Re: Class Properties in Interfaces?

On Wed, 2008-04-30 at 00:27 -0400, Nathan Nobbe wrote: > On Wed, Apr 30, 2008 at 12:05 AM, Robert Cummings > > Abstract classes and interfaces are not the same. They are > used for > fundamentally different reasons. An interface is to enforce a > contract > for all implementations of the interface. Therefore if I were > to create > an interface with an interface property of x, then all > implementations > using that interface would know that property x exists and > could use it > thusly without having to check for it's existence. > > i am fully aware of the differences between interfaces and abstract > classes. however, if a public method is defined on any class, > abstract or concrete, it may be used without checking by client code; > i believe thats the entire point.. > > Using an abstractclass is a hack, it's not sufficient for > enforcement, and you can't > combine multiple abstract classes as you can with interfaces. > > abstract classes have their place. primarily they are well suited for > template method because some methods can be forced to be implemented > by children and others can be optionally overridden. > > and lastly, coming to multiple inheritance (for lack of better > terminology); that is the only argument with any value for adding > public attributes to the interface construct; however i am still not > receptive to it. from my perspective data is an implementation > detail, period. We are not talking about data here. We are talking about properties. Data is assigned to a property which is akin to functionality being assigned to a method. A property has all the features of the most simple getter/setter method combination in one fell statement and without the envelope overhead. As such, there is no reason why it could not be part of the interface design. Cheers, Rob. -- http://www.interjinn.com Application and Templating Framework for PHP