**Course Title:** Mastering Yii Framework: Building Scalable Web Applications **Section Title:** Routing, Controllers, and Views **Topic:** Creating and managing controllers In this topic, we will delve into the world of controllers in Yii, exploring how to create and manage them effectively. Controllers are a crucial part of the MVC architecture, acting as the intermediary between the model and view layers. They handle user input, interact with the model, and render the view. ### What are Controllers? Controllers are PHP classes that handle HTTP requests and responses. They are responsible for: 1. Handling user input (e.g., form submissions) 2. Interacting with the model to retrieve or update data 3. Rendering the view to display the result ### Creating a Controller To create a controller in Yii, follow these steps: 1. Open the `controllers` directory in your Yii project. 2. Create a new PHP file with a name that follows the convention `ControllerNameController.php`. 3. Define a class that extends `yii\base\Controller`. Here's an example of a simple controller: ```php // controllers/ExampleController.php namespace app\controllers; use yii\web\Controller; class ExampleController extends Controller { public function actionIndex() { return $this->render('index'); } } ``` ### Action Methods Action methods are the methods within a controller that handle specific HTTP requests. They are typically named in the format `actionVerb` (e.g., `actionIndex`, `actionCreate`, `actionUpdate`). Action methods can return one of the following: * A string representing the view to render * An array of data to be passed to the view * A redirect response ### Managing Controllers Here are some key concepts to keep in mind when managing controllers: * **Namespace**: Controllers should be placed in a namespace that follows the convention `app\controllers`. * **Class Name**: Controller classes should follow the convention `ControllerNameController`. * **Action Methods**: Action methods should be named in the format `actionVerb`. * **View Rendering**: Controllers can render views using the `render()` method. ### Best Practices Here are some best practices to keep in mind when creating and managing controllers: * **Keep Controllers Thin**: Controllers should be thin and focused on handling HTTP requests and responses. Avoid complex logic and business logic within controllers. * **Use Dependency Injection**: Controllers should use dependency injection to inject dependencies rather than creating them within the controller. * **Follow the Convention**: Follow the convention for naming controllers and action methods. ### Conclusion In this topic, we covered the basics of creating and managing controllers in Yii. We explored how to create a controller, define action methods, and manage controllers effectively. We also discussed best practices for creating and managing controllers. ### What's Next? In the next topic, we will explore building views with Yii's templating system (PHP-based). ### Leave a Comment or Ask for Help If you have any questions or need help with creating and managing controllers, please leave a comment below. ### External Resources * [Yii Framework Documentation: Controllers](https://www.yiiframework.com/doc/guide/2.0/en/structure-controllers) * [Yii Framework Documentation: Action Methods](https://www.yiiframework.com/doc/guide/2.0/en/structure-controllers#action-methods)