Hi Martin,

Thank you for your comments.
See my remarks below.

----- Original Message ----- 
From: "Martin Honnen" <mahotrash@y...>
Newsgroups: microsoft.public.xml
Sent: Sunday, April 03, 2005 6:45 PM
Subject: Re: newbie xml xsd modelling problem


>
>
> Tis Veugen wrote:
>
>
>> I have a modelling problem that I would like to make clear with these 
>> xml-file and xsd-file.
>>
>> The xsd-file:
>>
>> <xsd:simpleType name="st1">
>>   <xsd:restriction base="xsd:NMTOKEN">
>>     <xsd:enumeration value="v1"/>
>>     <xsd:enumeration value="v2"/>
>>     <xsd:enumeration value="v3"/>
>>   </xsd:restriction>
>> </xsd:simpleType>
>>
>> <xsd:complexType name="ct1">
>>   <xsd:choice>
>>     <xsd:sequence>
>>       <xsd:attribute name="type" type="st1" fixed="v1"/>
>>       <xsd:element name="str" type="string"/>
>
> Have you actually tried to use that schema with a validating XML parser or 
> a schema parser? It would tell you that the xsd:attribute is not allowed 
> inside of the xsd:sequence.

The XRay XML Editor does not complain about it.
According to my book , XML Developer's Guide, it's allowed.
Otherwise, how could such a choice of 3 possibilities regarding attributes 
be modelled?

>>     </xsd:sequence>
>>     <xsd:sequence>
>>       <xsd:element name="str" type="string"/>
>>     </xsd:sequence>
>>     <xsd:sequence>
>>       <xsd:attribute name="type" type="st1"/>
>
> Same here.
>
>
>> The xml-file:
>>
>> <my_ct type="v1">
>>   <str> my other data </str>
>> </my_ct>
>>
>> <my_ct>
>>   <str> my data </str>
>> </my_ct>
>>
>> <my_ct type="v2">
>> </my_ct>
>>
>> <my_ct type="v3">
>> </my_ct>
>>
>> PROBLEM:
>> How to prevent that the following lines would be allowed, according to 
>> the 3rd choice :
>> <my_ct type="v1">
>> </my_ct>
>> So, how should the xsd file look like?
>
> An W3C XML schema doesn't allow you to constraint the element content 
> structure based on an attribute value.
> With a Schematron schema you can model such constraints as you simply 
> express them using XPath expressions:
>  <http://xml.ascc.net/resource/schematron/schematron.html>

Well, for a newbie it's already difficult enough browsing through all this 
new stuff.
And so, I'm hesitating to learn yet another standard.
Therefore, I was looking for an XSD solution.

> -- 
>
> Martin Honnen --- MVP XML
> http://JavaScript.FAQTs.com/