Re: Best practice concerning Exceptions

On Thu, Mar 11, 2010 at 9:05 AM, Auke van Slooten <auke@muze.nl> wrote: > Michael Gauthier wrote: > >> On Thu, 2010-03-11 at 10:51 +1030, Daniel O'Connor wrote: >> >>> On Thu, Mar 11, 2010 at 1:07 AM, Auke van Slooten <auke@muze.nl> wrote: >>> >>> I find that most people (myself included) just rely on a general category >>> of >>> exception; and rarely if ever make use of exception codes. >>> >>> [snip] > > Hi Auke, >> >> I typically create a new exception class for each category of error and >> then use codes to distinguish specific errors in those categories. I >> like to use and extend the built-in SPL exceptions where applicable. >> >> For example, in a web service API wrapper, I might have: >> >> * Foo_Exception >> * Foo_HttpException >> * Foo_AuthenticationException >> >> Then I might have more specific exceptions for specific circumstances. >> >> When deciding whether or not to create a new exception class, I think >> about how it would be to write error handling code for the error in >> question, and think about how the error should be logged. >> > > Hi, > > thanks for answering. I've changed the API to incorporate more Exception > classes. Still just four though, I couldn't think of any usefull case for > more... > > I like the idea of using common SPL exceptions, but unless I'm mistaken you > lose the ability to catch any library with one catch() statement? Currently > all my exceptions inherit from the main exception class, so you can just > 'catch( Ripcord_Exception $e )' and any exception the library throws will be > caught. Using SPL exceptions, you would either also have to catch the SPL > base exception or simply catch all exceptions. > > BTW, I've kept the unique error codes, since I think it's easier to use if > you just want to have a single error handler and it adds no extra overhead. > > > regards, > Auke van Slooten > Muze > Hi Auke, To help with your concern, have a look at how we're organizing exceptions in PEAR2 -- http://wiki.php.net/pear/rfc/pear2_exception_policy#full_code_example In short, you use a base exception *interface* rather than *class* for your package's "core" exception. Your concrete exception classes can then extend SPL exceptions while implementing your package's exception interface, thus making *both* characteristics catchable. Hope that helps... -- CRB