[KCP] ?? ClassDescription>>classVersion

Ned Konz ned at bike-nomad.com
Fri Jun 27 21:47:22 UTC 2003


On Friday 27 June 2003 02:21 pm, Stephane Ducasse wrote:

> I guessed that too because it is used in SmartRefStream.
> But what does it means exactly, because I cannot believe that only
> four classes changes the structure since 96.
>
> I guess that this is about class structure changes. My point is
> that if this mechanism is good we should really use it
> to ensure backward compatibility. It is used for backward
> compatibility on uniclass when I save a project?
>   Or I do not see the point to only have 4 classes over, 1800 that
> use it. So I want to know more.

What this does is allows you to distinguish between class versions 
when the shape of the class hasn't changed (when there's no change in 
the instVar names).

In the conversion methods you usually can tell by the inst var names 
what old version you have. In a few cases, though, the same inst var 
names were kept but their interpretation changed (like in the 
layoutFrame).

By changing the class version when you keep the same instVars you can 
warn older and newer images that they have to convert.

-- 
Ned Konz
http://bike-nomad.com
GPG key ID: BEEA7EFE



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