RE: [Updated] XML Schema 1.1 Tutorial

Hi Michael,

See inlined comments. 

> 15 says "defaultAttributes is used to specify a set of
> attributes that apply to every complexType in the schema."
> 
> Not quite.  Like the default open content, the default
> attributes apply to every complex type declared in the
> schema document (unless somehow blocked); when a schema
> is constructed from several schema documents, there is
> no guarantee that all complex types will have the same
> default attributes.  You say this explicitly in slides
> 162 and 163.


I changed it to this:

    defaultAttributes is used to specify a set 
    of attributes that apply to every complexType 
    in a schema document.

I changed "the schema." to "a schema document."

How's that?

 
> I think that here and elsewhere you are sometimes just
> conflating 'schema' (a set of components, acquired who
> knows how) and 'schema document' (a description in XML
> of a set of components).

Yes, I'm trying to be more careful about that.


> 21:  the example is legal, I think (I have not attempted
> to check it systematically), but it would be more
> natural to specify the wildcard with maxOccurs="unbounded",
> don't you think?  As declared, the type of Book will
> allow at most one element in the instance, other than
> those listed explicitly.  I suspect most people who want
> to use wildcards in all-groups want to allow arbitrarily
> many.


Good. I made the change.

 
> 29 speaks of "the recently adopted IEEE 754-2008 standard
> for floating point decimal", but in fact 754-2008, like
> earlier versions of IEEE 754, also defines floating-point
> binary formats.  I think you might better say that
> precisionDecimal provides support for the floating-point
> decimal formats defined in the recently adopted IEEE
> 754-2008 IEEE Standard for Floating-Point Arithmetic.

Okay. I made the change.
 
> 104 uses the term 'default type' for what the spec calls
> the 'declared type'; there's no law saying you have to use
> the same terminology as the spec, but this particular
> deviation may cause confusion, since the spec does define
> a 'default type', which is given by a final 'alternative'
> element lacking any 'test' attribute.  All type
> alternatives including the default type must be
> validly substitutable for the declared type, but it is
> not required that the other alternatives be substitutable
> for the default type.


I changed it to this:

   The type specified in <alternative> must 
   derive from the element's declared type. 

Better?

 
> 108 shows an xsd:alternative element with an inline
> simple type definition.  This is not strictly speaking
> illegal or impossible, but since the element in question
> is being handled with conditional type assignment it will
> typically have attributes, and if it has any attributes,
> it won't be legal against any simple type.  So a
> simple type will be a possible alternative type only
> when the tests are rather unusual.  The use of a simple
> type is most plausible if all the tests relate to some
> inherited attribute.

I couldn't locate a slide with an xsd:alternative element with an inlines simple type definition. 

 
> 178 says "XML Schema 1.1 supports non-deterministic content
> models!" Given a definition of non-determinism based on
> XSD 1.0, this is true as far as it goes, though it
> looks as if it's saying that 1.1 accepts all non-deterministic
> models, which is not so.  There are two ways to phrase
> it that I think would be more precise and still clear:
> (1) XSD 1.1 allows certain classes of non-deterministic
> content models prohibited by XSD 1.0.  Or (2) XSD 1.1
> refines the rules for content-model determinism to
> allow competition between element particles and wildcard
> paticles; element wins.


Good. I changed it to suggestion (1).


> 264 uses the 1.0 type hierarchy; you might want to use the
> 1.1 diagram.  It can be found at the beginning of section
> 3 of datatypes:
> 
>    http://www.w3.org/TR/xmlschema11-2/#built-in-datatypes
> 
> The SVG is at
> 
>    http://www.w3.org/TR/xmlschema11-2/type-hierarchy-200901.svg
> 
> and there is a fall-back at
> 
>    http://www.w3.org/TR/xmlschema11-2/type-hierarchy-200901.png


I've replaced the old diagram with the new one.

 
> I hope these comments are useful.


Very much so! Thanks Michael!

I've made the changes and uploaded the new version.

/Roger

Received on Thursday, 30 July 2009 12:33:10 UTC