Pavel Lepin wrote:
> Philipp <sicsicsic@f...> wrote in
> <1207843345_2873@s...>:
>> I'm learning W3C Schema 1.0 and have encountered a
>> problem. I want to make a complex type which requires to
>> contain exactly 1 instance of each of a list of elements
>> (a, b, c) and at least once a choice of several other
>> elements ( d1 | d2 | d3 ). This in any order.
>>
>> I have come up with the following which is (unfortunately)
>> invalid XSD 1.0: <complexType name="root">
>>    <all>
>>      <element name="a" type="string"></element>
>>      <element name="b" type="string"></element>
>>      <element name="c" type="string"></element>
>>      <choice maxOccurs="unbounded" minOccurs="1">
>>        <element name="d1" type="string"></element>
>>        <element name="d2" type="string"></element>
>>        <element name="d3" type="string"></element>
>>      </choice>
>>    </all>
>> </complexType>
> 
> W3C's schema definition language was not designed for
> defining arbitrarily complex grammars. If your document
> format is well-structured, expressing it in XML Schema
> should be easy. If it's not, try using a more powerful
> schema definition language or check validity on the
> application side.
> 

After some reading on the web, I think my biggest problem is that my 
elements are non-ordered. This makes sense for me both from the model 
perspective (I don't care if eg. my Book object sets the Author or the 
Title first) as well as from my implementation perspective (these values 
are marshalled from a java Properties object which does not guaratee a 
constant traversal order for its iterator.

Hopefully Xerces for Schema 1.1 will soon be available :-) (and also 
that Schema 1.1 fixes these shortcommings)

Phil