W3C home > Mailing lists > Public > www-rdf-comments@w3.org > January to March 2005

pls warn against untested hooks

From: Dan Connolly <connolly@w3.org>
Date: Wed, 02 Feb 2005 12:13:22 -0600
To: www-qa@w3.org
Cc: www-rdf-comments@w3.org
Message-Id: <1107368002.24721.219.camel@localhost>

My experience is that untested hooks are bad; really bad. Please
share this experience with your readers.

This bit of SpecGL seems relevant, though not exactly the "untested
hooks are bad" bumper-sticker I'd like to see:

        Make sure there is a need for the optional feature. 
        4.2 Good Practice A: in 4. Managing Variability of SpecGL 

The 1999 RDF spec had a couple hooks that were not well tested:

[[
When an RDF processor encounters an XML element or attribute name that
is declared to be from a namespace whose name begins with the string
"http://www.w3.org/TR/REC-rdf-syntax" and the processor does not
recognize the semantics of that name then the processor is required to
skip (i.e., generate no tuples for) the entire XML element, including
its content, whose name is unrecognized or that has an attribute whose
name is unrecognized.
]]
  -- http://www.w3.org/TR/1999/REC-rdf-syntax-19990222/

The WG observed that implementations were all over the map,
so we got rid of that one.
http://www.w3.org/2000/03/rdf-tracking/#rdfms-para196


This one was sorta contradictory:

[[
Other values of parseType are reserved for future specification by RDF.
With RDF 1.0 other values must be treated as identical to 'Literal'.
]]

I think the WG observed that implementations follow the latter sentence
and standardized it, though I can't find the decision. There's
a relevant test,

http://www.w3.org/2000/10/rdf-tests/rdfcore/rdfms-literal-is-xml-structure/test005.rdf

which seems to be associated with this issue...
  http://www.w3.org/2000/03/rdf-tracking/#rdfms-literal-is-xml-structure
but I don't see a pointer in the other direction.
I know we decided that using this as a hook for parseType="Quote"
is not allowed:
  http://www.w3.org/2000/03/rdf-tracking/#rdfms-quoting


I think SMIL has some system-foo hooks that are more well tested.
There are plenty of other well-tested, well-used hooks in the
web: HTTP mime types, XSLT extensions, CSS fallback rules (though
those were, at one point, insufficiently tested) etc.

The issue of untested hooks came up recently in a WG meeting
I chaired; in editing the minutes, I was curious if SpecGL
had an "untested hooks are bad" bumper sticker; almost...


[[
SPARQL Protocol Spec
We noted SPARQL Protocol for RDF W3C Working Draft 14 January 2005 ...

Regarding the Abstract protocol, DanC noted that it comes with a testing
obligation; if we're only going to test one concrete protocol, we should
fold the essential material from the abstract protocol into it. He later
clarified that it would be OK if a second concrete protocol (SOAP,
SMTP, ...) were not normatively specified, but only specified in a Note
or even only in the test materials; as long as the abstract protocol
"hook" is tested, we've met our obligations.

postscript: this bit of SpecGL seems relevant, though not exactly the
"untested hooks are bad" bumper-sticker I'd like to see:

        Make sure there is a need for the optional feature. 
        4.2 Good Practice A: in 4. Managing Variability of SpecGL 
]]
 -- http://www.w3.org/2001/sw/DataAccess/ftf4.html#item08

-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
D3C2 887B 0F92 6005 C541  0875 0F91 96DE 6E52 C29E
Received on Wednesday, 2 February 2005 18:13:23 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Friday, 21 September 2012 14:16:33 GMT