database credentials
 105          * and other information that may be needed before the ConfigFactory
 106          * service can be instantiated.
 107          *
 108          * @note This should only be used during bootstrapping, in particular
 109          * when creating the MainConfig service. Application logic should
 110          * use getMainConfig() to get a Config instances.
 111          *
 112          * @return Config
 113          */
 114         public function getBootstrapConfig() {
 115                 return $this->getService( 'BootstrapConfig' );
 116         }
 117
 118         /**
 119          * @return ConfigFactory
 120          */
 121         public function getConfigFactory() {
 122                 return $this->getService( 'ConfigFactory' );
 123         }
 124
 125         /**
 126          * Returns the Config object that provides configuration for MediaWiki core.
 127          * This may or may not be the same object that is returned by getBootstrapConfig().
 128          *
 129          * @return Config
 130          */
 131         public function getMainConfig() {
 132                 return $this->getService( 'MainConfig' );
 133         }
 134
 135         /**
 136          * @return SiteLookup
 137          */
 138         public function getSiteLookup() {
 139                 return $this->getService( 'SiteLookup' );
 140         }
 141
 142         /**
 143          * @return SiteStore
 144          */
 145         public function getSiteStore() {
 146                 return $this->getService( 'SiteStore' );
 147         }
 148
 149         /**
 150          * @return StatsdDataFactory
 151          */
 152         public function getStatsdDataFactory() {
 153                 return $this->getService( 'StatsdDataFactory' );
 154         }
 155
 156         /**
 157          * @return EventRelayerGroup
 158          */
 159         public function getEventRelayerGroup() {
 160                 return $this->getService( 'EventRelayerGroup' );
 161         }
 162
 163         /**
 164          * @return SearchEngine
 165          */
 166         public function newSearchEngine() {
 167                 // New engine object every time, since they keep state
 168                 return $this->getService( 'SearchEngineFactory' )->create();
 169         }
 170
 171         /**
 172          * @return SearchEngineFactory
 173          */
 174         public function getSearchEngineFactory() {
 175                 return $this->getService( 'SearchEngineFactory' );
 176         }
 177
 178         /**
 179          * @return SearchEngineConfig
 180          */
 181         public function getSearchEngineConfig() {
 182                 return $this->getService( 'SearchEngineConfig' );
 183         }
 184
 185         ///////////////////////////////////////////////////////////////////////////
 186         // NOTE: When adding a service getter here, don't forget to add a test
 187         // case for it in MediaWikiServicesTest::provideGetters() and in
 188         // MediaWikiServicesTest::provideGetService()!
 189         ///////////////////////////////////////////////////////////////////////////
 190
 191 }