AI0003 - variants of WS-Topics to address issue WSN 4.29

[Peter Niblett <peter_niblett@uk.ibm.com>]

I attach three versions of WS-Topics showing the changes to be made to
WS-Topics depending on which of the approaches we take to issue 4.29.

Consider the example where tns2:t3 is an extension of tns1:t1



1. Baseline (no change) is given in
http://www.oasis-open.org/apps/org/workgroup/wsn/download.php/17606/wsn-ws_topics-1.3-spec-wd-02a.doc

In this version the NP is required to insert an ExtensionTopic in every
possible place in the TopicSet document, so all paths are permitted. In
this case tns1:t1/tns2:t3 and tns2:t3.
This means that simple Topic Expression dialect tns2:t3  could be used.

2. The 2a-bis version
(See attached file: wsn-ws_topics-1.3-spec-wd-02a - bis.doc)
In this version the NP is given free hand to choose where and how many
times to insert the ExtensionTopic in the TopicSet, and so can choose which
paths to allow. If it chooses not to allow tns2:t3 then simple Topic
Expressions cannot be used.


3. The 2a-ter version
(See attached file: wsn-ws_topics-1.3-spec-wd-02a - ter.doc)

In this version the NP is required to insert the ExtensionTopic into the
TopicSet just once  - an in the position that permits only the "fully
expanded" path - i.e. tns1:t1/tns2:t3.  Simple TopicExpressions can't be
used, and Concrete Expressions are required to provide the full path. Full
and XPath expressions can use wildcard // to avoid having to spell it out
in full.

4. The 2a-quater version

(See attached file: wsn-ws_topics-1.3-spec-wd-02a - quater.doc)


As in the 2a-ter version the NP is required to insert the ExtensionTopic so
as to permit only the "fully expanded" path - i.e. tns1:t1/tns2:t3.
However the definitions of the dialects are adjusted to permit either
tns1:t1/tns2:t3 or tns2:t3. In the case of Simple and Concrete expressions
(which don't actually refer to the TopicSet document) I added words to
state that path may start from the ExtensionTopic itself. In the case of
Full and XPath it requires the expression to be analysed and if it is found
to start with an Extension Topic, then a // is implicitly prepended.

 All versions preserve the "nesting" of the dialects.. i.e. Simple is a
subset of Concrete, is a subset of Full, is a subset of XPATH.

Peter Niblett

wsn-ws_topics-1.3-spec-wd-02a - bis.doc

wsn-ws_topics-1.3-spec-wd-02a - ter.doc

wsn-ws_topics-1.3-spec-wd-02a - quater.doc