Revisiting WSDL Compontent Designators

I'm reviewing the draft TAG finding at
http://www.w3.org/2001/tag/doc/abstractComponentRefs-20031030.  Here are
some thoughts:

1) The finding states that using a namespace name for the base of the
identifier is OK (although it does not unambiguously recommend this
practice.)

2) The finding states that instances of the description language should
be available by de-referencing the identifier - this implies that WSDL
should recommend that a WSDL document be available at the
targetNamespace URI and that the WSDL media type registration include
the fragment syntax we agree on.

3) The finding communicates the feeling that some TAG members have that
an XPointer-compatible syntax not be used.  Following the minutes of the
discussion, this appears to be motivated by a belief that unescaped
parentheses are not allowed in fragments.  But from
http://www.rfc-editor.org/rfc/rfc2396.txt:

      fragment      = *uric
      uric          = reserved | unreserved | escaped
      unreserved    = alphanum | mark
      mark          = "-" | "_" | "." | "!" | "~" | "*" | "'" |
                      "(" | ")"

Which clearly shows that parens are allowed (and not even reserved).  I
conclude that this is just a momentary lapse that the TAG will rectify
soon.  I think our XPointer-compatible syntax is good.

I also notice that certain names may not be expressible in "alphanum"
and so we may need to require %-escaping of some characters (assuming we
want a single URI- (not IRI-) compatible string as an identifier.


Proposal

I therefore propose that we adopt the TAG finding (except for the
missing parens):

1) Reintroduce WSDL component designators as an appendix in our
specification (see
http://www.w3.org/TR/2003/WD-wsdl12-20030611/#wsdl-uri-references),
cleaning up the text to remove the issues and rationale and instead just
present our solution.

2) Add a clause to the appendix providing a rule for escaping characters
in component names not allowed in URIs (e.g. name characters other than
alphanum must be %-escaped using UTF-8 byte values).

3) Reintroduce these fragment identifiers as a normative part of the
media-type registration.

4) Add a statement recommending to authors to make WSDL available at the
targetNamespace.

Received on Tuesday, 11 November 2003 14:56:10 UTC