Detailed explanation of exception handling in YII Framework tutorial

This article describes YII Framework exception handling. Share it with everyone for your reference, the details are as follows:

Exceptions are everywhere. As a programmer, you live to create these exceptions and then fix them. The YII framework encapsulates PHP exceptions, making exception handling easier.

Configuration method for using YII to handle errors and exceptions:

You can define YII_ENABLE_ERROR_HANDLER and YII_ENABLE_EXCEPTION_HANDLER as true in the entry file.

Things that cause exceptions

1. Trigger the onError or onException event

2. Throw an exception artificially. For example

throw new ExceptionClass('错误信息');//异常的基类
throw new CHttpException(404,'此页面不存在');//面向最终用户的类

Exception display view

When an error is forwarded to the component CErrorHandler, it will select the appropriate view to display the error.
CErrorHandler will search for appropriate views to display error messages. The search order is as follows:

1. WebRoot/themes/ThemeName/views/system: In the system directory under the current theme view.
2. WebRoot/protected/views/system: In the system directory of the application's default view.
3. yii/framework/views: In the standard view directory provided by Yii.

Use action to handle captured exception errors.

Modify the configuration file:

/yii_dev/testwebap/protected/config/main.php
    'errorHandler'=>array(
// use 'site/error' action to display errors
      'errorAction'=>'site/error',
    ),

is used to specify the action for handling errors. For example, the error action
actionError default code in the site controller is as follows

/**
 * This is the action to handle external exceptions.
 */
public function actionError()
{
  if($error=Yii::app()->errorHandler->error)
  {
    if(Yii::app()->request->isAjaxRequest)
      echo $error['message'];
    else
      $this->render('error', $error);
  }
}

In this action, detailed error information is first obtained from CErrorHandler::error. If the obtained information is not empty, use the information returned by CErrorHandler::error to render the error view. The information returned by CErrorHandler::error is an array with the following structure:

code: HTTP status code (such as 403, 500);
type: error type (such as CHttpException, PHP Error);
message: error message;
file: the name of the PHP file where the error occurred;
line: the line where the error occurred;
trace: error call stack information;
source: the context of the code where the error occurred.

Exception log

An error level error message will be recorded when an error occurs. If the error is caused by a PHP warning or notice, then the message will be recorded in the php category; if the error message is caused by an uncaught exception, the category will be exception.ExceptionClassName (for CHttpException , its statusCode will also be appended to the category name). Developers can use these records to monitor error messages and exception handling methods when the application is executed.

I hope this article will be helpful to everyone’s PHP program design based on the Yii framework.

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