Subject: Re: Moving DASL to Experimental

From: "Julian Reschke" <[email-masked]>
Date: Tue, 12 Jun 2001 12:12:23 +0200

Hi,

I'm looking for other parties that would be interested on working on DASL
again. With the current status of the spec I have mainly two problems, both
of which apply to the basicsearch grammar:

1) The spec is completely silent about how the grammar engine is supposed to
know about data types. For instance, I would suspect that property values
for getcontentlength are supposed to be compared as numbers, while
getlastmodified need a date comparison.

2) The grammar for accessing properties is not really XML-friendly, which
has led to inventions like "DAV:iscollection". Indeed, this so-called
"synthetic property" only solves one special case and leaves the rest
(lockdiscovery, attributes, deltaV computed properties) untreated. I think
DASL needs a grammar which can do "arbitrary" queries into the attributes,
so something with the power of XPath would need to be used.

In addition, I'm not happy with the language in chapter 3 (discovery of
grammars). It mixes namespace prefixes with URI schemes, which is only
correct in the very special case of "DAV:" (being a URI scheme and also the
prefix used there).

Julian

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From: "Julian Reschke" <[email-masked]>
Date: Tue, 12 Jun 2001 15:49:30 +0200

Hi,

we just tried to WebDAV-mount an Oracle IFS (1.1) using Microsoft's
webfolder client, and failed.

Inspection of OPTIONS and PROPFIND responses showed:

1) Oracle IFS only supports DAV class 1, and doesn't return an ALLOW header
on OPTIONS,

2) <getetag> is "getetag_blah" for all resources,

3) It tries to return <getlastmodified> in RFC format, but uses it's locale
for formatting, which obviously will not produce an RNC formatted date when
your language isn't english,

4) It tries to return <creationdate> in RFC format (and fails in the same
way), while this should be in ISO8601 format,

5) <getcontentlanguage> (when not "unknown") is set to language strings like
"ENGLISH" (which I think is incorrect according to section 14.13 of
[RFC2068])

Did anybody have more luck trying this?

Julian

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From: "Lisa Dusseault" <[email-masked]>
Date: Thu, 21 Jun 2001 12:10:10 -0700

I'm also interested in working on DASL some more.  Xythos has implemented
it, including the basicsearch grammar :)

Although an XPath or XMLQuery syntax would be useful, basicsearch is also
useful and should not be dropped:
 - it can easily be translated into SQL for clients or servers that already
support SQL
 - it is very simple for very simple tasks
 - it can be implemented even by servers concerned about limiting their
performance "liability", because it can do very high-level searches and
restrict what properties can be searched.  (Servers don't have to support
any features which require parsing of the body or property syntaxes.  Since
parsing can be expensive, XPath/XMLQuery impose a far greater performance
liability.)
 - it's very suited for directory contents listing, filters and sorting --
common browser tasks, easily automated.  E.g. only show items created since
<date>.  Only show items created by <principal>.

lisa

> -----Original Message-----
> From: [email-masked]
> [mailto:[email-masked]]On Behalf Of Julian Reschke
> Sent: Tuesday, June 12, 2001 3:12 AM
> To: [email-masked]
> Subject: Re: Moving DASL to Experimental
>
>
> Hi,
>

---

From: "Jim Whitehead" <[email-masked]>
Date: Thu, 21 Jun 2001 18:01:20 -0700

> it, including the basicsearch grammar :)

The missing element in moving DASL forward once again is someone who is
willing to act as the editor of this specification. A volunteer is needed...

- Jim