In the Zend Framework library, the current practice (circa 1.10.8) is that library components throw exceptions that extend \[code\]Zend_Exception\[/code\].E.g. the \[code\]Zend_Layout\[/code\] component throws a \[code\]Zend_Layout_Exception\[/code\]In my own ZF library, where I'm adding my own ZF components or extending existing components, I'm throwing a \[code\]Mylibrary_Exception\[/code\] (it's not really called that of course 
I can see that they're going to change some of that in ZF 2.0http://framework.zend.com/wiki/display/ZFDEV2/Proposal+for+Exceptions+in+ZF2My actual question is this:Throughout my MVC application in my controllers/models/views, if I need to throw an exception (and this will be rare, because obviously I'll be handling expected errors in a different way) - BUT if I do need to throw an exception here, what is the best practice in ZF?should I just\[code\]throw new Exception("this is an exception");\[/code\]or should I be creating Exception classes in my ZF modules, similar to how the ZF library is organised. i.e. they have exception classes for each library component, should I have exception classes for each application module?\[quote\] application/modules/user/controllers/UserController.php application/modules/user/forms/UserForm.php application/modules/user/models/User.php application/modules/user/views/scripts/index.phtml application/modules/user/exceptions/Exception.php (class User_Exception) application/modules/user/exceptions/SuperexampleException.php (class User_Exception_Superexample)\[/quote\]I've never seen anyone do anything like that before in ZF, so I'm not sure if it's a good idea or not.UPDATE:To clarify my question further - when raising exceptions in the MVC part of the application (as opposed to the library) - are there any conventions regarding using specific exception classes (like the library does) vs just using the generic Exception class?
I can see that they're going to change some of that in ZF 2.0http://framework.zend.com/wiki/display/ZFDEV2/Proposal+for+Exceptions+in+ZF2My actual question is this:Throughout my MVC application in my controllers/models/views, if I need to throw an exception (and this will be rare, because obviously I'll be handling expected errors in a different way) - BUT if I do need to throw an exception here, what is the best practice in ZF?should I just\[code\]throw new Exception("this is an exception");\[/code\]or should I be creating Exception classes in my ZF modules, similar to how the ZF library is organised. i.e. they have exception classes for each library component, should I have exception classes for each application module?\[quote\] application/modules/user/controllers/UserController.php application/modules/user/forms/UserForm.php application/modules/user/models/User.php application/modules/user/views/scripts/index.phtml application/modules/user/exceptions/Exception.php (class User_Exception) application/modules/user/exceptions/SuperexampleException.php (class User_Exception_Superexample)\[/quote\]I've never seen anyone do anything like that before in ZF, so I'm not sure if it's a good idea or not.UPDATE:To clarify my question further - when raising exceptions in the MVC part of the application (as opposed to the library) - are there any conventions regarding using specific exception classes (like the library does) vs just using the generic Exception class?