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 SearchEngine;
  14 use SearchEngineConfig;
  15 use SearchEngineFactory;
  16 use SiteLookup;
  17 use SiteStore;
  18
  19 /**
  20  * Service locator for MediaWiki core services.
  21  *
  22  * This program is free software; you can redistribute it and/or modify
  23  * it under the terms of the GNU General Public License as published by
  24  * the Free Software Foundation; either version 2 of the License, or
  25  * (at your option) any later version.
  26  *
  27  * This program is distributed in the hope that it will be useful,
  28  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  29  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  30  * GNU General Public License for more details.
  31  *
  32  * You should have received a copy of the GNU General Public License along
  33  * with this program; if not, write to the Free Software Foundation, Inc.,
  34  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  35  * http://www.gnu.org/copyleft/gpl.html
  36  *
  37  * @file
  38  *
  39  * @since 1.27
  40  */
  41
  42 /**
  43  * MediaWikiServices is the service locator for the application scope of MediaWiki.
  44  * Its implemented as a simple configurable DI container.
  45  * MediaWikiServices acts as a top level factory/registry for top level services, and builds
  46  * the network of service objects that defines MediaWiki's application logic.
  47  * It acts as an entry point to MediaWiki's dependency injection mechanism.
  48  *
  49  * Services are defined in the "wiring" array passed to the constructor,
  50  * or by calling defineService().
  51  *
  52  * @see docs/injection.txt for an overview of using dependency injection in the
  53  *      MediaWiki code base.
  54  */
  55 class MediaWikiServices extends ServiceContainer {
  56
  57         /**
  58          * Returns the global default instance of the top level service locator.
  59          *
  60          * The default instance is initialized using the service instantiator functions
  61          * defined in ServiceWiring.php.
  62          *
  63          * @note This should only be called by static functions! The instance returned here
  64          * should not be passed around! Objects that need access to a service should have
  65          * that service injected into the constructor, never a service locator!
  66          *
  67          * @return MediaWikiServices
  68          */
  69         public static function getInstance() {
  70                 static $instance = null;
  71
  72                 if ( $instance === null ) {
  73                         // NOTE: constructing GlobalVarConfig here is not particularly pretty,
  74                         // but some information from the global scope has to be injected here,
  75                         // even if it's just a file name or database credentials to load
  76                         // configuration from.
  77                         $config = new GlobalVarConfig();
  78                         $instance = new self( $config );
  79
  80                         // Load the default wiring from the specified files.
  81                         $wiringFiles = $config->get( 'ServiceWiringFiles' );
  82                         $instance->loadWiringFiles( $wiringFiles );
  83
  84                         // Provide a traditional hook point to allow extensions to configure services.
  85                         Hooks::run( 'MediaWikiServices', [ $instance ] );
  86                 }
  87
  88                 return $instance;
  89         }
  90
  91         /**
  92          * @param Config $config The Config object to be registered as the 'BootstrapConfig' service.
  93          *        This has to contain at least the information needed to set up the 'ConfigFactory'
  94          *        service.
  95          */
  96         public function __construct( Config $config ) {
  97                 parent::__construct();
  98
  99                 // register the given Config object as the bootstrap config service.
 100                 $this->defineService( 'BootstrapConfig', function() use ( $config ) {
 101                         return $config;
 102                 } );
 103         }
 104
 105         /**
 106          * Returns the Config object containing the bootstrap configuration.
 107          * Bootstrap configuration would typically include database credentials
 108          * and other information that may be needed before the ConfigFactory
 109          * service can be instantiated.
 110          *
 111          * @note This should only be used during bootstrapping, in particular
 112          * when creating the MainConfig service. Application logic should
 113          * use getMainConfig() to get a Config instances.
 114          *
 115          * @return Config
 116          */
 117         public function getBootstrapConfig() {
 118                 return $this->getService( 'BootstrapConfig' );
 119         }
 120
 121         /**
 122          * @return ConfigFactory
 123          */
 124         public function getConfigFactory() {
 125                 return $this->getService( 'ConfigFactory' );
 126         }
 127
 128         /**
 129          * Returns the Config object that provides configuration for MediaWiki core.
 130          * This may or may not be the same object that is returned by getBootstrapConfig().
 131          *
 132          * @return Config
 133          */
 134         public function getMainConfig() {
 135                 return $this->getService( 'MainConfig' );
 136         }
 137
 138         /**
 139          * @return SiteLookup
 140          */
 141         public function getSiteLookup() {
 142                 return $this->getService( 'SiteLookup' );
 143         }
 144
 145         /**
 146          * @return SiteStore
 147          */
 148         public function getSiteStore() {
 149                 return $this->getService( 'SiteStore' );
 150         }
 151
 152         /**
 153          * @return StatsdDataFactory
 154          */
 155         public function getStatsdDataFactory() {
 156                 return $this->getService( 'StatsdDataFactory' );
 157         }
 158
 159         /**
 160          * @return EventRelayerGroup
 161          */
 162         public function getEventRelayerGroup() {
 163                 return $this->getService( 'EventRelayerGroup' );
 164         }
 165
 166         /**
 167          * @return SearchEngine
 168          */
 169         public function newSearchEngine() {
 170                 // New engine object every time, since they keep state
 171                 return $this->getService( 'SearchEngineFactory' )->create();
 172         }
 173
 174         /**
 175          * @return SearchEngineFactory
 176          */
 177         public function getSearchEngineFactory() {
 178                 return $this->getService( 'SearchEngineFactory' );
 179         }
 180
 181         /**
 182          * @return SearchEngineConfig
 183          */
 184         public function getSearchEngineConfig() {
 185                 return $this->getService( 'SearchEngineConfig' );
 186         }
 187
 188         ///////////////////////////////////////////////////////////////////////////
 189         // NOTE: When adding a service getter here, don't forget to add a test
 190         // case for it in MediaWikiServicesTest::provideGetters() and in
 191         // MediaWikiServicesTest::provideGetService()!
 192         ///////////////////////////////////////////////////////////////////////////
 193
 194 }