Traversing XSD

[MMA]

Hi there,
Is there a way to traverse an XSD using XPath. My research indicates no
conventional way of doing it, but I was wondering if there was a work around.
Thanks for your help and time.

[Martin Honnen]

MMA wrote:

Is there a way to traverse an XSD using XPath. My research indicates no
conventional way of doing it, but I was wondering if there was a work around.

XSD is XML with namespaces so using XPath on an XSD document is
possible. If you need help with a particular XPath then let us know
details of the schema.

..NET also provides an XML Schema Object Model (SOM) which allows you to
extract type/element/attribute definitions of the schema in a structured
way, see
<http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cpconxsdschemaobjectmodelsom.asp>
--

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

[dickster]

I'm not fully sure what you mean by traverse.

However, XML Schema is written in xml (intentionally) so you can
certainly evaluate XPath expressions against it:

eg.
<?xml version="1.0" encoding="ISO-8859-1"?>
<xsd:schema xmlns="http://Dickster.com"
xmlns:xsd="http://www.w3.org/2001/XMLSchema" ="http://Dickster.com">

<xsd:element name="person">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="firstname" type="xsd:string"/>
<xsd:element name="surname" type="xsd:string"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
</xsd:schema>

e.g.
The XPath expression //xsd:element[@name='surname'] returns the
xsd:element node which has an attribute called 'name' set to
'surname'

[dickster]

XML Schema is written in xml (intentionally)
Therefore you can certainly evaluate XPath expressions against it:

eg.

<xsd:schema xmlns="http://Dickster.com"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
targetNamespace="http://Dickster.com">

<xsd:element name="person">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="firstname" type="xsd:string"/>
<xsd:element name="surname" type="xsd:string"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
</xsd:schema>

e.g.
The XPath expression //xsd:element[@name='surname'] returns the
xsd:element node which has an attribute called 'name' set to
'surname'

[MMA]

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:MIM="http://Dallas.Kodak.com/2005/Schema/MIMCORE"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:ns2="http://www.w3.org/1999/xhtml"
xmlns:hfp="http://www.w3.org/2001/XMLSchema-hasFacetAndProperty"
xmlns:DICOM="http://Dallas.Kodak.com/2005/Schema/DICOM-in-XML"
targetNamespace="http://Dallas.Kodak.com/2005/Schema/MIMCORE"
version="2006Jan6">
<xs:element name="DeliveryJob">
<xs:complexType>
<xs:attribute name="version" type="xs:token" fixed="2006Feb23"
use="required" />
</xs:complexType>
</xs:element>
</xs:schema>

This is the XSD I am trying to navigate through and I am trying to access
the xs:attribute node to get the value of the name attribut. Dickester thanks
for your sample XPath query, do you think //xs:attribute/@name would work?

Thanks for your time and help
MMA

"dickster" wrote:

I'm not fully sure what you mean by traverse.

However, XML Schema is written in xml (intentionally) so you can
certainly evaluate XPath expressions against it:

eg.
<?xml version="1.0" encoding="ISO-8859-1"?>
<xsd:schema xmlns="http://Dickster.com"
xmlns:xsd="http://www.w3.org/2001/XMLSchema" ="http://Dickster.com">

<xsd:element name="person">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="firstname" type="xsd:string"/>
<xsd:element name="surname" type="xsd:string"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
</xsd:schema>

e.g.
The XPath expression //xsd:element[@name='surname'] returns the
xsd:element node which has an attribute called 'name' set to
'surname'

[dickster]

When an XPath Expression is evaluated, it can return an object of one
of four types:
node-set
boolean
number
string

The return type of your xpath I believe is "string"

This XPath expression will search through the entire XML (i.e your XSD)
due to the "//" & return each matching string

So in english what I believe your Xpath will do is return the "value"
of each "name" attribute contained within an xs:attribute node

In your case this returns the string: "version"

For playing around with Xpath I cheat - Altova XMLSpy has a handy Xpath
evaluator

Hopefully someone will correct if what I have said is wrong.

[Cerebrus]

Hi,

do you think //xs:attribute/@name would work?

Yes, it would. Try it and see ! It would return "version"

Regards,

Cerebrus.

[dickster]

A Question

Assuming MMA's xsd was

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:MIM="http://Dallas.Kodak.com/2005/Schema/MIMCORE"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:ns2="http://www.w3.org/1999/xhtml"
xmlns:hfp="http://www.w3.org/2001/XMLSchema-hasFacetAndProperty"
xmlns:DICOM="http://Dallas.Kodak.com/2005/Schema/DICOM-in-XML"
targetNamespace="http://Dallas.Kodak.com/2005/Schema/MIMCORE"
version="2006Jan6">
<xs:element name="DeliveryJob">
<xs:complexType>
<xs:attribute name="version" type="xs:token" fixed="2006Feb23"
use="required">yyy</xs:attribute>
<xs:attribute name="Dickster"/>
</xs:complexType>
</xs:element>
</xs:schema>

would we say the Xpath expression "//xs:attribute/@name" returns

1. a string
2. a set of strings
3. a nodeset
4. other

Dickster

[Martin Honnen]

dickster wrote:

would we say the Xpath expression "//xs:attribute/@name" returns

1. a string
2. a set of strings
3. a nodeset
4. other

It selects a node set.

--

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

[dickster]

had there just been one

<xs:attribute name="

node in the xml would the return have been "string" or "nodeset" again.

-----

obviously an xpath like: concat('George', ' ','Best') returns "string"

[Martin Honnen]

dickster wrote:

had there just been one

<xs:attribute name="

node in the xml would the return have been "string" or "nodeset" again.

It does not depend on the XML document what result type the XPath
expression has, that XPath expression
//xs:attribute/@name
selects a node set. Whether that node set is empty or contains one or
more attribute nodes depends on the XML document.
--

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

[dickster]

Thanks Martin

Dickster