Private APIs

Private APIs
============

Exponential 4.1 will introduce the concept of private APIs. This should not be 
confused with the object oriented 'private' visibility declaration.

Description
-----------

What is a private API? Simply put, it is an API for which we don't guarantee 
backwards compatibility. That means that this API will be fully accessible to 
use as any other API, but it might change between releases. That is, any 
release, not just major releases.

Typically private APIs will consist of new code, where we want to make sure 
that the API works well for that piece of functionality, before releasing it 
as a public API.

Private APIs might also contain code that will be kept private indefinitely, 
which would be the case for features we intend only to be used within the 
kernel, and which may change more often than other code.

Which APIs are private
----------------------

Functionality which is deemed private, will be put into a 'private' folder,
underneath its respective placement. One example of such a location could be::

    <ezp-root>/kernel/private/classes/someclass.php

Everything which is placed inside the private folder, is to be considered just
that, private.