**Course Title:** Mastering Yii Framework: Building Scalable Web Applications **Section Title:** Routing, Controllers, and Views **Topic:** Introduction to routing in Yii (URL management) **Introduction** In the Yii framework, routing plays a crucial role in mapping URLs to controllers and actions. In this topic, we'll delve into the world of routing in Yii, exploring how it works, and how you can configure it to suit your application's needs. By the end of this section, you'll have a solid understanding of URL management in Yii and be able to create custom routes for your web applications. **What is Routing?** Routing is the process of mapping a URL to a specific controller action in your web application. In Yii, routing is handled by the `UrlManager` component, which is responsible for parsing URLs and determining which controller action should be executed. **Understanding URL Formats** In Yii, there are three types of URL formats: 1. **Absolute URL**: A complete URL that includes the protocol (http or https), domain, and path. Example: `http://localhost/yii-application/index.php?r=site/index` 2. **Relative URL**: A URL that is relative to the current domain. Example: `/index.php?r=site/index` 3. **Pretty URL**: A URL that is rewritten to look more user-friendly. Example: `/site/index` **Configuring Routing in Yii** To configure routing in Yii, you'll need to modify the `urlManager` component in the `config/web.php` file. Here's an example configuration: ```php 'components' => [ 'urlManager' => [ 'enablePrettyUrl' => true, 'enableStrictParsing' => true, 'showScriptName' => false, 'rules' => [ '' => 'site/index', '<_c:[\w\-]+>' => '<_c>/index', '<_c:[\w\-]+>/<id:\d+>' => '<_c>/view', '<_c:[\w\-]+>/<id:\d+>/<_a>' => '<_c>/<id>/<a>', ], ], ], ``` In this configuration: * `enablePrettyUrl` is set to `true`, which enables pretty URL support. * `enableStrictParsing` is set to `true`, which enables strict URL parsing. * `showScriptName` is set to `false`, which hides the script name in the URL. * The `rules` array defines the routing rules for the application. **Routing Rules** Routing rules are used to map URLs to controllers and actions. In Yii, routing rules are defined in the `rules` array of the `urlManager` component. Here's an example routing rule: ```php '<_c:[\w\-]+>/<id:\d+>' => '<_c>/view', ``` In this rule: * `<_c:[\w\-]+>` matches a controller name (e.g., `site`, `user`, etc.). * `<id:\d+>` matches a numeric ID (e.g., `123`, `456`, etc.). * `<_c>/view` is the route to the `view` action of the matching controller. **Using Route Parameters** Route parameters are used to pass values from the URL to the controller action. In Yii, route parameters are defined using the `<_p>` syntax. Here's an example of using route parameters: ```php '<_c:[\w\-]+>/<id:\d+>/<title:[\w\-]+>' => '<_c>/view', ``` In this rule: * `<id:\d+>` matches a numeric ID. * `<title:[\w\-]+>` matches a title string. * `<_c>/view` is the route to the `view` action of the matching controller. **Best Practices** Here are some best practices to keep in mind when configuring routing in Yii: * Use pretty URLs to create user-friendly URLs. * Use strict URL parsing to prevent security vulnerabilities. * Define routing rules carefully to avoid conflicts. * Use route parameters to pass values from the URL to the controller action. **Conclusion** In this topic, we've covered the basics of routing in Yii, including URL formats, configuring the `urlManager` component, and defining routing rules. We've also discussed best practices to keep in mind when working with routing in Yii. By following these guidelines, you'll be able to create custom routes for your web applications and improve the overall user experience. **What's Next?** In the next topic, we'll cover creating and managing controllers in Yii. **Leave a Comment or Ask for Help** If you have any questions or need further clarification on any of the topics covered in this section, please leave a comment below. **External Resources** * [Yii Framework Documentation: Routing](https://www.yiiframework.com/doc/guide/2.0/en/runtime-routing) * [Yii Framework Documentation: URL Manager](https://www.yiiframework.com/doc/guide/2.0/en/runtime-url-manager)