Turn module and application into DI containers.

extensions/authclient/AuthAction.php

@@ -164,7 +164,7 @@ class AuthAction extends Action
         if (!empty($_GET[$this->clientIdGetParamName])) {
             $clientId = $_GET[$this->clientIdGetParamName];
             /** @var \yii\authclient\Collection $collection */
-            $collection = Yii::$app->getComponent($this->clientCollection);
+            $collection = Yii::$app->get($this->clientCollection);
             if (!$collection->hasClient($clientId)) {
                 throw new NotFoundHttpException("Unknown auth client '{$clientId}'");
             }

extensions/authclient/widgets/Choice.php

@@ -143,7 +143,7 @@ class Choice extends Widget
     protected function defaultClients()
     {
         /** @var $collection \yii\authclient\Collection */
-        $collection = Yii::$app->getComponent($this->clientCollection);
+        $collection = Yii::$app->get($this->clientCollection);
 
         return $collection->getClients();
     }

extensions/debug/panels/RequestPanel.php

@@ -86,7 +86,7 @@ class RequestPanel extends Panel
             $action = null;
         }
         /** @var \yii\web\Session $session */
-        $session = Yii::$app->getComponent('session', false);
+        $session = Yii::$app->get('session', [], false);
 
         return [
             'flashes' => $session ? $session->getAllFlashes() : [],

extensions/elasticsearch/ActiveRecord.php

@@ -59,7 +59,7 @@ class ActiveRecord extends BaseActiveRecord
      */
     public static function getDb()
     {
-        return \Yii::$app->getComponent('elasticsearch');
+        return \Yii::$app->get('elasticsearch');
     }
 
     /**

extensions/elasticsearch/DebugAction.php

@@ -55,7 +55,7 @@ class DebugAction extends Action
         $options = ['pretty' => true];
 
         /** @var Connection $db */
-        $db = \Yii::$app->getComponent($this->db);
+        $db = \Yii::$app->get($this->db);
         $time = microtime(true);
         switch ($method) {
             case 'GET': $result = $db->get($url, $options, $body, true); break;

extensions/elasticsearch/Query.php

@@ -115,7 +115,7 @@ class Query extends Component implements QueryInterface
     public function createCommand($db = null)
     {
         if ($db === null) {
-            $db = Yii::$app->getComponent('elasticsearch');
+            $db = Yii::$app->get('elasticsearch');
         }
 
         $commandConfig = $db->getQueryBuilder()->build($this);

extensions/gii/generators/model/Generator.php

@@ -439,7 +439,7 @@ class Generator extends \yii\gii\Generator
     {
         if (Yii::$app->hasComponent($this->db) === false) {
             $this->addError('db', 'There is no application component named "db".');
-        } elseif (!Yii::$app->getComponent($this->db) instanceof Connection) {
+        } elseif (!Yii::$app->get($this->db) instanceof Connection) {
             $this->addError('db', 'The "db" application component must be a DB connection instance.');
         }
     }

extensions/mongodb/ActiveRecord.php

@@ -29,7 +29,7 @@ abstract class ActiveRecord extends BaseActiveRecord
      */
     public static function getDb()
     {
-        return \Yii::$app->getComponent('mongodb');
+        return \Yii::$app->get('mongodb');
     }
 
     /**

extensions/mongodb/Cache.php

@@ -62,7 +62,7 @@ class Cache extends \yii\caching\Cache
     {
         parent::init();
         if (is_string($this->db)) {
-            $this->db = Yii::$app->getComponent($this->db);
+            $this->db = Yii::$app->get($this->db);
         }
         if (!$this->db instanceof Connection) {
             throw new InvalidConfigException($this->className() . "::db must be either a MongoDB connection instance or the application component ID of a MongoDB connection.");

extensions/mongodb/Query.php

@@ -62,7 +62,7 @@ class Query extends Component implements QueryInterface
     public function getCollection($db = null)
     {
         if ($db === null) {
-            $db = Yii::$app->getComponent('mongodb');
+            $db = Yii::$app->get('mongodb');
         }
 
         return $db->getCollection($this->from);

extensions/mongodb/Session.php

@@ -56,7 +56,7 @@ class Session extends \yii\web\Session
     public function init()
     {
         if (is_string($this->db)) {
-            $this->db = Yii::$app->getComponent($this->db);
+            $this->db = Yii::$app->get($this->db);
         }
         if (!$this->db instanceof Connection) {
             throw new InvalidConfigException($this->className() . "::db must be either a MongoDB connection instance or the application component ID of a MongoDB connection.");

extensions/mongodb/file/Query.php

@@ -31,7 +31,7 @@ class Query extends \yii\mongodb\Query
     public function getCollection($db = null)
     {
         if ($db === null) {
-            $db = Yii::$app->getComponent('mongodb');
+            $db = Yii::$app->get('mongodb');
         }
 
         return $db->getFileCollection($this->from);

extensions/redis/ActiveRecord.php

@@ -45,7 +45,7 @@ class ActiveRecord extends BaseActiveRecord
      */
     public static function getDb()
     {
-        return \Yii::$app->getComponent('redis');
+        return \Yii::$app->get('redis');
     }
 
     /**

extensions/redis/Cache.php

@@ -76,7 +76,7 @@ class Cache extends \yii\caching\Cache
     {
         parent::init();
         if (is_string($this->redis)) {
-            $this->redis = Yii::$app->getComponent($this->redis);
+            $this->redis = Yii::$app->get($this->redis);
         } elseif (is_array($this->redis)) {
             if (!isset($this->redis['class'])) {
                 $this->redis['class'] = Connection::className();

extensions/redis/Session.php

@@ -80,7 +80,7 @@ class Session extends \yii\web\Session
     public function init()
     {
         if (is_string($this->redis)) {
-            $this->redis = Yii::$app->getComponent($this->redis);
+            $this->redis = Yii::$app->get($this->redis);
         } elseif (is_array($this->redis)) {
             if (!isset($this->redis['class'])) {
                 $this->redis['class'] = Connection::className();

extensions/sphinx/ActiveRecord.php

@@ -62,7 +62,7 @@ abstract class ActiveRecord extends BaseActiveRecord
      */
     public static function getDb()
     {
-        return \Yii::$app->getComponent('sphinx');
+        return \Yii::$app->get('sphinx');
     }
 
     /**

extensions/sphinx/Query.php

@@ -155,7 +155,7 @@ class Query extends Component implements QueryInterface
      */
     protected function defaultConnection()
     {
-        return Yii::$app->getComponent('sphinx');
+        return Yii::$app->get('sphinx');
     }
 
     /**

extensions/sphinx/Schema.php

@@ -132,7 +132,7 @@ class Schema extends Object
 
         if ($db->enableSchemaCache && !in_array($name, $db->schemaCacheExclude, true)) {
             /** @var $cache Cache */
-            $cache = is_string($db->schemaCache) ? Yii::$app->getComponent($db->schemaCache) : $db->schemaCache;
+            $cache = is_string($db->schemaCache) ? Yii::$app->get($db->schemaCache) : $db->schemaCache;
             if ($cache instanceof Cache) {
                 $key = $this->getCacheKey($name);
                 if ($refresh || ($index = $cache->get($key)) === false) {
@@ -296,7 +296,7 @@ class Schema extends Object
     public function refresh()
     {
         /** @var $cache Cache */
-        $cache = is_string($this->db->schemaCache) ? Yii::$app->getComponent($this->db->schemaCache) : $this->db->schemaCache;
+        $cache = is_string($this->db->schemaCache) ? Yii::$app->get($this->db->schemaCache) : $this->db->schemaCache;
         if ($this->db->enableSchemaCache && $cache instanceof Cache) {
             GroupDependency::invalidate($cache, $this->getCacheGroup());
         }

framework/base/Application.php

@@ -160,7 +160,6 @@ abstract class Application extends Module
 
         $this->preInit($config);
         $this->registerErrorHandlers();
-        $this->registerCoreComponents();
 
         Component::__construct($config);
     }
@@ -206,6 +205,17 @@ abstract class Application extends Module
         } elseif (!ini_get('date.timezone')) {
             $this->setTimeZone('UTC');
         }
+
+        // merge core components with custom components
+        if (!empty($config['components'])) {
+            foreach ($this->coreComponents() as $id => $component) {
+                if (!isset($config['components'][$id])) {
+                    $config['components'][$id] = $component;
+                } elseif (!isset($config['components'][$id]['class'])) {
+                    $config['components'][$id]['class'] = $component['class'];
+                }
+            }
+        }
     }
 
     /**
@@ -248,7 +258,7 @@ abstract class Application extends Module
      */
     public function preloadComponents()
     {
-        $this->getComponent('log');
+        $this->get('log');
         parent::preloadComponents();
     }
 
@@ -400,7 +410,7 @@ abstract class Application extends Module
      */
     public function getDb()
     {
-        return $this->getComponent('db');
+        return $this->get('db');
     }
 
     /**
@@ -409,7 +419,7 @@ abstract class Application extends Module
      */
     public function getLog()
     {
-        return $this->getComponent('log');
+        return $this->get('log');
     }
 
     /**
@@ -418,7 +428,7 @@ abstract class Application extends Module
      */
     public function getErrorHandler()
     {
-        return $this->getComponent('errorHandler');
+        return $this->get('errorHandler');
     }
 
     /**
@@ -427,7 +437,7 @@ abstract class Application extends Module
      */
     public function getCache()
     {
-        return $this->getComponent('cache');
+        return $this->get('cache');
     }
 
     /**
@@ -436,7 +446,7 @@ abstract class Application extends Module
      */
     public function getFormatter()
     {
-        return $this->getComponent('formatter');
+        return $this->get('formatter');
     }
 
     /**
@@ -445,7 +455,7 @@ abstract class Application extends Module
      */
     public function getRequest()
     {
-        return $this->getComponent('request');
+        return $this->get('request');
     }
 
     /**
@@ -454,7 +464,7 @@ abstract class Application extends Module
      */
     public function getView()
     {
-        return $this->getComponent('view');
+        return $this->get('view');
     }
 
     /**
@@ -463,7 +473,7 @@ abstract class Application extends Module
      */
     public function getUrlManager()
     {
-        return $this->getComponent('urlManager');
+        return $this->get('urlManager');
     }
 
     /**
@@ -472,7 +482,7 @@ abstract class Application extends Module
      */
     public function getI18n()
     {
-        return $this->getComponent('i18n');
+        return $this->get('i18n');
     }
 
     /**
@@ -481,7 +491,7 @@ abstract class Application extends Module
      */
     public function getMail()
     {
-        return $this->getComponent('mail');
+        return $this->get('mail');
     }
 
     /**
@@ -490,16 +500,16 @@ abstract class Application extends Module
      */
     public function getAuthManager()
     {
-        return $this->getComponent('authManager');
+        return $this->get('authManager');
     }
 
     /**
-     * Registers the core application components.
-     * @see setComponents
+     * Returns the core application components.
+     * @see set
      */
-    public function registerCoreComponents()
+    public function coreComponents()
     {
-        $this->setComponents([
+        return [
             'log' => ['class' => 'yii\log\Logger'],
             'errorHandler' => ['class' => 'yii\base\ErrorHandler'],
             'formatter' => ['class' => 'yii\base\Formatter'],
@@ -507,7 +517,7 @@ abstract class Application extends Module
             'mail' => ['class' => 'yii\swiftmailer\Mailer'],
             'urlManager' => ['class' => 'yii\web\UrlManager'],
             'view' => ['class' => 'yii\web\View'],
-        ]);
+        ];
     }
 
     /**

framework/base/Module.php

@@ -8,6 +8,8 @@
 namespace yii\base;
 
 use Yii;
+use yii\di\ContainerInterface;
+use yii\di\ContainerTrait;
 
 /**
  * Module is the base class for module and application classes.
@@ -35,8 +37,10 @@ use Yii;
  * @author Qiang Xue <qiang.xue@gmail.com>
  * @since 2.0
  */
-class Module extends Component
+class Module extends Component implements ContainerInterface
 {
+    use ContainerTrait;
+
     /**
      * @var array custom module parameters (name => value).
      */
@@ -110,10 +114,7 @@ class Module extends Component
      * @var array child modules of this module
      */
     private $_modules = [];
-    /**
-     * @var array components registered under this module
-     */
-    private $_components = [];
+
 
     /**
      * Constructor.
@@ -130,15 +131,14 @@ class Module extends Component
 
     /**
      * Getter magic method.
-     * This method is overridden to support accessing components
-     * like reading module properties.
+     * This method is overridden to support accessing components like reading properties.
      * @param  string $name component or property name
      * @return mixed  the named property value
      */
     public function __get($name)
     {
-        if ($this->hasComponent($name)) {
-            return $this->getComponent($name);
+        if ($this->has($name)) {
+            return $this->get($name);
         } else {
             return parent::__get($name);
         }
@@ -146,15 +146,14 @@ class Module extends Component
 
     /**
      * Checks if a property value is null.
-     * This method overrides the parent implementation by checking
-     * if the named component is loaded.
+     * This method overrides the parent implementation by checking if the named component is loaded.
      * @param  string  $name the property name or the event name
      * @return boolean whether the property value is null
      */
     public function __isset($name)
     {
-        if ($this->hasComponent($name)) {
-            return $this->getComponent($name) !== null;
+        if ($this->has($name)) {
+            return $this->get($name, [], false) !== null;
         } else {
             return parent::__isset($name);
         }
@@ -432,126 +431,14 @@ class Module extends Component
     }
 
     /**
-     * Checks whether the named component exists.
-     * @param  string  $id component ID
-     * @return boolean whether the named component exists. Both loaded and unloaded components
-     *                    are considered.
-     */
-    public function hasComponent($id)
-    {
-        return isset($this->_components[$id]);
-    }
-
-    /**
-     * Retrieves the named component.
-     * @param  string         $id   component ID (case-sensitive)
-     * @param  boolean        $load whether to load the component if it is not yet loaded.
-     * @return Component|null the component instance, null if the component does not exist.
-     * @see hasComponent()
-     */
-    public function getComponent($id, $load = true)
-    {
-        if (isset($this->_components[$id])) {
-            if ($this->_components[$id] instanceof Object) {
-                return $this->_components[$id];
-            } elseif ($load) {
-                return $this->_components[$id] = Yii::createObject($this->_components[$id]);
-            }
-        }
-
-        return null;
-    }
-
-    /**
-     * Registers a component with this module.
-     * @param string               $id        component ID
-     * @param Component|array|null $component the component to be registered with the module. This can
-     *                                        be one of the followings:
-     *
-     * - a [[Component]] object
-     * - a configuration array: when [[getComponent()]] is called initially for this component, the array
-     *   will be used to instantiate the component via [[Yii::createObject()]].
-     * - null: the named component will be removed from the module
-     */
-    public function setComponent($id, $component)
-    {
-        if ($component === null) {
-            unset($this->_components[$id]);
-        } else {
-            $this->_components[$id] = $component;
-        }
-    }
-
-    /**
-     * Returns the registered components.
-     * @param  boolean $loadedOnly whether to return the loaded components only. If this is set false,
-     *                             then all components specified in the configuration will be returned, whether they are loaded or not.
-     *                             Loaded components will be returned as objects, while unloaded components as configuration arrays.
-     * @return array   the components (indexed by their IDs)
-     */
-    public function getComponents($loadedOnly = false)
-    {
-        if ($loadedOnly) {
-            $components = [];
-            foreach ($this->_components as $component) {
-                if ($component instanceof Component) {
-                    $components[] = $component;
-                }
-            }
-
-            return $components;
-        } else {
-            return $this->_components;
-        }
-    }
-
-    /**
-     * Registers a set of components in this module.
-     *
-     * Each component should be specified as a name-value pair, where
-     * name refers to the ID of the component and value the component or a configuration
-     * array that can be used to create the component. In the latter case, [[Yii::createObject()]]
-     * will be used to create the component.
-     *
-     * If a new component has the same ID as an existing one, the existing one will be overwritten silently.
-     *
-     * The following is an example for setting two components:
-     *
-     * ~~~
-     * [
-     *     'db' => [
-     *         'class' => 'yii\db\Connection',
-     *         'dsn' => 'sqlite:path/to/file.db',
-     *     ],
-     *     'cache' => [
-     *         'class' => 'yii\caching\DbCache',
-     *         'db' => 'db',
-     *     ],
-     * ]
-     * ~~~
-     *
-     * @param array $components components (id => component configuration or instance)
-     */
-    public function setComponents($components)
-    {
-        foreach ($components as $id => $component) {
-            if (!is_object($component) && isset($this->_components[$id]['class']) && !isset($component['class'])) {
-                // set default component class
-                $component['class'] = $this->_components[$id]['class'];
-            }
-            $this->_components[$id] = $component;
-        }
-    }
-
-    /**
      * Loads components that are declared in [[preload]].
      * @throws InvalidConfigException if a component or module to be preloaded is unknown
      */
     public function preloadComponents()
     {
         foreach ($this->preload as $id) {
-            if ($this->hasComponent($id)) {
-                $this->getComponent($id);
+            if ($this->has($id)) {
+                $this->get($id);
             } elseif ($this->hasModule($id)) {
                 $this->getModule($id);
             } else {

framework/caching/DbCache.php

@@ -80,7 +80,7 @@ class DbCache extends Cache
     {
         parent::init();
         if (is_string($this->db)) {
-            $this->db = Yii::$app->getComponent($this->db);
+            $this->db = Yii::$app->get($this->db);
         }
         if (!$this->db instanceof Connection) {
             throw new InvalidConfigException("DbCache::db must be either a DB connection instance or the application component ID of a DB connection.");

framework/caching/DbDependency.php

@@ -45,7 +45,7 @@ class DbDependency extends Dependency
      */
     protected function generateDependencyData($cache)
     {
-        $db = Yii::$app->getComponent($this->db);
+        $db = Yii::$app->get($this->db);
         if (!$db instanceof Connection) {
             throw new InvalidConfigException("DbDependency::db must be the application component ID of a DB connection.");
         }

framework/console/Application.php

@@ -154,7 +154,7 @@ class Application extends \yii\base\Application
      */
     public function getResponse()
     {
-        return $this->getComponent('response');
+        return $this->get('response');
     }
 
     /**
@@ -193,15 +193,13 @@ class Application extends \yii\base\Application
     }
 
     /**
-     * Registers the core application components.
-     * @see setComponents
+     * @inheritdoc
      */
-    public function registerCoreComponents()
+    public function coreComponents()
     {
-        parent::registerCoreComponents();
-        $this->setComponents([
+        return array_merge([
             'request' => ['class' => 'yii\console\Request'],
             'response' => ['class' => 'yii\console\Response'],
-        ]);
+        ], parent::coreComponents());
     }
 }

framework/console/controllers/CacheController.php

@@ -26,7 +26,7 @@ class CacheController extends Controller
     public function actionIndex()
     {
         $caches = [];
-        $components = Yii::$app->getComponents();
+        $components = Yii::$app->getComponentDefinitions();
         foreach ($components as $name => $component) {
             if ($component instanceof Cache) {
                 $caches[$name] = get_class($component);
@@ -53,7 +53,7 @@ class CacheController extends Controller
     public function actionFlush($component = 'cache')
     {
         /** @var Cache $cache */
-        $cache = Yii::$app->getComponent($component);
+        $cache = Yii::$app->get($component);
         if (!$cache || !$cache instanceof Cache) {
             throw new Exception('Application component "'.$component.'" is not defined or not a cache.');
         }

framework/console/controllers/MessageController.php

@@ -129,7 +129,7 @@ class MessageController extends Controller
                 }
             }
         } elseif ($config['format'] === 'db') {
-            $db = \Yii::$app->getComponent(isset($config['db']) ? $config['db'] : 'db');
+            $db = \Yii::$app->get(isset($config['db']) ? $config['db'] : 'db');
             if (!$db instanceof \yii\db\Connection) {
                 throw new Exception('The "db" option must refer to a valid database application component.');
             }

framework/console/controllers/MigrateController.php

@@ -122,7 +122,7 @@ class MigrateController extends Controller
 
             if ($action->id !== 'create') {
                 if (is_string($this->db)) {
-                    $this->db = Yii::$app->getComponent($this->db);
+                    $this->db = Yii::$app->get($this->db);
                 }
                 if (!$this->db instanceof Connection) {
                     throw new Exception("The 'db' option must refer to the application component ID of a DB connection.");

framework/data/ActiveDataProvider.php

@@ -85,7 +85,7 @@ class ActiveDataProvider extends BaseDataProvider
     {
         parent::init();
         if (is_string($this->db)) {
-            $this->db = Yii::$app->getComponent($this->db);
+            $this->db = Yii::$app->get($this->db);
             if ($this->db === null) {
                 throw new InvalidConfigException('The "db" property must be a valid DB Connection application component.');
             }

framework/data/SqlDataProvider.php

@@ -90,7 +90,7 @@ class SqlDataProvider extends BaseDataProvider
     {
         parent::init();
         if (is_string($this->db)) {
-            $this->db = Yii::$app->getComponent($this->db);
+            $this->db = Yii::$app->get($this->db);
         }
         if (!$this->db instanceof Connection) {
             throw new InvalidConfigException('The "db" property must be a valid DB Connection application component.');

framework/db/Command.php

@@ -378,7 +378,7 @@ class Command extends \yii\base\Component
 
         /** @var \yii\caching\Cache $cache */
         if ($db->enableQueryCache && $method !== '') {
-            $cache = is_string($db->queryCache) ? Yii::$app->getComponent($db->queryCache) : $db->queryCache;
+            $cache = is_string($db->queryCache) ? Yii::$app->get($db->queryCache) : $db->queryCache;
         }
 
         if (isset($cache) && $cache instanceof Cache) {

framework/db/Migration.php

@@ -49,7 +49,7 @@ class Migration extends \yii\base\Component
     {
         parent::init();
         if ($this->db === null) {
-            $this->db = \Yii::$app->getComponent('db');
+            $this->db = \Yii::$app->get('db');
         }
     }
 

framework/db/Schema.php

@@ -96,7 +96,7 @@ abstract class Schema extends Object
 
         if ($db->enableSchemaCache && !in_array($name, $db->schemaCacheExclude, true)) {
             /** @var Cache $cache */
-            $cache = is_string($db->schemaCache) ? Yii::$app->getComponent($db->schemaCache) : $db->schemaCache;
+            $cache = is_string($db->schemaCache) ? Yii::$app->get($db->schemaCache) : $db->schemaCache;
             if ($cache instanceof Cache) {
                 $key = $this->getCacheKey($name);
                 if ($refresh || ($table = $cache->get($key)) === false) {
@@ -225,7 +225,7 @@ abstract class Schema extends Object
     public function refresh()
     {
         /** @var Cache $cache */
-        $cache = is_string($this->db->schemaCache) ? Yii::$app->getComponent($this->db->schemaCache) : $this->db->schemaCache;
+        $cache = is_string($this->db->schemaCache) ? Yii::$app->get($this->db->schemaCache) : $this->db->schemaCache;
         if ($this->db->enableSchemaCache && $cache instanceof Cache) {
             GroupDependency::invalidate($cache, $this->getCacheGroup());
         }

framework/di/ContainerTrait.php

@@ -191,7 +191,7 @@ trait ContainerTrait
                 $definition['class'] = $typeOrID;
                 $this->_definitions[$typeOrID] = $definition;
             } else {
-                throw new InvalidConfigException("The configuration for \"$typeOrID\" must contain a \"class\" element.");
+                throw new InvalidConfigException("The configuration for the \"$typeOrID\" component must contain a \"class\" element.");
             }
         } else {
             // a type or ID

framework/i18n/DbMessageSource.php

@@ -94,14 +94,14 @@ class DbMessageSource extends MessageSource
     {
         parent::init();
         if (is_string($this->db)) {
-            $this->db = Yii::$app->getComponent($this->db);
+            $this->db = Yii::$app->get($this->db);
         }
         if (!$this->db instanceof Connection) {
             throw new InvalidConfigException("DbMessageSource::db must be either a DB connection instance or the application component ID of a DB connection.");
         }
         if ($this->enableCaching) {
             if (is_string($this->cache)) {
-                $this->cache = Yii::$app->getComponent($this->cache);
+                $this->cache = Yii::$app->get($this->cache);
             }
             if (!$this->cache instanceof Cache) {
                 throw new InvalidConfigException("DbMessageSource::cache must be either a cache object or the application component ID of the cache object.");

framework/log/DbTarget.php

@@ -63,7 +63,7 @@ class DbTarget extends Target
     {
         parent::init();
         if (is_string($this->db)) {
-            $this->db = Yii::$app->getComponent($this->db);
+            $this->db = Yii::$app->get($this->db);
         }
         if (!$this->db instanceof Connection) {
             throw new InvalidConfigException("DbTarget::db must be either a DB connection instance or the application component ID of a DB connection.");

framework/log/EmailTarget.php

@@ -44,7 +44,7 @@ class EmailTarget extends Target
             throw new InvalidConfigException('The "to" option must be set for EmailTarget::message.');
         }
         if (is_string($this->mail)) {
-            $this->mail = Yii::$app->getComponent($this->mail);
+            $this->mail = Yii::$app->get($this->mail);
         }
         if (!$this->mail instanceof MailerInterface) {
             throw new InvalidConfigException("EmailTarget::mailer must be either a mailer object or the application component ID of a mailer object.");

framework/log/Target.php

@@ -247,10 +247,10 @@ abstract class Target extends Component
         $request = Yii::$app->getRequest();
         $ip = $request instanceof Request ? $request->getUserIP() : '-';
         /** @var \yii\web\User $user */
-        $user = Yii::$app->getComponent('user', false);
+        $user = Yii::$app->get('user', [], false);
         $userID = $user ? $user->getId(false) : '-';
         /** @var \yii\web\Session $session */
-        $session = Yii::$app->getComponent('session', false);
+        $session = Yii::$app->get('session', [], false);
         $sessionID = $session && $session->getIsActive() ? $session->getId() : '-';
         return "[$ip] [$userID] [$sessionID]";
     }

framework/mutex/DbMutex.php

@@ -32,7 +32,7 @@ abstract class DbMutex extends Mutex
     {
         parent::init();
         if (is_string($this->db)) {
-            $this->db = Yii::$app->getComponent($this->db);
+            $this->db = Yii::$app->get($this->db);
         }
         if (!$this->db instanceof Connection) {
             throw new InvalidConfigException('Mutex::db must be either a DB connection instance or the application component ID of a DB connection.');

framework/rbac/DbManager.php

@@ -60,7 +60,7 @@ class DbManager extends Manager
     public function init()
     {
         if (is_string($this->db)) {
-            $this->db = Yii::$app->getComponent($this->db);
+            $this->db = Yii::$app->get($this->db);
         }
         if (!$this->db instanceof Connection) {
             throw new InvalidConfigException("DbManager::db must be either a DB connection instance or the application component ID of a DB connection.");

framework/test/DbFixture.php

@@ -35,7 +35,7 @@ abstract class DbFixture extends Fixture
     {
         parent::init();
         if (is_string($this->db)) {
-            $this->db = Yii::$app->getComponent($this->db);
+            $this->db = Yii::$app->get($this->db);
         }
         if (!is_object($this->db)) {
             throw new InvalidConfigException("The 'db' property must be either a DB connection instance or the application component ID of a DB connection.");

framework/web/Application.php

@@ -129,7 +129,7 @@ class Application extends \yii\base\Application
      */
     public function getRequest()
     {
-        return $this->getComponent('request');
+        return $this->get('request');
     }
 
     /**
@@ -138,7 +138,7 @@ class Application extends \yii\base\Application
      */
     public function getResponse()
     {
-        return $this->getComponent('response');
+        return $this->get('response');
     }
 
     /**
@@ -147,7 +147,7 @@ class Application extends \yii\base\Application
      */
     public function getSession()
     {
-        return $this->getComponent('session');
+        return $this->get('session');
     }
 
     /**
@@ -156,7 +156,7 @@ class Application extends \yii\base\Application
      */
     public function getUser()
     {
-        return $this->getComponent('user');
+        return $this->get('user');
     }
 
     /**
@@ -165,22 +165,20 @@ class Application extends \yii\base\Application
      */
     public function getAssetManager()
     {
-        return $this->getComponent('assetManager');
+        return $this->get('assetManager');
     }
 
     /**
-     * Registers the core application components.
-     * @see setComponents
+     * @inheritdoc
      */
-    public function registerCoreComponents()
+    public function coreComponents()
     {
-        parent::registerCoreComponents();
-        $this->setComponents([
+        return array_merge([
             'request' => ['class' => 'yii\web\Request'],
             'response' => ['class' => 'yii\web\Response'],
             'session' => ['class' => 'yii\web\Session'],
             'user' => ['class' => 'yii\web\User'],
             'assetManager' => ['class' => 'yii\web\AssetManager'],
-        ]);
+        ], parent::coreComponents());
     }
 }

framework/web/CacheSession.php

@@ -53,7 +53,7 @@ class CacheSession extends Session
     public function init()
     {
         if (is_string($this->cache)) {
-            $this->cache = Yii::$app->getComponent($this->cache);
+            $this->cache = Yii::$app->get($this->cache);
         }
         if (!$this->cache instanceof Cache) {
             throw new InvalidConfigException('CacheSession::cache must refer to the application component ID of a cache object.');

framework/web/DbSession.php

@@ -75,7 +75,7 @@ class DbSession extends Session
     public function init()
     {
         if (is_string($this->db)) {
-            $this->db = Yii::$app->getComponent($this->db);
+            $this->db = Yii::$app->get($this->db);
         }
         if (!$this->db instanceof Connection) {
             throw new InvalidConfigException("DbSession::db must be either a DB connection instance or the application component ID of a DB connection.");

framework/web/UrlManager.php

@@ -145,7 +145,7 @@ class UrlManager extends Component
             return;
         }
         if (is_string($this->cache)) {
-            $this->cache = Yii::$app->getComponent($this->cache);
+            $this->cache = Yii::$app->get($this->cache);
         }
         if ($this->cache instanceof Cache) {
             $key = __CLASS__;

framework/widgets/FragmentCache.php

@@ -82,7 +82,7 @@ class FragmentCache extends Widget
         if (!$this->enabled) {
             $this->cache = null;
         } elseif (is_string($this->cache)) {
-            $this->cache = Yii::$app->getComponent($this->cache);
+            $this->cache = Yii::$app->get($this->cache);
         }
 
         if ($this->getCachedContent() === false) {

tests/unit/extensions/swiftmailer/MessageTest.php

@@ -68,7 +68,7 @@ class MessageTest extends VendorTestCase
      */
     protected function createTestMessage()
     {
-        return Yii::$app->getComponent('mail')->compose();
+        return Yii::$app->get('mail')->compose();
     }
 
     /**

tests/unit/framework/mail/BaseMailerTest.php

@@ -59,7 +59,7 @@ class BaseMailerTest extends TestCase
      */
     protected function getTestMailComponent()
     {
-        return Yii::$app->getComponent('mail');
+        return Yii::$app->get('mail');
     }
 
     // Tests :

tests/unit/framework/mail/BaseMessageTest.php

@@ -36,7 +36,7 @@ class BaseMessageTest extends TestCase
      */
     protected function getMailer()
     {
-        return Yii::$app->getComponent('mail');
+        return Yii::$app->get('mail');
     }
 
     // Tests :

tests/unit/framework/test/ActiveFixtureTest.php

@@ -58,7 +58,7 @@ class ActiveFixtureTest extends DatabaseTestCase
     public function setUp()
     {
         parent::setUp();
-        \Yii::$app->setComponent('db', $this->getConnection());
+        \Yii::$app->set('db', $this->getConnection());
         ActiveRecord::$db = $this->getConnection();
     }
 

tests/unit/framework/web/CacheSessionTest.php

@@ -15,7 +15,7 @@ class CacheSessionTest extends \yiiunit\TestCase
     {
         parent::setUp();
         $this->mockApplication();
-        Yii::$app->setComponent('cache', new FileCache());
+        Yii::$app->set('cache', new FileCache());
     }
 
     public function testCacheSession()