Yii2 Laravel Package

Getting Started

Minimal Steps

1. Installation

   composer create-project --prefer-dist yiisoft/yii2-app-basic basic
   

   Navigate to the project directory and run:

   composer install
   

2. First Use Case: Basic CRUD

   • Scaffold a model, view, and controller using Gii (Yii’s built-in code generator):
     • Enable Gii in config/web.php:

       'enableGii' => true,
       

     • Access http://your-app.dev/gii and generate a CRUD for a model (e.g., Post).

3. Key Files to Review

   • config/web.php: Core application configuration (routes, middleware, components).
   • models/: Business logic and database interactions.
   • controllers/: HTTP request handling.
   • views/: Presentation layer (Twig or PHP templates).

Implementation Patterns

Core Workflows

1. MVC Integration

   • Model: Extend yii\base\Model or yii\db\ActiveRecord for database interactions.

     namespace app\models;
     use yii\db\ActiveRecord;
     
     class Post extends ActiveRecord { /* ... */ }
     

   • Controller: Use dependency injection for services/models.

     public function actionView($id) {
         $post = Post::findOne($id);
         return $this->render('view', ['post' => $post]);
     }
     

   • View: Leverage Yii’s widgets and helpers (e.g., GridView, Url::to()).

2. Database Operations

   • ActiveRecord: ORM for CRUD.

     $post = new Post();
     $post->title = 'Hello Yii';
     $post->save();
     

   • Query Builder: Complex queries.

     $posts = Post::find()->where(['status' => 1])->all();
     

3. Routing and URL Handling

   • Define routes in config/web.php:

     'urlManager' => [
         'enablePrettyUrl' => true,
         'showScriptName' => false,
         'rules' => [
             'posts/<id:\d+>' => 'post/view',
         ],
     ],
     

   • Use Url::to() in views/controllers for dynamic links.

4. Middleware and Filters

   • Apply behaviors to controllers:

     public function behaviors() {
         return [
             'access' => ['class' => \yii\filters\AccessControl::class],
         ];
     }
     

   • Use beforeAction for pre-processing:

     public function beforeAction($action) {
         if ($action->id === 'index' && !$this->user->isGuest) {
             return $this->redirect(['site/index']);
         }
         return parent::beforeAction($action);
     }
     

5. Asset Management

   • Bundle CSS/JS in AssetBundle:

     namespace app\assets;
     use yii\web\AssetBundle;
     
     class AppAsset extends AssetBundle {
         public $basePath = '@webroot';
         public $baseUrl = '@web';
         public $css = ['css/site.css'];
         public $js = ['js/site.js'];
     }
     

   • Register in layouts/views:

     AppAsset::register($this);
     

6. Authentication and Authorization

   • Use yii\web\User for sessions/auth:

     if (Yii::$app->user->isGuest) {
         return $this->goHome();
     }
     

   • RBAC via yii\rbac\PhpManager:

     $auth = Yii::$app->authManager;
     $auth->addRole('admin');
     $auth->addPermission('createPost');
     $auth->addChild('admin', 'createPost');
     

7. API Development

   • RESTful controllers with yii\rest\ActiveController:

     namespace app\controllers;
     use yii\rest\ActiveController;
     
     class PostController extends ActiveController {
         public $modelClass = 'app\models\Post';
     }
     

   • Enable in config/web.php:

     'components' => [
         'urlManager' => [
             'enablePrettyUrl' => true,
             'rules' => [
                 'api/v1/posts' => 'post/index',
             ],
         ],
     ],
     

Gotchas and Tips

Pitfalls

1. Case Sensitivity in Routes

   • Yii routes are case-sensitive by default. Use lowercaseUrl in UrlManager if needed:

     'urlManager' => [
         'lowercaseUrl' => true,
     ],
     

2. Session Configuration

   • Ensure session component is properly configured in config/web.php:

     'components' => [
         'session' => [
             'class' => 'yii\web\CookieSession',
             'timeout' => 120,
         ],
     ],
     

   • For custom storage (e.g., Redis), use:

     'session' => [
         'class' => 'yii\redis\Session',
         'timeout' => 120,
     ],
     

3. ActiveRecord Caching

   • Cache queries to avoid N+1 problems:

     Yii::$app->db->enableQueryCache = true;
     Yii::$app->cache = [
         'class' => 'yii\caching\FileCache',
     ];
     

4. Gii Security

   • Restrict Gii access in production by IP or user role:

     'modules' => [
         'gii' => [
             'class' => 'yii\gii\Module',
             'allowedIPs' => ['127.0.0.1', '::1'],
         ],
     ],
     

5. Event Handling

   • Override events carefully to avoid infinite loops:

     public function init() {
         parent::init();
         $this->on('eventName', function($event) {
             // Handle event
         });
     }
     

6. Translation Quirks

   • Ensure sourceLanguage and translations are set in i18n:

     'i18n' => [
         'sourceLanguage' => 'en-US',
         'translations' => [
             'app*' => [
                 'class' => 'yii\i18n\PhpMessageSource',
                 'basePath' => '@app/messages',
             ],
         ],
     ],
     

   • Use Yii::t() for translations:

     Yii::t('app', 'Hello {name}', ['name' => 'World']);
     

7. Asset Publishing

   • Publish assets before using them in views:

     Yii::$app->assetManager->publish($assetBundle);
     

   • Debug missing assets with:

     php yii asset/index
     

Debugging Tips

1. Error Handling

   • Enable debug mode in config/web.php:

     'components' => [
         'errorHandler' => [
             'errorAction' => 'site/error',
         ],
     ],
     

   • Use Yii::error() and Yii::warning() for logging.

2. Logging

   • Configure log component:

     'log' => [
         'traceLevel' => YII_DEBUG ? 3 : 0,
         'targets' => [
             [
                 'class' => 'yii\log\FileTarget',
                 'levels' => ['error', 'warning'],
             ],
         ],
     ],
     

3. Database Debugging

   • Enable query logging:

     'components' => [
         'db' => [
             'enableProfiling' => true,
             'enableLogging' => true,
         ],
     ],
     

   • View logs via Yii::$app->db->getLogger()->logs.

4. Common Issues

   • 404 Errors: Verify urlManager rules and web.php base URL.
   • CSRF Tokens: Ensure Csrf::validate() is called in forms.
   • Session Expiry: Check session component timeout and cookie settings.

Extension Points

1. Custom Components

   • Extend core components (e.g., yii\db\Connection) for reusable logic:

     namespace app\components;
     use yii\db\Connection;
     
     class CustomDb extends Connection {
         public function customQuery() { /* ... */ }
     }
     

   • Register in config/web.php:

     'components' => [
         'db' => ['class' => 'app\components\CustomDb'],
     ],
     

2. Behaviors

   • Attach behaviors to models/controllers for reusable logic:

     public function behaviors() {
         return [
             'timestamp' => [
                 'class' => 'yii\