RE: issue 6398: updated proposal

Geoff wrote:
The current version of T.Create() states that the first child element MUST 
NOT be omitted. But the draft proposal allows senders to emit empty Create 
requests. This means, current Transfer Resource Factories cannot process 
the proposed Create request messages without changing the underlying 
processing logic.

I think we need to move past the notion that existing implementations will 
not need to change - if nothing else the namespace issue will force that - 
so let's just put the nail in that coffin.  To this specific case, if an 
implementation does not support having default values for the entire 
representation then it's free to fault an empty Create.  Just like its 
free to fault a non-empty Create for any number of reasons.

If you'd like to have Create go back to xs:any+ then I'm open to a 
counter-proposal - but then I'd like to see some guidance on how RT fits 
into it - as you pointed out, they're not 'in-sync'.  But, IMO, the 
xs:any* is a far better choice for the long term solution as it provides 
the most flexibility and extensibility.

thanks
-Doug
______________________________________________________
STSM |  Standards Architect  |  IBM Software Group
(919) 254-6905  |  IBM 444-6905  |  dug@us.ibm.com



Geoff Bullen <Geoff.Bullen@microsoft.com> 
Sent by: public-ws-resource-access-request@w3.org
02/03/2009 12:35 PM

To
Doug Davis/Raleigh/IBM@IBMUS
cc
"public-ws-resource-access@w3.org" <public-ws-resource-access@w3.org>
Subject
RE: issue 6398: updated proposal






Hi Doug,
Having re-read our previous email a couple of times, it is still kind of 
unclear exactly what you think we are in agreement on here. J  While it is 
hopeful we will find common ground at some point, we are not there yet.
 
Regarding Transfer Create Operation ?
 
T.Create and RT.Create currently have different cardinalities and one of 
them therefore must change in order for them to remain ?in sync?.
 
The current version of T.Create() states that the first child element MUST 
NOT be omitted. But the draft proposal allows senders to emit empty Create 
requests. This means, current Transfer Resource Factories cannot process 
the proposed Create request messages without changing the underlying 
processing logic.
 
Cheers,
Geoff
 
 
 
From: Doug Davis [mailto:dug@us.ibm.com] 
Sent: Monday, February 02, 2009 5:27 PM
To: Geoff Bullen
Cc: public-ws-resource-access@w3.org
Subject: RE: issue 6398: updated proposal
 

Geoff, 
  thanks for the comments.  I'm glad that we're in agreement that there is 
no functional difference between what the current version of Transfer and 
my proposal because I tried to ensure that it was just a syntax change. As 
to the change of cardinality of Create, I was very clear as to why I 
changed it - please reread my proposal.  Also, it does not break backwards 
compatibility - aside from the addition of a wrapper, existing impls will 
still be sending valid WS-T messages. 

thanks
-Doug
______________________________________________________
STSM |  Standards Architect  |  IBM Software Group
(919) 254-6905  |  IBM 444-6905  |  dug@us.ibm.com 


Geoff Bullen <Geoff.Bullen@microsoft.com> 
02/02/2009 07:32 PM 


To
Doug Davis/Raleigh/IBM@IBMUS 
cc
"public-ws-resource-access@w3.org" <public-ws-resource-access@w3.org> 
Subject
RE: issue 6398: updated proposal
 








Doug,
We have been looking more closely at the wrapper issue (Issue 6398) and 
your current proposal and there are a number of concerns that we have.

Summary
We believe that the proposed changes will affect the current alignment of 
Transfer with HTTP, and that it breaks the current implementation of 
Transfer by changing the cardinality of  message formats.  More specific 
details can be seen below:

1) Wrappers and the Alignment of Transfer with HTTP
We believe that the proposed wrapper changes disrupt the current alignment 
between Transfer and HTTP.  Since the TAG articulated in Nov, 2008 that 
they were interested in a closer alignment between Transfer and HTTP, it 
is unclear to us if this is the right direction for the WG to be heading.

There are a set of principles that guide us as we move through this issue:
 a) Transfer continues to have alignment with HTTP as much as possible.
 b) Transfer is built on WS-A and honors the WS-A action based dispatch 
model.
 c) Transfer should be aligned with Basic Profile as much as possible.

With regards to goal a) above, the HTTP message body carries the content 
(or message body) and not the verb (action).  In the same way, the 
Transfer SOAP body carries the content and not the action. We believe 
using specific wrapper element names, such as <get> and <getresponse>, 
implies there is semantic meaning in those names, which affects the 
separation described above and thus disrupts the existing alignment 
between Transfer and HTTP.  Any semantic meaning also goes against goal 
b).

Also with regards to goal a), the WG has not yet received any technical 
comments from the TAG nor has the TAG articulated its wishes clearly to 
us.  Shouldn't we engage the TAG ASAP?


2) Wrappers, Cardinality and the Create verb
While you expressed a desire to treat cardinality as separate from the 
wrapper issue, your proposal does in fact change the cardinality of the 
Transfer messages, Delete and Create.  While changing the cardinality of 
T.delete does not break backwards compatibility, changing the cardinality 
of T.create certainly does.  It is unclear to us why your proposal has 
chosen to break backwards compatibility with T implementations.  It is our 
understanding that there are many current interoperable implementations of 
the T spec, so would not it be more prudent to align more closely with the 
current version of T?

--Geoff


From: public-ws-resource-access-request@w3.org 
[mailto:public-ws-resource-access-request@w3.org] On Behalf Of Doug Davis
Sent: Sunday, January 18, 2009 10:34 AM
To: public-ws-resource-access@w3.org
Subject: RE: issue 6398: updated proposal


Hey Geoff,
 thanks for the heads up on the cardinality - I'll double check those - 
but what's correct depends on whether you're looking at the schema or the 
text of the spec.  For example, GetResponse, per the pseudo schema should 
be as you noted (+), but per the schema it should be a singleton.  Either 
way - this is our chance to make sure things are aligned. As for the MEX 
change, despite some possible ribbing from Jeff :-), I like consistency - 
so if you open an issue I wouldn't object.

All,
 below is a modified version of the proposal, showing the pseudo schema 
changes to T and RT (some of the cardinalities will vary slightly from 
previous proposal and from the specs in an effort to ensure things are 
consistent and allow for RT to do its job) - I tried to make a note of 
each one as I detected it (hopefully the following shows up ok for 
everyone - if not let me know and I'll put it into a separate file):

T-GetRequest:                 RT-GetRequest:
<wst:Get ... >                <wst:Get Dialect="xs:anyURI" ...>
xs:any *                       <wsrt:Expression ...> xs:any 
</wsrt:Expression> *
</wst:Get>                    </wst:Get>
Note: to allow for more than one Expression, I had to change the 'xs:any 
?' to a "xs:any *" on the xs:any of the T.Get(), and for full 
extensibility (an attribute on Get could make the need for children 
unnecessary).

T-GetResponse:                RT-GetResponse:
<wst:GetResponse ...>         <wst:GetResponse ...>
xs:any +                         <wsrt:Result...>xs:any</wsrt:Result> +
</wst:GetResponse>            </wst:GetResponce>
Note: We should consider changing the "xs:any +" to "xs:any *" since the 
resource representation could technically be empty and we should allow for 
that (<wsrt:Result>+ too), and for full extensibility (an attribute on 
GetResponse could make the need for children unnecessary).

T-PutRequest:                 RT-PutRequest:
<wst:Put ...>                 <wst:Put Dialect="xs:anyURI" ...>
xs:any +                       <wsrt:Fragment ...> +
</wst:Put>                    <wst:Put>
Note: We should change "xs:any +" to "xs:any *" to allow for an empty 
represenation to be 'put', and for full extensibility (an attribute on Put 
could make the need for children unnecessary).

T-PutResponse:                RT-PutResponse:
<wst:PutResponse ...>         <wst:PutResponse ...>
xs:any ?                       xs:any ?
</wst:PutResponse>            </wst:PutResponse>
Note: We should change the "xs:any ?" to "xs:any *" to allow for full 
extensbility.

T-DeleteRequest:              RT-DeleteRequest:
<wst:Delete ...>              <wst:Delete ...>
 xs:any *                      xs:any *
</wst:Delete>                 </wst:Delete>
Note: I added the "xs:any *" extensibility point in here.

T-DeleteResponse:             RT-DeleteResponse:
<wst:DeleteResponse ...>      <wst:DeleteResponse>
xs:any ?                       xs:any ?
</wst:DeleteResponse>         </wst:DeleteResponse>
Note: We should change the "xs:any ?" to "xs:any *" to allow for full 
extensbility.

T-CreateRequest:              RT-CreateRequest:
<wst:Create ...>              <wst:Create Dialect="xs:anyURI" ...>
xs:any *                       <wsmex:Metadata ...> ?
                               <wsrt:Fragment ...> *
</wst:CreateRequest>          </wst:CreateRequest>
Note: I changed the "xs:any +" to "xs:any *" for three reasons: 1) it 
seems like it should be possible to allow the entire resource to have 
default values, 2) per the RT spec the mex and fragment elements are 
optional, 3) to allow for full extensibility (an attribute on the Create 
could make up for the absence of child elements).

T-CreateResponse:             RT-CreateResponse:
<wst:CreateResponse ...>      <wst:CreateResponse ...>
<wst:ResourceCreated>         <wst:ResourceCreated>
xs:any ?                      xs:any ?
</wst:CreateResponse>         </wst:CreateResponse>
Note: We should change the "xs:any ?" to "xs:any *" to allow for full 
extensbility.

We should discuss the "xs:any ?" -> "xs:any *" notes I made - if there 
isn't any objection we can include it as part of this.

thanks
-Doug
______________________________________________________
STSM  |  Web Services Architect  |  IBM Software Group
(919) 254-6905  |  IBM T/L 444-6905  |  dug@us.ibm.com

Geoff Bullen <Geoff.Bullen@microsoft.com>
Sent by: public-ws-resource-access-request@w3.org
01/16/2009 12:09 PM
To
Doug Davis/Raleigh/IBM@IBMUS
cc
"public-ws-resource-access@w3.org" <public-ws-resource-access@w3.org>
Subject
RE: issue 6398: updated proposal







Doug,
A couple of things:
1)      I believe the "xs:any" defined in GetResponse, PutRequest, 
CreateRequest should actually be "xs:any +" defining  one or more.
2)      I am wondering if, for the sake of consistency and extensibility, 
we should also be looking at the GetMetadata Request and Response messages 
in MEX and adding a similar outer wrappers and extensibility concepts?
Thoughts?
--Geoff

From: public-ws-resource-access-request@w3.org 
[mailto:public-ws-resource-access-request@w3.org] On Behalf Of Doug Davis
Sent: Thursday, January 15, 2009 6:36 AM
To: public-ws-resource-access@w3.org
Subject: issue 6398: updated proposal


per my AI from yesterday, the updated pseudo schema for the wrapped 
WS-Transfer operations would be:

GetRequest:
<wst:Get ... >
xs:any ?
</wst:Get>

GetResponse:
<wst:GetResponse ...>
xs:any
</wst:GetResponse>

PutRequest:
<wst:PutRequest ...>
xs:any
</wst:PutRequest>

PutResponse:
<wst:PutResponse ...>
xs:any ?
</wst:PutResponse>

DeleteResponse:
<wst:DeleteResponse ...>
xs:any ?
</wst:DeleteResponse>

CreateRequest:
<wst:CreateRequest ...>
xs:any
</wst:CreateRequest>

CreateResponse:
<wst:CreateResponse ...>
<wxf:ResourceCreated>endpoint-reference</wxf:ResourceCreated>
xs:any ?
</wst:CreateResponse>

In looking at how this impacts RT... it shouldn't. RT overrides T's Body 
(in some cases already using a wrapper similar to the above) so that can 
continue as is. The only thing missing from the previous proposal was the 
extensibilty points on the wrapper elements so that attributes could be 
added - but that was a typo :-) .  Existing RT can continue to override 
the the above messages with a well defined element - this, along with the 
RT header allows the receiver to know this isn't a normal/vanilla Transfer 
operation.

There is no impact on MEX.  I couldn't find any reference to the transfer 
operations that needed to be changed - no samples using it either.

thanks
-Doug
______________________________________________________
STSM  |  Web Services Architect  |  IBM Software Group
(919) 254-6905  |  IBM T/L 444-6905  |  dug@us.ibm.com

Received on Tuesday, 3 February 2009 20:19:04 UTC