Re: about objectclass

["Kurt D. Zeilenga" <Kurt@OpenLDAP.org>]

At 04:17 PM 8/11/99 +0800, cellecial@21cn.com wrote:
>In rfc2247(Using Domains in LDAP/X.500 Distinguished Names),Section 5 ,I read
>such lines:"This section defines 2 object classes.The first,dcObject,...as 
>Auxiliary class.The second,domain,...is a structural objectclass."
> 
>I can't find dcObject in slapd.oc.conf and rfc2256.

dcObject should be added (especially since the quick guide uses it).
	objectclass dcobject
	    requires
	        objectClass,
	        dc

>And some objectclass (such 
>as inetOrgPerson which I see on this newsgroup) can't be found in slapd.oc.conf.

It's not possible to list all objectclasses in the distribution
schema definition.  1.x currently includes schema definitions
from U-Mich LDAP 3.3.  I just added dcObject, uidObject,
and referral for completeness.  I rather defer a slapd
schema updating until 2.0.

If you need a 1.x compatible for a particular standard-track
schema item, just ask (on this list).  It's likely that someone
has created exactly what you are after.

>Where to find the latest objectclasses?

Depends on the objectclass.  The core objectclasses are defined
by RFC.  For others, you need to go to the source, whatever that
be.  (inetOrgPerson is defined in an Internet Draft.  You can
get a copy of this at http://www.ietf.org/).

>There are little attributes in slapd.at.conf.Where to find all attributes?

Only non-CES attribute types are listed.

>And I know organizationPerson is subclass of Person. Is there any file which
>shows explictly the inheritance relationship among objectclasses?

In 1.2, inheritance relationships are not maintained by the server.
You must do it manually (by expanding objectclass definitions and
expanding objectclass values in entries).

If you want to know what the superior objectclass of an objectclass
is, you must search various other documents (namely a handful of
RFCs).  There are a few schema browsers on the net (see archives
or FAQ for urls) which can aid in your search.

>If I define a
>new objectclass, how to define it as a subclass of "Person"?

1.2 doesn't have a syntax for specifying such.  You need to
manually expand your objectclass to include the required/may
attributes of person and then list both your objectclass and
person with entries you create.

Another approach is not to subclass person, but augment it
with auxilary objectclass.  For example, dcObject can be
used to augment any objectclass to allow specification
of dc attributes.