Re: structured documents [draft-hopmann-collection-props-00.txt]

   From: John Stracke <>

   "Geoffrey M. Clemm" wrote:

   > Given that WebDAV already makes significant use of XML, I would propose
   > that using XML as the compound document format should be the default choice
   > unless proven deficient for that purpose.

   Hmm.  Does there already exist an XML DTD for compound documents?

XML provides the mechanisms for specifying "immediate" data and references
to other resources.  A DTD just specifies a particular type of
compound document (or at least, specifies its syntax).  Providing
a MIME namespace and DTD's to support interoperability between MIME and
XML would be fine, but that's very different from using MIME as the
structured document format for WebDAV.

   > I realize that emveryone has their favorite alternative to XML (and MIME
   > certainly has its advantages), but it's rather late in the game to switch
   > from XML to MIME, and depending on both XML *and* some other structured
   > document format (such as MIME) is a complexity I'd prefer to avoid if at
   > all possible.

   We already depend on MIME at least a little bit, because we're based on HTTP.

Can you be more specific?  I don't remember ever feeling the need to read
any MIME spec to understand some part of WebDAV (and I read a *large*
number of specs during my recusive descent into WebDAV-world :-).

   My feeling is that, while XML is a good format for single documents, there is no
   good reason to use it to duplicate the MIME mechanisms.

A good reason would be if XML already provides the required MIME
functionality, and is already an explicit and widely used component of
WebDAV, then the spec is needlessly complicated by introducing MIME.

    MIME is more widely
    deployed, understood, and supported; and it already does what we want.

There are many things that are widely deployed, understood, and supported
than XML (and certainly than WebDAV), but selecting an additional redundant
format just because it is widely deployed is a major step against

  Plus, as a
   (blech) political point, any working group that attempts to reimplement MIME is
   going to face objections from the IETF community, asking why they didn't stick
   with the protocol that was already there.

We are sticking with a protocol that was already there ... it's just that
it is XML, and not MIME.  So I need to see a convincing argument
that MIME provides essential functionality not already provided by XML.

To emphasize, I'm not saying there is no such argument that could be
made -- it's just that I haven't seen it, and I subscribe strongly to the
"keep it out of the spec until proven necessary" philosophy.

   (And God help any working group that
   reimplements MIME and omits an obscure feature in a subclause in RFC 31415926536.

Which illustrates why I would resist seeing MIME as a required part of the
WebDAV spec (:-).


Received on Wednesday, 13 January 1999 13:43:38 UTC