W3C

- DRAFT -

SML f2f Redmond, second day 10-16-2007

16 Oct 2007

See also: IRC log

Attendees

Present
Kumar, MSM, Sandy, Jim, Ginny, Pratul, Valentina, John, Kirk, Marv, Zulah
Regrets
Chair
Pratul
Scribe
Valentina

Contents


continue discussion on 5171

http://www.w3.org/Bugs/Public/show_bug.cgi?id=5171

John: producer may not understand all relative URI's
... if the consumer has these schema available he may be able to understand them

<johnarwe> if the producer is serializing content, some GEDs may be matching wildcards. if an element matches a wildcard to the producer, it cannot know if relative URIs are contained within the wildcard-matching elements.

Pratul: SMLIF is just a package and the spec should only talk about the content; everything else is out of scope ( such as how a consumer should process some information )

<johnarwe> the consumer on the other hand may have schemas available that allow it to recognize the elements (that the producer sees as wildcard matches)

<johnarwe> therefore the consumer would find an unmodified relative URI and it would not be correctly interpreted

Ginny: how does the producer know what needs to fix in the IF document ; (question relative to the anyURI contained by the IF document) ?

Pratul: do we have agreement on bug 5171 or we should move to thenext bug on the list ?

Sandy: as long as you take a set of documents and package them in the IF document, their base uri is lost
... how the consumer know how to unpack the documents ?

Kumar: in SQL implementations, data is not stored as file system
... so the unpacking of the documents is not an issue here

Pratul: discusses an IF sample

Kumar: there are 4 places from where you can get the document base URI
... the producer should make sure the document content is right so that the consumer can understand it

Sandy: there is some information available on base URI that is not in the IF ( for example on the file system if file location ); do you suggest to add this to the IF document ?
... but what if I already have an xml:base attribute ?

Pratul: if there is already one don't add another one

Kumar: document aliases in IF does not represent location, is just a way to identify a document

Sandy: a consumer should be able to consume IF documents produced by any producer
... so a consumer needs to have some information in the IF describing how to process the relative URI's

Ginny: can the consumer use the base uri defined for every IF document ?

Sandy: yes, but only when this information is available

Pratul: using base uri for every document is not seen as a requirement; the producer may choose to use it, if necessary
... if relative uri's are used in documents, the producer may probably want to use base uri to define the base in IF

Kumar: if the producer doesn't understand what is producing how can we assume that the consumer should understand this information?
... can we summarize what we found before we move to the next topic ?

John: we need first to understand if we have consenus on what we discussed as valid and supported scenarios

Kumar: will try summarize the discussion..

Pratul: one issue was that fragment only identifiers should not be fixed by applying absolute URI
... second issue : the value of the uri base in IF should be an absolute URI and only one base URI should be defined in an IF document
... how to preserve absolute URI when documents are packaged in IF , when the producer doesn't understand the URI?

Kumar: summarizes the issues on the board : 1. relative URI understood by the producer; 2. relative URI not understood by the producer
... question : should the producer fix relative URI's for the case the producer understand them ?

Ginny: expectation that producers will produce content they don't understand

Kumar: question : should the producer understand all the information in the IF document ?
... notes that implicit notion of structure in relative uri is lost when packaged in IF

Ginny: what is the next action ?

<scribe> ACTION: Kumar toreview 5171 with Sandy and come back with a proposal [recorded in http://www.w3.org/2007/10/16-sml-minutes.html#action01]

<trackbot-ng> Created ACTION-134 - Toreview 5171 with Sandy and come back with a proposal [on Kumar Pandit - due 2007-10-23].

bug 5177 http://www.w3.org/Bugs/Public/show_bug.cgi?id=5177

Resolution: editorial

bug 5181 http://www.w3.org/Bugs/Public/show_bug.cgi?id=5181

Pratul: already discussed, make it dependent on 5171

Ginny: already depends on 5878, which is already resolved

Sandy: Ithink 5171 should be dependent on this one and not the other way around

Kumar: sure, let's do it as Sandy suggests

Resolution: make 5171 dependent on 5181

defect 4636 http://www.w3.org/Bugs/Public/show_bug.cgi?id=4636

Pratul: the proposal is to move from xpointer(), Kumar proposes an alternate solution

MSM: this may contradict with the way the web architecture works
... understands the need for the proposal though

Pratul: what is the problem with this proposal ?

MSM: I think we'll get comments that we took over the task of defining the fragment identifier scheme
... suggest taking the task of asking for xpath1() scheme become a recomendation
... if we don't want to use xpointer() scheme because is not a rec, it's less work if we try to make this a scheme rather than try to use something else

Pratul: we can define our own scheme in the context of the SML spec; faster than to wait for somebody else to make something a rec

MSM; polite to communicate with the XPath language group and tell them we need this and ask them if they plan for having this as a rec; if not, we plan to address this within our group

Kumar: wonder why this has not been a rec yet and why we can succeed on this in a faster manner?

MSM: probably nobody needed our level of standardization
... we should ask other group to ake this a rec; if not we can mmake it part of our spec but probably part of a different document so that it can be reused

Pratul: nervous that this means slipping our own dates
... this is also not part of our charter

MSM: seems that how to deal with fragment identifier is part of our spec though

Kumar: a different document may pose a risk to our current dates, we are close to the LC milestone

John: for the record, Paul Groso is okay with us using xpath1() scheme

Ginny: we can define a scheme for xpointer() in our own spec - one option

John: wonders which of the proposed approaches is more likely to go smoothly

Pratul: as a compromise we can use the xpath1() scheme and then have an action to follow up with the wrc group to test if this may be an issue; if an issue, we can incorporate this in our scheme

Kumar: propose to define our own xpath1() scheme, choose a name for it and add it as a part of our spec

Ginny: we should also register this scheme

John: wonders what is the process for registering a scheme

Kumar: asks MSM if he is aware of the FixPointer activity and how this relates to the xpointer() scheme since the FixPointer group were originally part of the xpointer() group

MSM: irreconcilable differences between people who wanted reach support for references resulted in this new activity
... FixPointer is not actively proposed by anyone

Pratul: for this bug we have two options; 1. define our own scheme; 2. use xpath1() scheme
... Kumar is not comfortable with option2; he proposes option 1

John: we need to review the scheme registration process so that we know what can be done in terms of updating existing schemes so that we don't end up with issues

Kumar: agrees to review this process; due diligence on the procces

Resolution: use xpath1() scheme

Pratul: next question is whether we want to create a profile of the xpath1() scheme and use Kumar's proposal
... proposes to close 4636 and comment that the decision is to use xpath1()

Kumar: options 1. use xpath1() as is, 2. profile xpath1() 3. define our own scheme

Pratul: to summarize proposed approach: use xpath1() scheme and communicate with the wrc team to see if there are any issues with this approach; if any issues are identified then we go with defining our own scheme

<scribe> ACTION: Kumar to investigate if there any implemetation issues with supporting xpath1() scheme [recorded in http://www.w3.org/2007/10/16-sml-minutes.html#action02]

<trackbot-ng> Created ACTION-135 - Investigate if there any implemetation issues with supporting xpath1() scheme [on Kumar Pandit - due 2007-10-23].

Resolution: get back to this defect after Kumar and Pratul/John/MSM investigates issues with the proposed xpath1() scheme usage

bug 4639 http://www.w3.org/Bugs/Public/show_bug.cgi?id=4639

Ginny: there is a document posted with the latest proposal

latest proposal http://lists.w3.org/Archives/Public/public-sml/2007Oct/0066.html

<johnarwe> http://lists.w3.org/Archives/Public/public-sml/2007Oct/0066.html

Ginny: the proposal is to specify that cycles are defined on elements; suggestion is to replace the existing document cycle as described in the spec
... acyclic can be specified on any complex type
... are annotations inherited ?

MSM: no, they are not
... only attributes and content model are inherited
... a way to make an annotation inherited, is to somehow add it to an attribute

Ginny: an element can have more children which are ref; this definition allow to define acyclic on specific child
... use sml:acyclic ref attribute to describe the elements on which acyclic should be enforced

Sandy: comments that acyclic can be inherited by making this a requirement in the SML spec; this is how we deal now with other SML inherited properties, sml:key
... the proposal is to make the acyclic properties inherited - should be applied on that type or inherited types

Jim: can this be implemented using schematron rules ?

MSM: only if you use XPath 2.0 and define a recursive function to keep deref'ing the references

Kumar: what if the acyclic is defined on the child instead of the parent and define cyclic any graph getting back to that element or the parent of that element

Sandy: it may not be necessarily on any ancestor

The discussion is around two options on how to define acyclic ; 1. define it at the ancestor level, which bounds it with a node type 2. define it at the reference level

the current proposal ( posted on the bug ) refers to option 1

sample for option 2:

<CT 'nodeType'>

<seq>

<e n="left" sml:acyclic="./left"/>

<e n="right" sml:acyclic="./right"/>

</seq>

</CT>

sample for option 1:

<CT nodeType>

<annotation>

<sml:acyclic ref="./left"/>

<sml:acyclic ref="./right"/>

</annotation>

<seq>

<e n="value"/>

<e n="left"../>

<e n="right"../>

</seq>

</CT>

Pratul: propose to resume the discussion at a later time

Jim: should we try to understand what options, 1 or 2, are considered at this time ?

Sandy: option 2 covers the case where the refs don't share the same parent type

break for lunch

Resolution: open action item against Ginny to update the proposal based on today's discussions

<scribe> ACTION: Ginny to update acyclic proposal to include the options discussed in the 10/16/07 f2f meeting [recorded in http://www.w3.org/2007/10/16-sml-minutes.html#action03]

<trackbot-ng> Sorry, couldn't find user - Ginny

<scribe> ACTION: Virginia update acyclic proposal to include the options discussed in the 10/16/07 f2f meeting [recorded in http://www.w3.org/2007/10/16-sml-minutes.html#action04]

<trackbot-ng> Created ACTION-136 - Update acyclic proposal to include the options discussed in the 10/16/07 f2f meeting [on Virginia Smith - due 2007-10-23].

<Jim> rrsagent

bug 4684 - http://www.w3.org/Bugs/Public/show_bug.cgi?id=4684

Kirk: thinks there are usecases where we want to access xs:key and unique from sml:keyref

Kirk's proposal : http://lists.w3.org/Archives/Public/public-sml/2007Oct/0083.html

Kirk: investigated what needs to be added to the SML spec in order to allow such usecases

Kirk decsribes the proposal

Kirk to describe the proposal using a sample - on the board

Kirk: Kumar raised issues with overlapping symbol spaces for key and keyrefs between xsd and SML
... bug 5130 addresses constraint symbol space: 'clarify the extent of SML constraint symbol space '

<sml:keyref name="CoursesStudent" refer="xxx:StudentIDisKey" scope="tns:students">

<sml:selector xpath="course/student"/>

<sml:field xpath="ID"/>

</sml:keyref>

Kirk: scope="tns:students" is the element in the current complex type where SML reference to Students is defined
... name=".." and refer=".." is standard

Pratul: asks for group opinion on this proposal

John: is key and keyref actually used in existing documents ?

MSM: there is a large collection of schemas over the net using key and keyref

Kumar: thisnks that the underlying need is to refer to existing data; you should not be required to update that data in order to make this happen
... agree with the motivation but feels that schema already provides this by using xs key and unique
... I think the initial intent was to have sml:key and sml:keyref defined as close as possible to the xsd counterparts; feels that this proposal moves away from the original intent

MSM: thinks that the arguments in favor is that offers clarity and simplicity; cons: overlapping symbol spaces, SML implementations will require to understand xsd key and keyref

Kirk: with the current spec content, sml keyref cannot use existing keys if defined using xml schema

Sandy: no strong opinion; feels like something nice to have and with no other consequences, simple to define and implement

Resolution: xml schema key and unique should be separated from the SML key; make this more explicit in the SML spec

5130 will be looked at later

Sandy: 4115 http://www.w3.org/Bugs/Public/show_bug.cgi?id=4995 seems related to this and is covered by the current bug discussion

Pratul: let's look at 4995 later

bug 4977 http://www.w3.org/Bugs/Public/show_bug.cgi?id=4977

Ginny: the spec defines schematron query binding attribute to be some value that is not even defined in the schematron spec
... is it a good reason to restrict this query binding ?

Pratul: proposes to go with the schematron default query binding which is xslt; this should be the floor
... this statement should go in SML, not SMLIF

Resolution: consensus to fix it as mentioned above

bug 5130 http://www.w3.org/Bugs/Public/show_bug.cgi?id=5130

Kumar: for a given target namespace you can't have two constraints with the same name

MSM: trying to understand what this means in conflicting schemas scenario
... I can't have these constrainsts with the same name and result in a valid model

Kumar: but we are going to handle the conflicting case in a separate proposal

Resolution: consensus on proposal, update to editorial

bug 4637 http://www.w3.org/Bugs/Public/show_bug.cgi?id=4637

Kirk: requires to talk about this tomorrow as there is an ongoing off line discussion that may clarify this

bug 4638 http://www.w3.org/Bugs/Public/show_bug.cgi?id=4638

Ginny: conformance section added to the IF document; want to have something similar in the SML spec
... something has been added to the SML spec but there are some changes reuiqred based on feedback
... the document is still changing; want to wait on this section until the document content is more stable

Resolution: agreement to wait on this

bug 4643 http://www.w3.org/Bugs/Public/show_bug.cgi?id=4643

Kumar: doesn't understand the original comments

MSM: tries to remember what he meant

Sandy: comment 1 says that the quoted text is incorrect

<MSM> Proposal: as suggested by comment #2 on 4643, send communication to XML Schema suggesting that they may wish to impose constraints analogous to those of SML, in the interests of (a) alignment and (b) doing the right thing

<scribe> ACTION: Pratul write a proposal to to XML Schema group to address the issue decsribed in 4643 [recorded in http://www.w3.org/2007/10/16-sml-minutes.html#action05]

<trackbot-ng> Created ACTION-137 - Write a proposal to to XML Schema group to address the issue decsribed in 4643 [on Pratul Dublish - due 2007-10-23].

Pratul: resolve this wontfix or works for me

John: suggest to mark it wontfix

Ginny: 4643 blocks 5063

Topic: bug http://www.w3.org/Bugs/Public/show_bug.cgi?id=4658

Pratul: mark this as editorial as it's covered by Sandy's reference proposal

bug http://www.w3.org/Bugs/Public/show_bug.cgi?id=4675

Pratul: we had a similar discussion yesterday about what producers and consumers should be required

Ginny: not sure if we agreed on something

Pratul: we agreed that consumers MUST support uri scheme; producers are not required to support it

Ginny: we talked about this yesterday, related to bug 5121 but I don't think we reached agreement
... assumed that IF constraints both consumers and producers to support uri scheme
... would like to see this unchanged

MSM: is the requirement on a producer to support the uri scheme a testable requirement ?

Pratul: thinks it is
... the test would be that a consumer that understand only sml:uri can take a document and understand it; the doc can go through a round trip exchange and give the same results

Ginny: a level 1 conformant producer supports all IF scheme minus sml uri scheme
... level 2 consumers will also support sml uri scheme

Pratul: why do we need these 2 levels ?

Ginny: so that consumers that understand different schemes can claim conformance at some level

MSM: thinks is useful to use terms for documents to define level of conformance

Resolution: both consumers and producers are required to support sml uri scheme; a producer should be able to produce IF using sml uri scheme; define 2 levels of conformance for the IF documents; mark the defect editorial

bug http://www.w3.org/Bugs/Public/show_bug.cgi?id=4683

Pratul: this seems to be done, covered by Sandy's reference proposal

MSM: what is the answer here ? 0 or more ?

Sandy: the answer is 0 or 1

Resolution: mark this editorial, covered by the ref proposal http://lists.w3.org/Archives/Public/public-sml/2007Sep/0268.html

bug http://www.w3.org/Bugs/Public/show_bug.cgi?id=4687

Kirk: why are we talking about DTD's ?

MSM: this is DTD's for documents in the model we may want to inline

Kirk: but there is some statement, could not find now, that states XML Schema is the schema to use

MSM: possibility that somebody chooses to use entity references for special characters, there is nothing to prevent you using a DTD defining it and XML Schema for the language
... another posibility is that some people really want to use DTD and not XML Schema ( old documents, etc )
... to draft something as a proposal

bug http://www.w3.org/Bugs/Public/show_bug.cgi?id=4739

Ginny: this defect is dependent on 4978
... propose to mark this dependant to 4978

MSM: remarks that it refers to a section that doesn't exist anymore

Ginny: I think it moved under section 6

Sandy: it is 6.1.4

Pratul: looks like a MUST

Resolution: resolve this to MUST and refer to whether to keep err in 4978; mark edittorial

bug http://www.w3.org/Bugs/Public/show_bug.cgi?id=4801

MSM: this is the one reported by MSM
... does not recall the details

Sandy: feels that this is redundant

Resolution: completely remove this section
... remove bullet number 3 only

in addition, a similar section should go under the conformance criteria; on the sentence before the bullet change ref from 3.11.2 to 3.11

bug http://www.w3.org/Bugs/Public/show_bug.cgi?id=4819

Pratul: we agreed to make the change in IF so that a new scheme defines if it is or not an IF scheme

Resolution: remove last sentence

move second sentence of the third paragraph to the addresing scheme definition

reword first sentence to say it is not an IF scheme because of the scheme's definition

<johnarwe> last sentence (of 3.4.2, to be removed) is: SML-IF Consumers MUST NOT interpret wsa:address content as inter-document references.

<johnarwe> sandy: do we need to deal with sml:uri for similar reasons in "SML-IF Consumers MUST interpret xsi:schemaLocation hints and sml:uri content used as SML reference schemes as inter-document references."

<johnarwe> proposal: remove "and sml:uri content used as SML reference schemes "

<johnarwe> resolution: consensus on proposed

<johnarwe> MSM raises 2 related questions

<johnarwe> 1. should we have said xsi:schemaLocation, since the xsi says instances only not xsds

<johnarwe> 2. do we need or want to distinguish between schemalocation in instances vs xsds

<johnarwe> update 4774 to handle #2 above

<Val> bug http://www.w3.org/Bugs/Public/show_bug.cgi?id=4823

bug http://www.w3.org/Bugs/Public/show_bug.cgi?id=4823

Sandy: propose to mark this as a dup of 5117

Resolution: agreed to close as dup of 5117

bug http://www.w3.org/Bugs/Public/show_bug.cgi?id=4865

Pratul: I think this is done, covered by Sandy's ref proposal

Resolution: mark editorial, fix as per Sandy's proposal

ref proposal http://lists.w3.org/Archives/Public/public-sml/2007Sep/0268.html

bug http://www.w3.org/Bugs/Public/show_bug.cgi?id=4872

Pratul: looks done

Kumar: so this should be dup of 4616

John: 4616 is not the right nb, is 4636

Resolution: dup of 4636

bug http://www.w3.org/Bugs/Public/show_bug.cgi?id=4992

Jim: do we try to agree on object identity when using different schemes ?

Sandy: another case is when you have one scheme but multiple targets

Ginny: so when you get back 3 things you need to check if they represent the same object

Sandy: this is not about deref, it's about object validation

MSM: XPath can tell you the identity of object references but only if it refers to the same document
... need a way to identify that schemes are refering to the same document
... proposes to say that if two URI's are equal based on rfc spec, then they refer to the same document

John: proposes to use document aliases as part of the equality test

Jim: is the intend to say that if you are a conforming consumer than you have to be able to decide if two URI's are the same ?

MSM: no; we say that two expressions can evaluate to the same thing
... for documents we have the same story using URI
... for elements, we first establish they are in the same document; after that establish that the two XPath expressions evaluate to the same element

Jim: how do we test for compliant consumers based on these equivalence definitions ?

MSM: we need to specify when you are required to know two documents are the same

Jim: feels that there is disagreement at a fundamental level so doesn't want to stop here

Sandy: proposes to use this approach : if(cond1) then return equal; else if(cond2) then return not equal; else if (impl defined) else - if(true) - or -else return not equal-
... what we should say : if you can't say they are different then you can't say they are the same; this is what Sandy had proposed in bugzilla

Kumar: somebody should come with a proposal

Sandy: I already have a proposal, as decribed by the if(cond1) approach above

John: I don't think we can get over this until we specify what cond1 and cond2 are

Sandy: cond1=string comparison for URI ( assuming they have one)
... before we move to cond2, any suggestions on a better cond1 ?

MSM: rfc gives you several additional steps

Sandy: we use string comparison for IF so we should be consistent

MSM: okay, makes sense

Sandy: cond2=deep compare; (tree comparison, if anything in the tree is different than they are different)
... tricky if you return two elements that look the same; in infoset there is no way to say if they are different
... example on the tricky part : <p> <c/> <c/> </p>

Kumar: propose to make everything starting with cond2 implementation dependant since it may be expensive to do this deep compare

John: not wise since conformance is not meaningful

Kumar: then we'll have a spec with no implemetation

MSM: we aim for a meaningful spec

Summary of Action Items

[NEW] ACTION: Ginny to update acyclic proposal to include the options discussed in the 10/16/07 f2f meeting [recorded in http://www.w3.org/2007/10/16-sml-minutes.html#action03]
[NEW] ACTION: Kumar to investigate if there any implemetation issues with supporting xpath1() scheme [recorded in http://www.w3.org/2007/10/16-sml-minutes.html#action02]
[NEW] ACTION: Kumar toreview 5171 with Sandy and come back with a proposal [recorded in http://www.w3.org/2007/10/16-sml-minutes.html#action01]
[NEW] ACTION: Pratul write a proposal to to XML Schema group to address the issue decsribed in 4643 [recorded in http://www.w3.org/2007/10/16-sml-minutes.html#action05]
[NEW] ACTION: Virginia update acyclic proposal to include the options discussed in the 10/16/07 f2f meeting [recorded in http://www.w3.org/2007/10/16-sml-minutes.html#action04]
 
[End of minutes]

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$Date: 2007/02/23 21:38:13 $