Added `yii\base\Controller::renderContent()`

docs/guide/structure-views.md

@@ -127,6 +127,8 @@ Within [controllers](structure-controllers.md), you may call the following contr
   and injects all registered JS/CSS scripts and files. It is usually used in response to AJAX Web requests.
 * [[yii\base\Controller::renderFile()|renderFile()]]: renders a view specified in terms of a view file path or
   [alias](concept-aliases.md).
+* [[yii\base\Controller::renderContent()|renderContent()]]: renders a static string by embedding it into
+  the currently applicable [layout](#layouts). This method is available since version 2.0.1.
 
 For example,
 

framework/CHANGELOG.md

@@ -52,6 +52,7 @@ Yii Framework 2 Change Log
 - Enh #5983: Added `Inflector::sentence()` (pana1990, qiangxue)
 - Enh: `Console::confirm()` now uses `Console::stdout()` instead of `echo` to be consistent with all other functions (cebe)
 - Enh: `yii\rbac\DbManager` migration now uses database component specified in component settings instead of always using default `db` (samdark)
+- Enh: Added `yii\base\Controller::renderContent()` (qiangxue)
 - Chg #3630: `yii\db\Command::queryInternal()` is now protected (samdark) 
 - Chg #5508: Dropped the support for the `--append` option for the `fixture` command (qiangxue)
 - Chg #5874: Upgraded Twitter Bootstrap to 3.3.x (samdark)

framework/base/Controller.php

@@ -364,17 +364,29 @@ class Controller extends Component implements ViewContextInterface
      */
     public function render($view, $params = [])
     {
-        $output = $this->getView()->render($view, $params, $this);
+        $content = $this->getView()->render($view, $params, $this);
+        return $this->renderContent($content);
+    }
+
+    /**
+     * Renders a static string by applying a layout.
+     * @param string $content the static string being rendered
+     * @return string the rendering result of the layout with the given static string as the `$content` variable.
+     * If the layout is disabled, the string will be returned back.
+     * @since 2.0.1
+     */
+    public function renderContent($content)
+    {
         $layoutFile = $this->findLayoutFile($this->getView());
         if ($layoutFile !== false) {
-            return $this->getView()->renderFile($layoutFile, ['content' => $output], $this);
+            return $this->getView()->renderFile($layoutFile, ['content' => $content], $this);
         } else {
-            return $output;
+            return $content;
         }
     }
 
     /**
-     * Renders a view.
+     * Renders a view without applying layout.
      * This method differs from [[render()]] in that it does not apply any layout.
      * @param string $view the view name. Please refer to [[render()]] on how to specify a view name.
      * @param array $params the parameters (name-value pairs) that should be made available in the view.