DAML, DirXML, DSML 2.0 - let the fun begin

[Rob Weltman <robw@coscend.com>]

  After a hiatus of a few months, it's time to restart the discussions on the goals and direction of DSML 2.0. When we last met (virtually speaking), Andy Harjanto of Microsoft had put together a strawman proposal for what DSML 2.0 could look like. 
  See:

   http://lists.oasis-open.org/archives/dsml/200010/msg00004.html

and the discussion that followed (Samples...) in:

   http://lists.oasis-open.org/archives/dsml/200011/maillist.html

  The two main focus points of the discussions were:

- Can LDAP's aggregation of object classes in an entry be represented in XML in a way that is compatible with XML Schema, with higher-level object rendering than DSML 1.0 (which was pretty much a transliteration of LDIF into XML)?

- Should LDAP operations (add, modify, delete, moddn, search) be represented as XML elements, or is it possible/desirable to express them as XPath/DOM operations on a directory as a virtual XML document?

  Andy's proposal didn't solve the first problem, and adopted the "operation as XML element" approach to the second one. Examples:

<MyCompany  rdn="OU=MyCompany"  dn="..." description="..." class="...">
    <SalesAndMarketing rdn="OU=SalesAndMarketing"  homePage="..." class="...">
         <Consulting  rdn="CN=Consulting" >
         </Consulting>
   </SalesAndMarketing>
   <ResearchAndDevelopment rdn="OU=ResearchAndDevelopment" description="...">
       <ProductX rdn="CN=ProductX"  startDate="01/02/1998">
       </ProductX>
       <ProductY rdn="CN=ProductX"  startDate="04/02/1999">
       </ProductY>
   </ResearchAndDevelopment>
</MyCompany>

  <update path="guid:a7fc61cc4661924e98f5316ff060baeb" >
     <sn>Gibbs</sn>
     <telephoneNumber op="delete">(425)777 7777</telephoneNumber>
     <telephoneNumber op="append">(206)999 9999</telephoneNumber>
     <telephoneNumber op="append">(425)888 8888</telephoneNumber>
  </update>
  <update path="dn:CN=JSmith, OU=Marketing, O=Example, C=US" >
     <sn>Gibbs</sn>
     <telephoneNumber op="delete">(523)777 7777</telephoneNumber>
  </update>

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  Fast forward to March 2001 and we have three new contributions:

DAML    http://lists.oasis-open.org/archives/dsml/200103/msg00003.html
DirXML  http://lists.oasis-open.org/archives/dsml/200103/msg00004.html
XMLDAP  http://lists.oasis-open.org/archives/dsml/200103/msg00001.html

  Here is my brief summary:

  DAML is an XML wire-level alternative to ASN.1 for LDAP. It's an interesting idea, and it could have saved many of us a lot of difficult debugging if it had been the wire protocol of choice for LDAP. But I'm not sure where it fits in with application-level access to directory data.

  DirXML is a more extensive language along the lines of DSML 1.0 (but different) for representing directory entries and adopting the "operation as XML element" approach for representing directory operations. The submitted documents are HMTL versions of DTDs. It would be nice to have an overview, or a complete sample document conforming to the DTDs, but I think I see representations for all the LDAP operations referenced in DTD-TREE.html. I don't see how you can express a search other than exact match on an attribute value (e.g. no substring match), though. DirXML looks (from the submitted DTDs) like a schema for synchronization between an NDS directory and an application.

  XMLDAP is an XML gateway to LDAP - not in itself an XML language for accessing directories. However it includes an XML tag library for acessing LDAP directories using another "operation as XML element" approach. XTL (XML Template Language, the language that includes LDAP access tags) is used to inject directory data into an XML document as part of page preparation (HTML, WML, other XML). XTL doesn't include an XML representation of directory entries.

  Hopefully that was enough fuel to reignite the discussions on this mailing list and get us moving towards (first milestone) a requirements document.

Rob