Cakephp 3 - 当传出异常时，var不传输到视图 [英] Cakephp 3 - var not transmitted to view when exception thrown

问题描述

在我的AppController中，我定义了一个必须在我应用程序的每个视图（包括error400.ctp，error500.ctp）中使用的变量：

 public $ before $（$ event）
 {
 parent 
 $ foo ='bar'; 
 $ this-> set（compact（'foo'））; 
} 
  

除非抛出异常（如NotFoundException），否则它的效果很好：I得到以下错误：

未定义的变量：foo in /src/Template/Error/error400.ctp

这是cakephp的正常行为吗？如何解决这个问题？

解决方案

是的，这是正常的行为，基本上发生了什么： >

1. 异常被抛出（ beforeFilter 被调用，取决于它抛出的位置，例如它被称为MissingAction或MissingTemplate，但不适用于MissingController）。




2. 请求处理中止， ErrorHandler 抓住并处理该异常的步骤。




3. 要渲染异常， ErroHandler 使用 ExceptionRenderer ，这又创建了特殊的 ErrorController ，这种替换原始控制器。这也意味着，现在你有完全不同的控制器处理请求（Controller类的新实例），所以即使 beforeFilter 被调用， $ foo 被设置，它不再有效。




4. ExceptionRenderer 将使用自己的 render（）方法来创建错误页面的输出。

要自定义此项，您可以扩展该默认值 ExceptionRenderer ，以便您可以将变量设置为 ErrorController

 <？php 
 //进入src / Error / AppExceptionRenderer 
命名空间App \Error; 
 
使用CakeElement 
 
 class AppExceptionRenderer extends ExceptionRenderer 
 {
 public function render（）
 {
 $ this-> controller-> set（'foo' '酒吧'）; 
 return parent :: render（）; 
} 
} 
  

将此类设置为<$ c $中的默认值ExceptionRenderer c> app.php

  // ... 
'Error'=> [
 // ... 
'exceptionRenderer'=> 'App \Error\AppExceptionRenderer'，
 // ... 
]，
  

所以你需要在两个地方设置全局视图变量。使用模型中的一些常见方法，配置类来读取全局变量或任何适合您的要求。

更多关于自定义错误处理： 扩展并实现自己的异常处理程序

In my AppController, I define a variable that must be used in every views (including error400.ctp, error500.ctp) of my app:

// /src/Controller/AppController.php
public function beforeFilter(Event $event)
{
    parent::beforeFilter($event);
    $foo = 'bar';
    $this->set(compact('foo'));
}

It works well, except when an exception is thrown (like NotFoundException): I get the following error:

Undefined variable: foo in /src/Template/Error/error400.ctp

Is this a normal behavior of cakephp? How could I fix this?

解决方案

Yes, this is normal behaviour, what is basically happening:

1. Exception is thrown (beforeFilter was called depending on where was it thrown, e.g. it is called for MissingAction or MissingTemplate, but not for MissingController).

2. Request handling is aborted and ErrorHandler steps in to catch and handle that Exception.

3. To render the Exception, ErroHandler uses ExceptionRenderer, which in turn creates special ErrorController, that kind of replaces original controller. This also means, that now you have completely different controller handling the request (new instance of Controller class), so even if beforeFilter was called and $foo was set, it is not longer valid.

4. ExceptionRenderer will use its own render() method to create output for error page.

To customize this, you can extend that default ExceptionRenderer, so you will be able to set variables to ErrorController

<?php
// goes in src/Error/AppExceptionRenderer
namespace App\Error;

use Cake\Error\ExceptionRenderer;

class AppExceptionRenderer extends ExceptionRenderer
{
    public function render()
    {
        $this->controller->set('foo', 'bar');
        return parent::render();
    }
}

Set this class as default ExceptionRenderer in app.php

//...
'Error' => [
    // ...
    'exceptionRenderer' => 'App\Error\AppExceptionRenderer',
    // ...
],

So you need to set that global view variable in two places. Use some common method from models, Configure class to read global variables or whatever is suitable for your requirements.

More on custom error handling: Extending and Implementing your own Exception Handlers

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