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 use SkinFactory;
  16
  17 /**
  18  * Service locator for MediaWiki core services.
  19  *
  20  * This program is free software; you can redistribute it and/or modify
  21  * it under the terms of the GNU General Public License as published by
  22  * the Free Software Foundation; either version 2 of the License, or
  23  * (at your option) any later version.
  24  *
  25  * This program is distributed in the hope that it will be useful,
  26  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  27  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  28  * GNU General Public License for more details.
  29  *
  30  * You should have received a copy of the GNU General Public License along
  31  * with this program; if not, write to the Free Software Foundation, Inc.,
  32  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  33  * http://www.gnu.org/copyleft/gpl.html
  34  *
  35  * @file
  36  *
  37  * @since 1.27
  38  */
  39
  40 /**
  41  * MediaWikiServices is the service locator for the application scope of MediaWiki.
  42  * Its implemented as a simple configurable DI container.
  43  * MediaWikiServices acts as a top level factory/registry for top level services, and builds
  44  * the network of service objects that defines MediaWiki's application logic.
  45  * It acts as an entry point to MediaWiki's dependency injection mechanism.
  46  *
  47  * Services are defined in the "wiring" array passed to the constructor,
  48  * or by calling defineService().
  49  *
  50  * @see docs/injection.txt for an overview of using dependency injection in the
  51  *      MediaWiki code base.
  52  */
  53 class MediaWikiServices extends ServiceContainer {
  54
  55         /**
  56          * Returns the global default instance of the top level service locator.
  57          *
  58          * The default instance is initialized using the service instantiator functions
  59          * defined in ServiceWiring.php.
  60          *
  61          * @note This should only be called by static functions! The instance returned here
  62          * should not be passed around! Objects that need access to a service should have
  63          * that service injected into the constructor, never a service locator!
  64          *
  65          * @return MediaWikiServices
  66          */
  67         public static function getInstance() {
  68                 static $instance = null;
  69
  70                 if ( $instance === null ) {
  71                         // NOTE: constructing GlobalVarConfig here is not particularly pretty,
  72                         // but some information from the global scope has to be injected here,
  73                         // even if it's just a file name or database credentials to load
  74                         // configuration from.
  75                         $config = new GlobalVarConfig();
  76                         $instance = new self( $config );
  77
  78                         // Load the default wiring from the specified files.
  79                         $wiringFiles = $config->get( 'ServiceWiringFiles' );
  80                         $instance->loadWiringFiles( $wiringFiles );
  81
  82                         // Provide a traditional hook point to allow extensions to configure services.
  83                         Hooks::run( 'MediaWikiServices', [ $instance ] );
  84                 }
  85
  86                 return $instance;
  87         }
  88
  89         /**
  90          * @param Config $config The Config object to be registered as the 'BootstrapConfig' service.
  91          *        This has to contain at least the information needed to set up the 'ConfigFactory'
  92          *        service.
  93          */
  94         public function __construct( Config $config ) {
  95                 parent::__construct();
  96
  97                 // register the given Config object as the bootstrap config service.
  98                 $this->defineService( 'BootstrapConfig', function() use ( $config ) {
  99                         return $config;
 100                 } );
 101         }
 102
 103         /**
 104          * Returns the Config object containing the bootstrap configuration.
 105          * Bootstrap configuration would typically include database credentials
 106          * and other information that may be needed before the ConfigFactory
 107          * service can be instantiated.
 108          *
 109          * @note This should only be used during bootstrapping, in particular
 110          * when creating the MainConfig service. Application logic should
 111          * use getMainConfig() to get a Config instances.
 112          *
 113          * @return Config
 114          */
 115         public function getBootstrapConfig() {
 116                 return $this->getService( 'BootstrapConfig' );
 117         }
 118
 119         /**
 120          * @return ConfigFactory
 121          */
 122         public function getConfigFactory() {
 123                 return $this->getService( 'ConfigFactory' );
 124         }
 125
 126         /**
 127          * Returns the Config object that provides configuration for MediaWiki core.
 128          * This may or may not be the same object that is returned by getBootstrapConfig().
 129          *
 130          * @return Config
 131          */
 132         public function getMainConfig() {
 133                 return $this->getService( 'MainConfig' );
 134         }
 135
 136         /**
 137          * @return SiteLookup
 138          */
 139         public function getSiteLookup() {
 140                 return $this->getService( 'SiteLookup' );
 141         }
 142
 143         /**
 144          * @return SiteStore
 145          */
 146         public function getSiteStore() {
 147                 return $this->getService( 'SiteStore' );
 148         }
 149
 150         /**
 151          * @return StatsdDataFactory
 152          */
 153         public function getStatsdDataFactory() {
 154                 return $this->getService( 'StatsdDataFactory' );
 155         }
 156
 157         /**
 158          * @return EventRelayerGroup
 159          */
 160         public function getEventRelayerGroup() {
 161                 return $this->getService( 'EventRelayerGroup' );
 162         }
 163
 164         /**
 165          * @return SearchEngine
 166          */
 167         public function newSearchEngine() {
 168                 // New engine object every time, since they keep state
 169                 return $this->getService( 'SearchEngineFactory' )->create();
 170         }
 171
 172         /**
 173          * @return SearchEngineFactory
 174          */
 175         public function getSearchEngineFactory() {
 176                 return $this->getService( 'SearchEngineFactory' );
 177         }
 178
 179         /**
 180          * @return SearchEngineConfig
 181          */
 182         public function getSearchEngineConfig() {
 183                 return $this->getService( 'SearchEngineConfig' );
 184         }
 185
 186         /**
 187          * @return SkinFactory
 188          */
 189         public function getSkinFactory() {
 190                 return $this->getService( 'SkinFactory' );
 191         }
 192
 193         ///////////////////////////////////////////////////////////////////////////
 194         // NOTE: When adding a service getter here, don't forget to add a test
 195         // case for it in MediaWikiServicesTest::provideGetters() and in
 196         // MediaWikiServicesTest::provideGetService()!
 197         ///////////////////////////////////////////////////////////////////////////
 198
 199 }