RE: [xsl] Xpath/XSLT 2.0 & Schema Question

["Xia Li" <xli@xxxxxxxxxxxxx>]

Hi,

You asked,

[A quick question, when I tried to get the type-name using the fully
namespaced name...

		<xsl:variable name="type-name" select="./@xsi:type"/>

...nothing was returned, why?]

The value of the attribute @xsi:type is a reference to the type. It usually
appears as a qualified name which is prefix + ":" + localname, e.g.
pre:typename.

In your schema, the value of the attribute @name on a type definition only
contains the local name of the type,

 <xsd:complexType name="typename">
   ...
 </xsd:complexType>

So the path expression "$schemas//xsd:complexType[@name = $type-name]" would
result in nothing as the left side of the "=" is a local name "typename" while
the right side is a qualified name "pre:typename".

You could construct a type QName from the qualified name provided by @xsi:type
using the constructor xsd:QName(@xsi:type) and then retrieve the local name
using the function local-name-from-QName().

<!-- construct a type QName from a type lexical QName -->
<xsl:variable name="type-QName" select="xsd:QName(./@xsi:type)"/>

<!-- retrieve the type local name from the type QName -->
<xsl:variable name="type-localname"
select="local-name-from-QName($type-QName)"/>

<!-- use the type local name to match the complex type definition with a name
attribute specifying the type local name-->
<xsl:variable name="schema-obj"
select="$schemas//xsd:complexType[@name = $type-localname]"/>

The alternative is to directly call the function in the library

xsdf:get-global-type-def($type-QName, $schemas), pass the type QName to the
function as the value of the first parameter,

It would return the type definition element with the specified type QName.


Lisa





-----Original Message-----
From: Luke Stedman [mailto:luke.stedman@xxxxxxxxx]
Sent: Friday, April 02, 2010 2:58 AM
To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
Subject: Re: [xsl] Xpath/XSLT 2.0 & Schema Question

Xia,

Thanks, that seems to have done the trick.

	<xsl:variable name="schemas"
select="xsdf:load-schemas-by-URI('schema.xsd')"/>
	...
	<xsl:template match="*[@name]">
		<xsl:variable name="type-name" select="./@*:type"/>
		<xsl:variable name="schema-obj"
select="$schemas//xsd:complexType[@name = $type-name]"/>
		<xsl:variable name="class-name" select="$schema-obj//classes/base"/>
	...

The above works perfectly for what I want to achieve, i.e. get the
base class out of the schema.

A quick question, when I tried to get the type-name using the fully
namespaced name...

		<xsl:variable name="type-name" select="./@xsi:type"/>

...nothing was returned, why?

I am using Saxon 9.2 via .Net.

Michael,

Your comment with regards schema awareness and information being used
by the XSLT processor, what information is used and where/how?

Thanks for your help/pointers.
Luke


On 1 April 2010 17:41, Xia Li <xli@xxxxxxxxxxxxx> wrote:
>
> Hi
>
>        The element test "element(*, $type)" in your code matches an
*instance* element node whose type definition is of $type or derived from
$type. It cannot be used to retrieve the corresponding type definition in your
schema.
>
>        If you need to make use of schema information, you might take a look
at the library here http://www.ibm.com/developerworks/library/x-schemanode/.
There is a function xsdf:get-global-type-def() in the library that can be used
to retrieve the type definition with a given type name from your schema.
>
> Lisa
>
> -----Original Message-----
> From: Luke Stedman [mailto:luke.stedman@xxxxxxxxx]
> Sent: Thursday, April 01, 2010 8:59 AM
> To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
> Subject: [xsl] Xpath/XSLT 2.0 & Schema Question
>
> Apologies in advance for what is probably a very simple/basic/stupid
question.
>
> I have just started using XSL 2.0, having had enough of the
> restrictions of XSL 1.0, and am trying to write a XSL that is schema
> aware.
>
> I would like to process an XML file and add information/process
> something based on the schema, for example adding class information to
> XML output or processing an element in a specific way if we want a
> console script or Python script output.
>
> I have tried for the last couple of hours to get the code working but
> seem to be unable to, a small snippet of code is below...
>
>   <xsl:template match="*[@name and @xsi:type]">
>   <xsl:copy>
>    <xsl:copy-of select="@*"/>
>    <xsl:attribute name="action" select="'new'"/>
>    <xsl:variable name="name" select="name(.)"/>
>    <xsl:variable name="type" select="current()/@xsi:type"/>
>    <xsl:variable name="object" select="element(*, $type)"/> <!-- I
> want to get the relevant schema entry here -->
>    <xsl:message>
>     ++++
>     <xsl:value-of select="current()/@name"/>
>     <xsl:variable name="type" select="current()/@xsi:type"/>
>     <xsl:value-of select="$object//base"/>
>     ++++
>    </xsl:message>
>    <xsl:apply-templates/>
>   </xsl:copy>
>  </xsl:template>
>
> Am I misunderstanding the functionality or doing something wrong?
>
> If I have missed a relevant post on the list or obvious link then
> please point me in its direction, I was unable to find one using a
> search.
>
> Apologies again for any stupid comments/expectations.
> Luke