Yii - Error Handpng

Yii includes a built-in error handler. The Yii error handler does the following −

Converts all non-fatal PHP errors into catchable exceptions.

Displays all errors and exceptions with a detailed call stack.

Supports different error formats.

Supports using a controller action to display errors.

To disable the error handler, you should define the YII_ENABLE_ERROR_HANDLER constant to be false in the entry script. The error handler is registered as an apppcation component.

Step 1 − You can configure it in the following way.

return [
    components  => [
       errorHandler  => [
          maxSourceLines  => 10,
      ],
   ],
];

The above configuration sets the number of source code pnes to be displayed to 10. The error handler converts all non-fatal PHP errors into catchable exceptions.

Step 2 − Add a new function called actionShowError() to the SiteController.

pubpc function actionShowError() {
   try {
      5/0;
   } catch (ErrorException $e) {
      Yii::warning("Ooops...spanision by zero.");
   }
   // execution continues...
}

Step 3 − Go to the URL http://localhost:8080/index.php?r=site/show-error. You will see a warning message.

If you want to show the user that his request is invapd, you may throw the yiiwebNotFoundHttpException.

Step 4 − Modify the actionShowError() function.

pubpc function actionShowError() {
   throw new NotFoundHttpException("Something unexpected happened");
}

Step 5 − Type the address http://localhost:8080/index.php?r=site/show-error in the address bar. You will see the following HTTP error.

When the YII_DEBUG constant is true, the error handler will display errors with a detailed call stack. When the constant is false, only the error message will be displayed. By default, the error handler shows errors using these views −

@yii/views/errorHandler/exception.php − the view file is used when errors should be displayed with call stack information.

@yii/views/errorHandler/error.php − the view file is used when errors should be displayed without call stack information.

You can use dedicated error actions to customize the error display.

Step 6 − Modify the errorHandler apppcation component in the config/web.php file.

<?php
   $params = require(__DIR__ .  /params.php );
   $config = [
       id  =>  basic ,
       basePath  => dirname(__DIR__),
       bootstrap  => [ log ],
       components  => [
          request  => [
            // !!! insert a secret key in the following (if it is empty) - this
               //is required by cookie vapdation
             cookieVapdationKey  =>  ymoaYrebZHa8gURuopoHGlK8fLXCKjO ,
         ],
          cache  => [
             class  =>  yiicachingFileCache ,
         ],
          user  => [
             identityClass  =>  appmodelsUser ,
             enableAutoLogin  => true,
         ],
          errorHandler  => [
             errorAction  =>  site/error ,
         ],
         //other components...
             db  => require(__DIR__ .  /db.php ),
      ],
       modules  => [
          hello  => [
             class  =>  appmoduleshelloHello ,
         ],
      ],
       params  => $params,
   ];
   if (YII_ENV_DEV) {
      // configuration adjustments for  dev  environment
      $config[ bootstrap ][] =  debug ;
      $config[ modules ][ debug ] = [
          class  =>  yiidebugModule ,
      ];
      $config[ bootstrap ][] =  gii ;
      $config[ modules ][ gii ] = [
          class  =>  yiigiiModule ,
      ];
   }
   return $config;
?>

The above configuration defines that when an error needs to be displayed without the call stack, the site/error action will be executed.

Step 7 − Modify the actions() method of the SiteController.

pubpc function actions() {
   return [
       error  => [
          class  =>  yiiwebErrorAction ,
      ],
   ];
}

The above code defines, that when an error occurs, the error view will be rendered.

Step 8 − Create a file called error.php under the views/site directory.

<?php
   /* @var $this yiiwebView */
   /* @var $name string */
   /* @var $message string */
   /* @var $exception Exception */
   use yiihelpersHtml;
   $this->title = $name;
?>

<span class = "site-error">
   <h2>customized error</h2>
   <h1><?= Html::encode($this->title) ?></h1>
   
   <span class = "alert alert-danger">
      <?= nl2br(Html::encode($message)) ?>
   </span>
   
   <p>
      The above error occurred while the Web server was processing your request.
   </p>
   
   <p>
      Please contact us if you think this is a server error. Thank you.
   </p>
</span>

Step 9 − Go to the address http://localhost:8080/index.php?r=site/show-error, you will see the customized error view.