Handling exceptions and returning a response object from a service layer

I have a service layer which is responsible for handling exceptions.

The question is, should I be handling except开发者_JS百科ions in the service layer and how can I pass an appropriate exception message to a view?

class App_Service_Feed {
  function create() {
    //...
    try {
      $feed->getMapper->insert();
    } catch (Zend_Db_Statement_Exception $e) {
      //what do I return here?        
    } catch (Exception $e) {
      //what do I return here?
    }
  }
}

I'm thinking of returning a response object of some description, so that in my controller I manipulate this.

class App_Controller {
  //...
  $response = $service->create();
  if($response->status) {

  }
}

Alternatively, I'm wondering whether to handle exceptions in the controller...

---

Even better than the way of jason bourne (yeah):

class App_Service_Feed {
  function create() {
    //...
    try {
      $feed->getMapper->insert();
    } 
    catch (Zend_Db_Statement_Exception $e) 
    {
      throw new App_Service_Feed_Exception("Your own message", NULL, $e);      
    } 
    catch (Exception $e) 
    {
      throw new App_Service_Feed_Exception("Your other message", NULL, $e);
    }
  }
}

Why is this better?

• You are using your own Exception class (extending Zend_Exception). So you can immediately see where the exception was thrown and you can build in your own additional checks, etc.
• You are passing the last exception along to have more history information (trace) about Exception.

The best way to implement Exceptions is to have a hierarchy of extending Exception classes.

App_Exception extends Zend_Exception
App_Service_Exception extends App_Exception
App_Service_Feed_Exception extends App_Service_Exception

So every folder contains an Exception.php. This way you can catch and rethrow Exceptions on every level, if necessary.

---

All you need to do is throw the exception for Zend Front controller to catch it latter

class App_Service_Feed {
  function create() {
    //...
    try {
      $feed->getMapper->insert();
    } catch (Zend_Db_Statement_Exception $e) {
      throw new Zend_Exception("my own message");      
    } catch (Exception $e) {
      throw new Zend_Exception("my different message");
    }
  }
}

---

You can follow this approach I normally follow it when I use to do exception handling:

class App_Service_Feed {


function create() throws CustomException, OtherCustomException {
    //...
    try {
      $feed->getMapper->insert();
    } catch (Zend_Db_Statement_Exception $e) {
      //you can throw ur custom exception here. 
      //By doing so you can increase its functionality and understand what is the problem
       throw new CustomException();       
    } catch (Exception $e) {
      //here u can check some general exception like NullPointer, IOException etc(related 
      //to ur case) using instanceof.
      throw new OtherCustomException

    }
  }
}

Now in your controller you need to handle this exception and show some message:-

class App_Controller {
  //...
  App_Service_Feed obj = new App_Service_Feed();
  try{  
   obj.create()
  }catch(CustomException c)
   {
     //display message
   }catch(OtherCustomException o)
    {
      //display other message
    }
  }
}