Fixes #2932: Added `yii\web\ViewAction` that allow you to render views based on GET parameter

framework/CHANGELOG.md

@@ -276,6 +276,7 @@ _ Chg #2912: Relative view files will be looked for under the directory containi
 - New #1956: Implemented test fixture framework (qiangxue)
 - New #2149: Added `yii\base\DynamicModel` to support ad-hoc data validation (qiangxue)
 - New #2360: Added `AttributeBehavior` and `BlameableBehavior`, and renamed `AutoTimestamp` to `TimestampBehavior` (lucianobaraglia, qiangxue)
+- New #2932: Added `yii\web\ViewAction` that allow you to render views based on GET parameter (samdark)
 - New: Yii framework now comes with core messages in multiple languages
 - New: Added `yii\codeception\DbTestCase` (qiangxue)
 - New: Added `yii\web\PrefixUrlRule` (qiangxue)

framework/web/ViewAction.php

+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\web;
+
+use yii\base\Action;
+use yii\base\InvalidParamException;
+
+/**
+ * ViewAction represents an action that displays a view according to a user-specified parameter.
+ *
+ * By default, the view being displayed is specified via the `view` GET parameter.
+ * The name of the GET parameter can be customized via [[\yii\base\ViewAction::$viewParam]].
+ * If the user doesn't provide the GET parameter, the default view specified by [[\yii\base\ViewAction::$defaultView]]
+ * will be displayed.
+ *
+ * Users specify a view in the format of `path/to/view`, which translates to the view name
+ * `BasePath/path/to/view` where `BasePath` is given by [[\yii\base\ViewAction::$basePath]].
+ *
+ * Note, the user specified view can only contain word characters, dots and dashes and
+ * the first letter must be a word letter.
+ *
+ * @property string $requestedView The name of the view requested by the user.
+ * This is in the format of 'path/to/view'.
+ *
+ * @author Alexander Makarov <sam@rmcreative.ru>
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @since 2.0
+ */
+class ViewAction extends Action
+{
+    /**
+     * @var string the name of the GET parameter that contains the requested view name. Defaults to 'view'.
+     */
+    public $viewParam = 'view';
+
+    /**
+     * @var string the name of the default view when [[\yii\base\ViewAction::$viewParam]] GET parameter is not provided
+     * by user. Defaults to 'index'. This should be in the format of 'path/to/view', similar to that given in
+     * the GET parameter.
+     * @see \yii\base\ViewAction::$basePath
+     */
+    public $defaultView = 'index';
+
+    /**
+     * @var string the base path for the views. Defaults to 'pages'.
+     * The base path will be prefixed to any user-specified page view.
+     * For example, if a user requests for `tutorial/chap1`, the corresponding view name will
+     * be `pages/tutorial/chap1`, assuming the base path is `pages`.
+     * The actual view file is determined by [[\yii\base\View::getViewFile()]].
+     * @see \yii\base\View::getViewFile()
+     */
+    public $basePath = 'pages';
+
+    /**
+     * @var mixed the name of the layout to be applied to the views.
+     * This will be assigned to [[\yii\base\Controller::$layout]] before the view is rendered.
+     * Defaults to null, meaning the controller's layout will be used.
+     * If false, no layout will be applied.
+     */
+    public $layout;
+
+    /**
+     * @var string Used to store controller layout during executin and then restore it
+     */
+    private $_controllerLayout;
+
+    /**
+     * Runs the action.
+     * This method displays the view requested by the user.
+     * @throws NotFoundHttpException if the view file cannot be found
+     */
+    public function run()
+    {
+        $viewPath = $this->getViewPath();
+
+        if($this->layout !== null) {
+            $this->_controllerLayout = $this->controller->layout;
+            $this->controller->layout = $this->layout;
+        }
+
+        try {
+            return $this->controller->render($viewPath);
+        } catch (InvalidParamException $e) {
+            if (YII_DEBUG) {
+                throw new NotFoundHttpException($e->getMessage());
+            } else {
+                throw new NotFoundHttpException(
+                    \Yii::t('yii', 'The requested view "{name}" was not found.', ['name' => $viewPath])
+                );
+            }
+        }
+    }
+
+    /**
+     * @inheritdoc
+     */
+    protected function afterRun()
+    {
+        if ($this->layout !== null) {
+            $this->controller->layout = $this->_controllerLayout;
+        }
+        parent::afterRun();
+    }
+
+    /**
+     * Obtain view path from GET
+     *
+     * @return string view path
+     * @throws NotFoundHttpException if view path doesn't match allowed format
+     */
+    protected function getViewPath()
+    {
+        $viewPath = \Yii::$app->request->get($this->viewParam);
+        if (empty($viewPath) || !is_string($viewPath)) {
+            $viewPath = $this->defaultView;
+        }
+
+        if (!preg_match('/^\w[\w\/\-]*$/', $viewPath)) {
+            if (YII_DEBUG) {
+                throw new NotFoundHttpException("The requested view \"$viewPath\" should start with a word char and contain word chars, forward slashes and dashes only.");
+            } else {
+                throw new NotFoundHttpException(\Yii::t('yii', 'The requested view "{name}" was not found.', ['name' => $viewPath]));
+            }
+        }
+
+        if (!empty($this->basePath)) {
+            $viewPath = $this->basePath . '/' . $viewPath;
+            return $viewPath;
+        }
+        return $viewPath;
+    }
+}
+ 
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