NSKeyedArchiver implementation...

[Gregory John Casamento]

All,

For the past few months some members of the team have been trying to implement
keyed archiving in a manner compatible with MOSX.  This is difficult.  Here are
a number of reasons why:

1) We need to reverse engineer each and every class in the class hierarchy.
2) We need to, in some cases, match or emulate the Apple class hierarchy.  
This is particularly the case when with private classes.

Using the archivers methods will be tricky to force some of this as many of the
attributes in the hidden classes are, by necessity different.  So, I believe
that it will be easier to use a tool more suited to the job.  What I believe is
slightly better is to implement keyed archiving in our own way and provide a
way to be compatible with MOSX, if necessary. :)

We can do this by way of an XSLT transformation.   XSLT will allow a
transformation from the XML format which is produced for Apple archives to be
directly translated into XML needed for the NSKeyedArchiver/NSKeyedUnarchiver
format.   This has serveral advantages:

1) It will allow us to complete the implementation of GNUstep's own XML
formatted archives more quickly and in a less kludgy manner.
2) We will not need to rely on the limited nature of some of the tools which
are provided in NSKeyedArchiver/NSKeyedUnarchiver for "translation" of Apple
archives.
3) It allows us to make our XML implementation as robust as we wish without
being bound by Apple's implementation.

It should be possible for us to add some extensions to the API which will allow
the user to specify a stylesheet to be used.  It may also allow some other
types of things to take place in the transform which may be useful.

This is a suggestion, please let me know your thoughts, flames, whatever...

GJC

=====
Gregory John Casamento 
-- CEO/President Open Logic Corp. (A Maryland Corporation)
#### Maintainer of Gorm for GNUstep.