Yii: Catching all exceptions for a specific controller - yii

Question

I am working on a project which includes a REST API component. I have a controller dedicated to handling all of the REST API calls.
Is there any way to catch all exceptions for that specific controller so that I can take a different action for those exceptions than the rest of the application's controllers?
IE: I'd like to respond with either an XML/JSON formatted API response that contains the exception message, rather than the default system view/stack trace (which isn't really useful in an API context). Would prefer not having to wrap every method call in the controller in its own try/catch.
Thanks for any advice in advance.

Answer 1

You can completely bypass Yii's default error displaying mechanism by registering onError and onException event listeners.
Example:
class ApiController extends CController
{
public function init()
{
parent::init();
Yii::app()->attachEventHandler('onError',array($this,'handleError'));
Yii::app()->attachEventHandler('onException',array($this,'handleError'));
}
public function handleError(CEvent $event)
{
if ($event instanceof CExceptionEvent)
{
// handle exception
// ...
}
elseif($event instanceof CErrorEvent)
{
// handle error
// ...
}
$event->handled = TRUE;
}
// ...
}

Answer 2

I wasn't able to attach events in controller, and I did it by redefinition CWebApplication class:
class WebApplication extends CWebApplication
{
protected function init()
{
parent::init();
Yii::app()->attachEventHandler('onError',array($this, 'handleApiError'));
Yii::app()->attachEventHandler('onException',array($this, 'handleApiError'));
}
/**
* Error handler
* #param CEvent $event
*/
public function handleApiError(CEvent $event)
{
$statusCode = 500;
if($event instanceof CExceptionEvent)
{
$statusCode = $event->exception->statusCode;
$body = array(
'code' => $event->exception->getCode(),
'message' => $event->exception->getMessage(),
'file' => YII_DEBUG ? $event->exception->getFile() : '*',
'line' => YII_DEBUG ? $event->exception->getLine() : '*'
);
}
else
{
$body = array(
'code' => $event->code,
'message' => $event->message,
'file' => YII_DEBUG ? $event->file : '*',
'line' => YII_DEBUG ? $event->line : '*'
);
}
$event->handled = true;
ApiHelper::instance()->sendResponse($statusCode, $body);
}
}
In index.php:
require_once(dirname(__FILE__) . '/protected/components/WebApplication.php');
Yii::createApplication('WebApplication', $config)->run();

Answer 3

You can write your own actionError() function per controller. There are several ways of doing that described here

Answer 4

I'm using the following Base controller for an API, it's not stateless API, mind you, but it can serve just aswell.
class BaseJSONController extends CController{
public $data = array();
public $layout;
public function filters()
{
return array('mainLoop');
}
/**
* it all starts here
* #param unknown_type $filterChain
*/
public function filterMainLoop($filterChain){
$this->data['Success'] = true;
$this->data['ReturnMessage'] = "";
$this->data['ReturnCode'] = 0;
try{
$filterChain->run();
}catch (Exception $e){
$this->data['Success'] = false;
$this->data['ReturnMessage'] = $e->getMessage();
$this->data['ReturnCode'] = $e->getCode();
}
echo json_encode($this->data);
}
}
You could also catch dbException and email those, as they're somewhat critical and can show underlying problem in the code/db design.

Answer 5

Add this to your controller:
Yii::app()->setComponents(array(
'errorHandler'=>array(
'errorAction'=>'error/error'
)
));