= HowTo: Adding a new class to the hierarchy =
[[TOC]]

The class hierarchy in Orxonox is controlled by [wiki:doc/Identifier Identifiers]. Every class has it's identifier. This page explains how a new class is added correctly to the class hierarchy.

Features available to classes in the hierarchy:
 * [wiki:howto/Identifier Identifier]
 * [wiki:doc/Factory Factory]
 * [wiki:howto/Iterator ObjectLists]
 * [wiki:howto/ConfigValue Config-Values]
 * [wiki:howto/XMLPort XML-Loadable]
 * more...

== Objects ==
If you want to create a new object (an object in the sense of a game-related class), you have to inherit directly or indirectly from [wiki:doc/BaseObject] and call '''RegisterObject('''''ClassName''''')''' (see [wiki:doc/CoreIncludes]) in the constructor of this class.

If you want this class to be [wiki:doc/Loader loadable] from an [wiki:doc/XMLPort XML-file], add '''CreateFactory('''''ClassName''''')''' outside of the code. This creates a mapping between the string "ClassName" and the class itself (see [wiki:doc/Factory]).

*.h file:
{{{
#include "core/BaseObject.h"

class MyClass : public BaseObject
{
    public:
        MyClass();
};

or

#include "objects/SomeOtherObject.h"

class MyClass : public SomeOtherObject
{
    public:
        MyClass();
};
}}}

*.cc file:
{{{
#include "core/CoreIncludes.h"

CreateFactory(MyClass); // optional

// Constructor:
MyClass::MyClass()
{
    RegisterObject(MyClass);
}
}}}

== Interfaces ==
Interfaces in Orxonox aren't objects by themselfes, but provide functions and features for real objects. Those objects inherit from the interfaces, additionally to [wiki:doc/BaseObject] (or a derivative).

Interfaces have to inherit virtually from [wiki:doc/OrxonoxClass] and call '''RegisterRootObject('''''InterfaceName''''')''' in the constructor.

*.h file:
{{{
#include "core/OrxonoxClass.h"

class MyInterface : virtual public OrxonoxClass
{
    public:
        MyInterface();
};
}}}

*.cc file:
{{{
#include "core/CoreIncludes.h"

// Constructor:
MyInterface::MyInterface()
{
    RegisterRootObject(MyInterface);
}
}}}