How do I use CAPTCHA in Yii forms?

In Yii, the controller coordinates application logic by processing user requests, interactive models, and rendering views. The main responsibilities of the controller include: ① Processing HTTP requests; ② Interacting with the model to obtain or save data; ③ Deciding which view to display and pass data; ④ Processing form submissions; ⑤ Returning HTML, JSON or redirection responses. Yii controllers are usually inherited from yii\web\Controller, and each public method corresponds to an action that can be accessed through the URL. For example, visiting http://example.com/site/index will call the actionIndex() method of SiteController. Common tasks include verification of input, calling models, and rendering

The steps to create a new view in the Yii framework are as follows: 1. Store the view file in the corresponding subdirectory in the views directory according to the controller name, such as views/site/; 2. Create a .php file and use lowercase plus short horizontal lines to name it, such as view-detail.php, and embed the PHP variable display content; 3. Use the $this->render() method in the controller to call the view and pass the required variables; 4. Optionally use the layout file to unify the page structure, and achieve it by setting $this->layout or adding layout comments to the view; finally check whether the path, view call and variable transmission are correct.

Gii is a powerful code generation tool in the Yii framework, which accelerates the development process by generating boilerplate code based on database structure or input parameters. Specifically, Gii can generate ActiveRecord models, create controllers containing CRUD operations, build corresponding views, and help build components such as modules and forms. To enable Gii, add 'gii' to the 'bootstrap' array in the configuration file config/web.php, and configure its class and access restricted IP in the 'modules' section. Gii helps keep code consistency and conforms to Yii best practices and is suitable for quickly building data-intensive applications such as CMS or management panels. Although the generated code is a skeleton,

There are three ways to define database relationships in Yii: one-to-one, one-to-many and many-to-many. 1. Use the hasOne() method one-to-one, such as the User model obtains the corresponding Profile through getProfile(); 2. Use the hasMany() method one-to-many, such as the Customer model obtains all orders through getOrders(); 3. Use viaTable() for many to many, such as the User model obtains multiple roles through getRoles(), and use the intermediate table user_role to improve query efficiency and keep the code tidy.

In Yii, widgets are reusable components used to encapsulate common UI elements or logic. Its core role is to improve development efficiency and maintain interface consistency. Using Yii widgets can avoid repeated writing of code, realize code reuse, maintain unified interface, separate focus points, and facilitate expansion. Yii provides a variety of built-in widgets, such as ActiveForm for model forms, ListView/GridView display list and table data, Pagination implementation of pagination control, and Menu dynamically generate navigation menus. When view code is found to be duplicated, logical and presentation required, or abstract dynamic behavior, custom widgets should be created. The creation method is inherited by yii\base.Wid

Yii The key to preventing CSRF attacks is to use the built-in mechanism correctly. First, Yii enables CSRF protection by default and generates tokens automatically. Tokens will be added automatically when using ActiveForm or Html::beginForm; second, when writing forms manually or using AJAX, you need to obtain the token through Yii::$app->request->csrfToken, and it is recommended to pass it to JS through meta tags; third, for the API interface, you can choose to turn off CSRF and strengthen other authentications such as JWT, or pass tokens through header; finally, sensitive operations should be avoided in GET requests, and only use POST/PUT/

Ensuring the security of Yii applications requires starting from five aspects: input verification, authentication and authorization, database security, error handling and configuration management. 1. Input verification should use model rules to filter user input, such as required, email, string validators, and combine HtmlPurifier to prevent XSS attacks; 2. In terms of authentication, Yii's RBAC management permissions should be used to restrict access roles through AccessControl; 3. Database operations should rely on parameterized queries to prevent SQL injection and avoid hard-coded database credentials; 4. Error handling requires closing debug mode, setting custom error pages and recording logs; 5. Configuration management should regularly update the framework and dependency library to fix vulnerabilities

To become a master of Yii, you need to master the following skills: 1) Understand Yii's MVC architecture, 2) Proficient in using ActiveRecordORM, 3) Effectively utilize Gii code generation tools, 4) Master Yii's verification rules, 5) Optimize database query performance, 6) Continuously pay attention to Yii ecosystem and community resources. Through the learning and practice of these skills, the development capabilities under the Yii framework can be comprehensively improved.