XML Schema problem...

[Andrew]

Antony (4:26 PM) :
Hello all !

I have a problem with XML schema.

My XML document which I need to be validated
can be one of the following two types:

1st type is

<?xml version="1.0"?>
<response>
<msg_id>100</msg_id>
<command>Command1</command>
<time>100</time>
<b>text</b>
</response>
2nd type is

<?xml version="1.0"?>
<response>
<msg_id>100</msg__id>
<command>Command2</command>
<sometag>content</sometag>
<time>789012</time>
<a>text</a>
</response>
Note that content of the "command" element
is used to determine the rest of elements. Thus
"Command1" means that there should be "time" and "b" elements,
and "Command2" means that there should be "sometag", "time", and "a"
elements.

When trying to load the schema both xerces and msxml parsers
return me error message: "Unique Particle Attribution rule".

How should correct schema look ?
Can anyone help ?

Thanks in advance.

[Andrew]

This is my schema:

<?xml version="1.0"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">

<xs:element name="response" type="respType"/>

<xs:complexType name="respType">
<xs:choice>
<xs:group ref="g1"/>
<xs:group ref="g2"/>
</xs:choice>
</xs:complexType>

<xs:group name="g1">
<xs:sequence>
<xs:element name="msg_id" type="xs:int"/>
<xs:element name="command" type="xs:string"/>
<xs:element name="time" type="xs:int"/>
<xs:element name="b" type="xs:string"/>
</xs:sequence>
</xs:group>

<xs:group name="g2">
<xs:sequence>
<xs:element name="msg_id" type="xs:int"/>
<xs:element name="command" type="xs:string"/>
<xs:element name="sometag" type="xs:string"/>
<xs:element name="time" type="xs:int"/>
<xs:element name="a" type="xs:string"/>
</xs:sequence>
</xs:group>

</xs:schema>

[Sean Bright]

Andrew wrote:

Note that content of the "command" element
is used to determine the rest of elements. Thus
"Command1" means that there should be "time" and "b" elements,
and "Command2" means that there should be "sometag", "time", and "a"
elements.

I'm not sure this type of conditional processing is possible with XML
Schemas. See the the following thread in this newsgroup for something
slightly similar:

Message ID: <6a**************************@posting.google.com >
From: Ralf Wahner
Subject: Schema express that "@a present if and only if @b present",
where @a, @b are attributes

The relevant portion of that thread is:

As I'm new to XML Schema I dare to ask a possibly recurring
question: Given an element <elem> with two attributes @a and
@b. The attributes are bound by the condition, that either both
or none must be present, i.e.

That is not possible with W3C's xml schema.

Apparently something like this is possible with RELAX NG, but I wouldn't
know about that.

Hope this helps,
Sean

[strajan]

Please try whether the following work. Just re-arranged a little bit.
=============
<?xml version="1.0" ?>

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">

<xs:element name="response" type="respType" />

<xs:complexType name="respType">

<xs:sequence>

<xs:element name="msg_id" type="xs:int" />

<xs:element name="command" type="xs:string" />

<xs:choice>

<xs:group ref="g1" />

<xs:group ref="g2" />

</xs:choice>

</xs:sequence>

</xs:complexType>

<xs:group name="g1">

<xs:sequence>

<xs:element name="time" type="xs:int" />

<xs:element name="b" type="xs:string" />

</xs:sequence>

</xs:group>

<xs:group name="g2">

<xs:sequence>

<xs:element name="sometag" type="xs:string" />

<xs:element name="time" type="xs:int" />

<xs:element name="a" type="xs:string" />

</xs:sequence>

</xs:group>

</xs:schema>

================

"Andrew" <ch**@million.dp.ua> wrote in message
news:br***********@pandora.alkar.net...

This is my schema:

<?xml version="1.0"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">

<xs:element name="response" type="respType"/>

<xs:complexType name="respType">
<xs:choice>
<xs:group ref="g1"/>
<xs:group ref="g2"/>
</xs:choice>
</xs:complexType>

<xs:group name="g1">
<xs:sequence>
<xs:element name="msg_id" type="xs:int"/>
<xs:element name="command" type="xs:string"/>
<xs:element name="time" type="xs:int"/>
<xs:element name="b" type="xs:string"/>
</xs:sequence>
</xs:group>

<xs:group name="g2">
<xs:sequence>
<xs:element name="msg_id" type="xs:int"/>
<xs:element name="command" type="xs:string"/>
<xs:element name="sometag" type="xs:string"/>
<xs:element name="time" type="xs:int"/>
<xs:element name="a" type="xs:string"/>
</xs:sequence>
</xs:group>

</xs:schema>

[Jakob Møbjerg Nielsen]

Andrew wrote:

<xs:element name="command" type="xs:string"/>
<xs:element name="command" type="xs:string"/>

Sorry about the late answer, but why not create your own types with a
pattern restriction?

Blatantly stolen from http://www.w3.org/TR/xmlschema-2/#rf-pattern:

<simpleType name=command1>
<restriction base='string'>
<pattern value='Command1'/>
</restriction>
</simpleType>

<simpleType name='command2'>
<restriction base='string'>
<pattern value='Command2'/>
</restriction>
</simpleType>

--
Jakob Møbjerg Nielsen | "Nine-tenths of the universe is
th******@dataloger.dk | knowledge of the position and direction
http://www.jakobnielsen.dk/ | of everything in the other tenth."
| -- Terry Pratchett, Thief of Time