- From: David Hull <dmh@tibco.com>
- Date: Tue, 17 Jan 2006 14:31:32 -0500
- To: "Yalcinalp, Umit" <umit.yalcinalp@sap.com>
- Cc: public-ws-addressing-comments@w3.org, Francisco Curbera <curbera@us.ibm.com>
- Message-id: <43CD4614.1090606@tibco.com>
Yalcinalp, Umit wrote: > David, > > I would prefer the specification to be very precise, and NOT confusing. I made a fresh pass at the spec while we were discussing > > another issue and simply the sections contradict each other in 2 > distinct ways (optionality vs. defaults + the meaning of "none"). > > Someone who is not in the WS-Addressing wg should be able to infer the > semantics without getting confused. If we the members of the wg find > it confusing, then it is a CR issue :-) Not disagreeing. > > --umit > > > ------------------------------------------------------------------------ > *From:* David Hull [mailto:dmh@tibco.com] > *Sent:* Tuesday, Jan 17, 2006 8:21 AM > *To:* Yalcinalp, Umit > *Cc:* public-ws-addressing-comments@w3.org; Francisco Curbera > *Subject:* Re: New CR Issue: OPTIONAL or REQUIRED? > > I completely agree that defaults and optionality don't mix. > > However, as I understand it, the current definition is not > inconsistent (just a bit confusing): > > * the response endpoint MAPs are indeed optional > * /in the context of XML infosets,/ a missing reply defaults > to anonymous while the fault endpoint has no default. This > is not inconsistent; it only means that 3.2 says more than > 3.1. It's still entirely possible to speak of an abstract > message with no reply endpoint. You just won't see any > represented in XML. I'm not arguing that this is clear or > sensible, only that it's not inconsistent. > * /in the context of a request-reply operation/, the response > endpoints have further restrictions. > > So the [fault endpoint] really is optional. In particular, you > can leave it off of a one-way message with no harm. The [reply > endpoint] will default to anonymous whenever you use XML (um, > pretty much always, right?), but this is generally regarded as > harmless. > > Yalcinalp, Umit wrote: > >> >> Several sections of the Core Specification [1] are in >> contradiction wrt to the default values for reply endpoint and >> its optionality. Currently the specification treats the reply >> endpoint as a required property instead of an optional property >> and contradicts itself in several sections as follows: >> >> -- Section 3.1 lists reply endpoint/fault endpoint as "optional" >> properties as their cardinality is defined as (0..1) >> >> -- Section 3.2 lists the corresponding headers >> wsa:ReplyTo/wsa:FaultTo as OPTIONAL elements. However, the >> "default" value for the reply endpoint property is designated to >> be anonymous URI. This aspect makes the property required and is >> in conflict with its definition in Section 3.1. Consequently, the >> message exchanges will always assume a response, instead of using >> the URI "_http://www.w3.org/2005/08/addressing/none_". >> >> -- Section 3.3.1 (Formulating a Reply Message) first bullet >> second statement says "If none is present, the processor MUST >> fault.". It is not clear what "none" refers to here. There are >> two possibilities: >> >> (a) There is no reply endpoint property (refers to "0" as in >> Section 3.1). If this is the case, this is in contradiction with >> the fact that there is a value (anonymous) as the "Note" in the >> following paragraph suggests. This is again the reflection of the >> contradiction between the sections in 3.1 and 3.2. Perhaphs the >> intention of this paragraph is to say that there is always a >> reply endpoint property when a reply is expected and it is an >> error not to have a reply endpoint in this case. However, this >> intention itself contradicts the fact that an EPR with an >> anonymous reply endpoint is always assumed which will result in >> ALWAYS having a reply endpoint, deeming it to be REQUIRED, not >> OPTIONAL. >> >> (b) The value of the reply endpoint property is >> "_http://www.w3.org/2005/08/addressing/none_". This case is >> covered in 2, therefore probably (b) is not the intended >> semantics for "none". >> >> Default values and optional values do not mix well. The >> specification should clearly indicate whether the value is >> mandatory and supplied by a default or optional. >> >> Cheers, >> --umit >> >> >> [1] _http://www.w3.org/TR/2005/CR-ws-addr-core-20050817/_ >> >> >> ---------------------- >> >> Dr. Umit Yalcinalp >> Architect >> NetWeaver Industry Standards >> SAP Labs, LLC >> Email: umit.yalcinalp@sap.com Tel: (650) 320-3095 >> SDN: _https://www.sdn.sap.com/irj/sdn/weblogs?blog=/pub/u/36238_ >> >
Received on Tuesday, 17 January 2006 19:31:56 UTC