Dealloc method in class category

Question

I've been looking at some third-party code that adds a class category to UITableView; the interface adds three methods, but the implementation also includes code for the -dealloc method (among other helper methods).

I'm not super familiar with class categories - aside from this seeming like a bad thing to do, does this override the -dealloc method for all instances of UITableView - even if the category is not imported by a particular class (say a ViewController) that instantiates a UITableView?

Answer 1

Toss that code as it is clearly garbage (post a link to it, if you can).

Assuming it really is a category on UITableView , that dealloc will effectively replace -- override, but without inheritance -- the class's normal dealloc , thereby guaranteeing misbehavior. Not only will it destroy the functionality of all instances of UITableView, it'll mess up all subclasses, too.

Even if it isn't a category on UITableView , but some attempt to organize code, then the dealloc is in the wrong place. It should always be on the class's primary @implementation . Just like a class cluster will implement all primitive methods on the main implementation -- dealloc is very much a primitive method (where a "primitive" method is a method that is core to a class's functionality and is only implemented in terms of other primitive methods).