includes/config/ConfigFactory.php

   1 <?php
   2
   3 /**
   4  * Copyright 2014
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  19  * http://www.gnu.org/copyleft/gpl.html
  20  *
  21  * @file
  22  */
  23
  24 /**
  25  * Factory class to create Config objects
  26  *
  27  * @since 1.23
  28  */
  29 class ConfigFactory {
  30
  31         /**
  32          * Map of config name => callback
  33          * @var array
  34          */
  35         protected $factoryFunctions = [];
  36
  37         /**
  38          * Config objects that have already been created
  39          * name => Config object
  40          * @var array
  41          */
  42         protected $configs = [];
  43
  44         /**
  45          * @deprecated since 1.27, use MediaWikiServices::getConfigFactory() instead.
  46          *
  47          * @return ConfigFactory
  48          */
  49         public static function getDefaultInstance() {
  50                 return \MediaWiki\MediaWikiServices::getInstance()->getConfigFactory();
  51         }
  52
  53         /**
  54          * @return string[]
  55          */
  56         public function getConfigNames() {
  57                 return array_keys( $this->factoryFunctions );
  58         }
  59
  60         /**
  61          * Register a new config factory function.
  62          * Will override if it's already registered.
  63          * Use "*" for $name to provide a fallback config for all unknown names.
  64          * @param string $name
  65          * @param callable|Config $callback A factory callabck that takes this ConfigFactory
  66          *        as an argument and returns a Config instance, or an existing Config instance.
  67          * @throws InvalidArgumentException If an invalid callback is provided
  68          */
  69         public function register( $name, $callback ) {
  70                 if ( $callback instanceof Config ) {
  71                         $instance = $callback;
  72
  73                         // Register a callback anyway, for consistency. Note that getConfigNames()
  74                         // relies on $factoryFunctions to have all config names.
  75                         $callback = function() use ( $instance ) {
  76                                 return $instance;
  77                         };
  78                 } else {
  79                         $instance = null;
  80                 }
  81
  82                 if ( !is_callable( $callback ) ) {
  83                         throw new InvalidArgumentException( 'Invalid callback provided' );
  84                 }
  85
  86                 $this->configs[$name] = $instance;
  87                 $this->factoryFunctions[$name] = $callback;
  88         }
  89
  90         /**
  91          * Create a given Config using the registered callback for $name.
  92          * If an object was already created, the same Config object is returned.
  93          * @param string $name Name of the extension/component you want a Config object for
  94          *                     'main' is used for core
  95          * @throws ConfigException If a factory function isn't registered for $name
  96          * @throws UnexpectedValueException If the factory function returns a non-Config object
  97          * @return Config
  98          */
  99         public function makeConfig( $name ) {
 100                 if ( !isset( $this->configs[$name] ) ) {
 101                         $key = $name;
 102                         if ( !isset( $this->factoryFunctions[$key] ) ) {
 103                                 $key = '*';
 104                         }
 105                         if ( !isset( $this->factoryFunctions[$key] ) ) {
 106                                 throw new ConfigException( "No registered builder available for $name." );
 107                         }
 108                         $conf = call_user_func( $this->factoryFunctions[$key], $this );
 109                         if ( $conf instanceof Config ) {
 110                                 $this->configs[$name] = $conf;
 111                         } else {
 112                                 throw new UnexpectedValueException( "The builder for $name returned a non-Config object." );
 113                         }
 114                 }
 115
 116                 return $this->configs[$name];
 117         }
 118
 119 }