OOP - overloading a child and its parent class in the same time?

Question

Hi,

I'm working with a framework, but for sometimes I need to alter some methods by overloading classes.

My problem is when a class B inherits from a class A and where I need to overload them both, eg:

class B extends A {}

First I overload A and B, in order to alter some of their methods:

class AA extends A {}
class BB extends B {}

But then what to do for BB extends from AA

In others words ('<--' means extends):

class B   <---  class A
   ^               ^
   |               |
   |               |
class BB  <-?-  class AA

Answer 1

i think you might be looking for Composition

Answer 2

Yes. This is where Traits or Composition comes to play.

Basically, traits in programming concept is a group of functionality that you can include into any class. Think of traits as just a set of functions you can add to your classes.

Answer 3

What you want to accomplish is called multiple inheritance, but that is not supported by PHP and most other recent languages. There is rarely a good reason to use multiple inheritance, and since it can be confusing, it is generally frowned upon.

As mentioned, you can probably achieve what you want in à clean wat through composition, but without more information about your classes, it is impossible to give Amy specific advice.

Answer 4

A good rule of thumb is always prefer composition over inheritance. Once you start thinking that way and almost always using composition, the decision when to use inheritance becomes pretty obvious.