Fixes #3298: Supported configuring `View::theme` using a class name

framework/CHANGELOG.md

@@ -35,6 +35,7 @@ Yii Framework 2 Change Log
 - Enh #3222: Added `useTablePrefix` option to the model generator for Gii (horizons2)
 - Enh #3230: Added `yii\filters\AccessControl::user` to support access control with different actors (qiangxue)
 - Enh #3252: Added support for case insensitive matching using ILIKE to PostgreSQL QueryBuilder (cebe)
+- Enh #3298: Supported configuring `View::theme` using a class name (netyum, qiangxue)
 - Enh: Added support for using sub-queries when building a DB query with `IN` condition (qiangxue)
 - Enh: Supported adding a new response formatter without the need to reconfigure existing formatters (qiangxue)
 - Enh: Added `yii\web\UrlManager::addRules()` to simplify adding new URL rules (qiangxue)

framework/base/View.php

@@ -72,7 +72,7 @@ class View extends Component
      */
     public $defaultExtension = 'php';
     /**
-     * @var Theme|array the theme object or the configuration array for creating the theme object.
+     * @var Theme|array|string the theme object or the configuration for creating the theme object.
      * If not set, it means theming is not enabled.
      */
     public $theme;
@@ -114,6 +114,8 @@ class View extends Component
                 $this->theme['class'] = 'yii\base\Theme';
             }
             $this->theme = Yii::createObject($this->theme);
+        } elseif (is_string($this->theme)) {
+            $this->theme = Yii::createObject($this->theme);
         }
     }