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Bug 4686 - Use schema terminorlogies to describe "xml schema valid"
Summary: Use schema terminorlogies to describe "xml schema valid"
Alias: None
Product: SML
Classification: Unclassified
Component: Core+Interchange Format (show other bugs)
Version: unspecified
Hardware: PC Windows XP
: P1 normal
Target Milestone: Second draft
Assignee: Virginia Smith
QA Contact: SML Working Group discussion list
Depends on:
Reported: 2007-06-21 17:44 UTC by Sandy Gao
Modified: 2007-09-20 20:25 UTC (History)
0 users

See Also:


Description Sandy Gao 2007-06-21 17:44:13 UTC
The "Model Validation" section has words like "document MUST be XML Schema valid" or "must be valid under the xml schema". But XML Schema doesn't define what qualifies as XML schema valid.

Schema assessment produces PSVIs, which is the only output. SML needs to describe the expected behavior in terms of PSVI properties/values. There are 2 obvious options.

1. The [validity] PSVI property for the document element must be "valid".

2. The [validity] PSVI property for the document element must be "valid" and there is no descendant information items (element or attribute) whose [validity] is "invalid".

The difference between these 2 options is that if a subtree is laxly assessed and something is marked [validity]=invalid in that subtree, the [validity] of the room is not affected. In this case, option 1 would say it's valid; while option 2 says it's not valid.

Depending on the context, we may want to pick one of these 2 alternatives (or others).

A couple of concrete examples. In the core SML spec, section "Model Validation". It's not obviously which alternative should be used here.

And in the SML-IF spec, section "The Basics", SML-IF documents are required to be valid. Here it seems option #1 is more desirable.
A concrete example SML-IF doc
Comment 1 Valentina Popescu 2007-08-28 16:34:41 UTC
copied from the f2f IRC discussion :

<Jim> Bug 4686 Use schema terminorlogies to describe "xml schema valid" which is not a defined term in the SML Schema spec.
*** pratul [c72bd072@] has joined #sml
<MSM> has an overview that may be useful here.
<Jim> MSM differntiated between the notion of conformance in XML Schema 1.0 vs. 1.1 as follows:
<Jim> 1.0 does not define the term "conformance" for documents.
<Jim> 1.1 defines the "conformance" for SML Schema documents and Instnace documents.
<MSM> no, not for instance documents.  Instance documents do not conform, or fail to conform, to XSDL.
<Jim> John proposed that we agree at an abstract level what we mean by "validity" to accomodate the second draft as it is to be reviewed by the SML Schema WG.
<Jim> We can revisit as needed based on feedback from implementors.
<Jim> Kumar requested that a note be added to the spec to emphaize that this is not a final definition.
<Sandy> <my:root xmlns:...>                         -- valid
<Sandy>   <my:ref sml:ref="true">                   -- valid
<Sandy>     <sml:uri>...</sml:uri>                  -- valid
<Sandy>     <some:element>                          -- notKnown
<Sandy>       <child xsi:type="xs:int>abc</child>   -- invalid
<Sandy>     </some:element>
<Sandy>   </my:ref>
<Sandy> </my:root>
<Jim> Sandy made three proposals:
<Jim> 1. That PSVI properties be exposed and available for use to the users/consumers.
<Jim> 2. That we define our criteria for the boolean value of validity.
<Jim> 3. That the notion of valid vs. invalid does not require any specific behavior by the validator or the process that invokes it.
Comment 2 Valentina Popescu 2007-08-28 16:57:42 UTC
Two options discussed for defining SML schema validity:

- NO invalid anywhere in tree
- No constraints in root element

- NO invalid anywhere in tree
- root element 'valid'

Agreement to go with option A 

Editors to make a change to the 4th bullet in section 6.
What to be changed as recorded by MSM in IRC:

<MSM> proposal for second bullet:  editors to clarify that this means "xs:schema element in each schema document has [validity] = 'valid'"
<MSM> SG alternative for second bullet:  schema document must give rise to a conforming schema (this is a stronger constraint)
Comment 3 Valentina Popescu 2007-08-28 17:06:41 UTC
More comments from IRC

<Jim> Pratul proposed that for bullet 4, we should say something such as:
<Jim> "For each document, validatin must be possible"
<Jim> changed to validation assessment.
<Jim> Wordsmithing to be dnoe by editors.
Comment 4 Virginia Smith 2007-08-30 00:13:41 UTC
Changed keyword to 'editorial' based on new comments.
Comment 5 Virginia Smith 2007-09-06 08:27:30 UTC
Bullet points 2 and 4 changed from:
- Each XML Schema document in the model's definition documents MUST be a valid XML Schema document [XML Schema Datatypes]
- Each document in the model MUST be XML Schema valid with respect to the XML Schema documents in the model's definition document


- Each XML Schema document in the model's definition documents MUST satisfy the conditions expressed in Errors in Schema Construction and Structure (ยง5.1). [XML Schema Structures]
- In each instance document in the model, the [validity] property of the root element and all of its attributes and descendants MUST NOT be "invalid" when schema validity is assessed by a conforming schema-aware processor with respect to the referenced XML Schema documents in the model's definition documents. [XML Schema Structures]
Comment 6 Pratul Dublish 2007-09-17 15:30:45 UTC
Looks good - recommend approval by the WG
Comment 7 Pratul Dublish 2007-09-20 20:25:41 UTC
Resolving as per consensus in 9/20 call