- From: David Hull <dmh@tibco.com>
- Date: Thu, 14 Jul 2005 15:28:35 -0400
- To: Martin Gudgin <mgudgin@microsoft.com>
- Cc: Katy Warr <katy_warr@uk.ibm.com>, public-ws-addressing@w3.org
- Message-id: <42D6BCE3.5070000@tibco.com>
Martin Gudgin wrote:
> OK, I'm confused.
>
> Why do you conclude that the answer to my question "Given that the
> wsa:Action header is mandatory, isn't it the presence of that header?"
> is 'No'.
>
> I would have come to the opposite conclusion;
>
> I have an endpoint that understands WS-Addressing. It receives a
> message that contains wsa:ReplyTo but no wsa:Action. It generates a
> fault. Seems pretty straightforward to me.
Sure. That is a perfectly straightforward rule. In fact, it's implied
by what we say in section 3.3.
I thought you were trying to answer the question "When is an incoming
message deemed to be a WS-Addressing message and therefore subject to
the appropriate WS-Addressing validation?" with (rephrasing the reply as
a statement) "It's subject to WSA validation if the wsa:Action header is
present." And of course, this clearly won't work, since it specifically
doesn't try to validate a message with wsa:ReplyTo and no wsa:Action.
If you meant something else, then never mind. It's probably not worth
sorting.
>
> I have an endpoint that doesn't understand WS-Addressing. It receives
> a message that contains one or more wsa: headers, it either ignores
> them or generates a mustUnderstand fault depending on whether those
> headers are marked mustUnderstand='true' or not. Again, seems pretty
> straightforward to me.
Sure. As I said, we're talking about behavior of endpoints, not
properties of messages.
As DaveO says, the interesting case is that of an endpoint that wants to
accept non-WSA messages without complaint but also handle WSA messages
properly.
>
> Gudge
>
> ------------------------------------------------------------------------
> *From:* David Hull [mailto:dmh@tibco.com]
> *Sent:* 14 July 2005 18:02
> *To:* Martin Gudgin
> *Cc:* Katy Warr; public-ws-addressing@w3.org
> *Subject:* Re: LC 76 - What makes a msg WS-A?
>
> Martin Gudgin wrote:
>
>>
>>
>> ------------------------------------------------------------------------
>> *From:* David Hull [mailto:dmh@tibco.com]
>> *Sent:* 14 July 2005 16:32
>> *To:* Martin Gudgin
>> *Cc:* Katy Warr; public-ws-addressing@w3.org
>> *Subject:* Re: LC 76 - What makes a msg WS-A?
>>
>> Is this really a question of how to support both WSA and
>> old-style HTTP requests on the same endpoint?
>> [MJG] I don't know, I didn't ask the original question.
>>
> Hmm ... my message was in-reply-to yours, but the question was
> really aimed more at Katy. Maybe we need BPEL here :-).
>
>>
>> I.e., if I don't see any WSA headers at all, I assume it's
>> an old-style request and act accordingly, but if I see
>> anything WSA, I follow the rules in section 3?
>> [MJG] I guess one could do that...
>>
> Well, one should do /something/ to ensure that old-style requests
> are accepted as such.
>
>>
>> The tricky bit is that, since MAPs like [destination] and
>> [reply endpoint] can default, a message with no wsa: elements
>> on the wire could still be assigned values for some of its
>> MAPs, since the /infoset/ will still have values for the
>> corresponding elements.
>> [MJG] Which Infoset are you talking about? The XML Infoset
>> has no such values.
>>
> Sorry, I didn't get that quite right. I was going by section 3.2,
> particularly the descriptions of wsa:To:
>
> This OPTIONAL element (whose content is of type xs:anyURI)
> provides the value for the [destination] property. If this
> element is NOT present then the value of the [destination]
> property is "http://www.w3.org/@@@@/@@/addressing/anonymous".
>
>
> (and similarly for wsa:ReplyTo). I initially misread this as
> stating that the element defaulted, as opposed to the MAP. So
> s/since the /infoset/ will still have values for the corresponding
> elements/since the properties are defaulted in the absence of the
> corresponding elements in the infoset/. This sort of confusion
> could be seen as an argument against the two-layered approach (or
> simply as an argument that I read too quickly).
>
> In any case, you can't simply look at the abstract properties and
> say "some WSA properties are defined, so it's a WSA message".
>
>>
>> So either we have to drop down to look at the infoset
>> level, and in particular at the non-defaulted elements in the
>> infoset, or we have to find some marker that can't be
>> defaulted away. This is why the [action] property looks
>> significant here. But on the other hand, what if I include a
>> wsa:ReplyTo element and no action? By the "it's WSA iff
>> [action] is present" rule, that's not a WSA message and
>> therefore not an error. This seems wrong.
>> [MJG] Why does it seem wrong?
>>
> It seems wrong not to fault for a message that contains a
> wsa:ReplyTo on the wire but not a wsa:Action.
>
>>
>> Put another way, when would one get a fault for omitting
>> [action]?
>> [MJG] Whenever another wsa: header is present in a message.
>>
> In other words, the answer to your question ("Given that the
> wsa:Action is mandatory, isn't it the presence of that header?")
> is "No."
>
> This is why at the Berlin meeting we tried to make sure that all
> the possibilities were covered for various combinations of the
> MAPs. I believe we've satisfied ourselves that they are, but
> perhaps we need to revisit this work?
>
>>
>>
>> Martin Gudgin wrote:
>>
>>> Given that the wsa:Action is mandatory, isn't it the
>>> presence of that header?
>>>
>>> Gudge
>>>
>>> ------------------------------------------------------------------------
>>> *From:* public-ws-addressing-request@w3.org
>>> [mailto:public-ws-addressing-request@w3.org] *On Behalf
>>> Of *Katy Warr
>>> *Sent:* 14 July 2005 16:07
>>> *To:* public-ws-addressing@w3.org
>>> *Subject:* LC 76 - What makes a msg WS-A?
>>>
>>>
>>> Please could we discuss the following in the context of
>>> LC76?
>>>
>>> When is an incoming message deemed to be a WS-Addressing
>>> message and therefore subject to the appropriate
>>> WS-Addressing validation? Is it based on the presence
>>> of any WS-addressing Message Addressing Property? For
>>> example, does a message containing a reference parameter
>>> (but no other WS-Addressing information) need to result
>>> in a MessageAddressingHeaderRequired? Or, for
>>> example, does the declaration of the wsa namespace
>>> rendor the message WS-Addressing?
>>>
>>> Thanks
>>> Katy
>>>
>>
>
Received on Thursday, 14 July 2005 19:28:48 UTC