UPDATE: Building XML from XPATHS in XSLT 2.0

Hi guys,

/ 'Michael Kay' says:
> You presumably mean "build an XML document for which none
> of these XPath expressions returns an empty sequence."

Yes, this is exactly what I mean!!

/ 'Michael Kay' says:
> You say "any valid XPath". Are you restricting this to path expressions?
> Absolute path expressions? Are they always evaluated with the root as the
> context node?

I suppose I will have to use Absolute path and start with simple XPATH then
try to deal with more complex examples later... I do not envisage the XPATHS
will ever create invalid XML like in the /a /b example so it isn't important
(just it might be nice to also add some error checking later if I get time!)

I am still wondering whether full XPATH tokenisation will be possible in
XSLT 2.0? And, also how I merge multiple xml fragents as I create single XML
fragments from each path. I have roughly outlined a start of some code
(probably pretty erroneus and missing a lot of detail at this point!!)

XPATH.xml

<?xml version="1.0" encoding="UTF-8"?>
<frame>
 <block
XPATH="/ClinicalDocument/recordTarget/patientRole/patientPatient/name/family
"/>
 <block
XPATH="/ClinicalDocument/recordTarget/patientRole/patientPatient/name/given"
/>
 <block
XPATH="/ClinicalDocument/component/bodyChoice/StructuredBody/component/bodyC
hoice/StructuredBody/component/section/component/section/entry/entryChoice/O
bservation/value"/>
 <block
XPATH="/ClinicalDocument/component/bodyChoice/StructuredBody/component/bodyC
hoice/StructuredBody/component/section[@title=$section-name]/component/secti
on[@title=$subsection-name]/entry/entryChoice/Observation/participant/partic
ipatingEntity/associatedPerson/name"/>
 <block
XPATH="/ClinicalDocument/component/bodyChoice/StructuredBody/component/bodyC
hoice/StructuredBody/component/section/component/section/entry/entryChoice/O
bservation/value"/>
</frame>


XPATH.xsl

<xsl:stylesheet version="2.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output method="xml" encoding="ISO-8859-1" indent="yes"/>
    <!--+
        |     INITIAL INVOCATION
        +-->
    <xsl:template match="/">
        <xsl:apply-templates/>
    </xsl:template>
    <!--+
        |     TEMPLATE TO STEP THROUGH EACH XPATH AND MAKE NEW ADDITIONS
        +-->
    <xsl:template match="block">
        <xsl:param name="xml-fragment"/>
        <xsl:variable name="current-xml-build">
            <xsl:call-template name="merge-xml-structures">
                <xsl:with-param name="xml-fragment" select="$xml-fragment"/>
                <xsl:with-param name="xml-fragment-2">
                    <xsl:call-template name="build-xml-from-path"/>
                </xsl:with-param>
            </xsl:call-template>
        </xsl:variable>
        <xsl:apply-templates select="following-sibling::block[1]">
            <xsl:with-param name="xml-fragment"
select="$current-xml-build"/>
        </xsl:apply-templates>
        <xsl:if test="last()">
            <xsl:copy-of select="$current-xml-build"/>
        </xsl:if>
    </xsl:template>
    <!--+
        |     TEMPLATE TO BUILD SOME XML FROM A SINGLE XPATH
        +-->
    <xsl:template name="build-xml-from-path">
        <xsl:variable name="tokenizedXPATH" select="tokenize(@XPATH,'/')"/>
        <xsl:for-each select="$tokenizedXPATH">
            <!-- in progress -->
        </xsl:for-each>
    </xsl:template>
    <!--+
        |     TEMPLATE TO BUILD SOME XML FROM A SINGLE XPATH
        +-->
    <xsl:template name="merge-xml-structures">
        <xsl:param name="xml-fragment"/>
            <!-- in progress -->
    </xsl:template>
</xsl:stylesheet>


Many Thanks in Advance for any suggestions,

Gary




-----Original Message-----
From: Michael Kay [mailto:mhk@xxxxxxxxx]
Sent: 26 April 2004 22:36
To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
Subject: RE:  Building XML from XPATHS in XSLT 2.0


Some thoughts to help you specify the problem more precisely:

You presumably mean "build an XML document for which none of these XPath
expressions returns an empty sequence."

You say "any valid XPath". Are you restricting this to path expressions?
Absolute path expressions? Are they always evaluated with the root as the
context node?

In general of course there may be no solution. For example if you have two
paths /a and /b there is no document that gives a non-empty answer for both.

Michael Kay

> -----Original Message-----
> From: gary@xxxxxxxxxxx [mailto:gary@xxxxxxxxxxx]
> Sent: 26 April 2004 20:51
> To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
> Subject:  Building XML from XPATHS in XSLT 2.0
>
> Hi Guys,
>
> I have just started working on a problem which is quite
> interesting. I have
> some xml that can contain any valid XPATH as an attribute
> string and I would
> like to go through all the XPATHS listed and build some XML
> based on them.
> i.e.
>
> <frame>
>  <block
> XPATH="/ClinicalDocument/recordTarget/patientRole/patientPatie
> nt/name/family
> "/>
>  <block
> XPATH="/ClinicalDocument/recordTarget/patientRole/patientPatie
> nt/name/given"
> />
>  <block
> XPATH="/ClinicalDocument/component/bodyChoice/StructuredBody/c
> omponent/bodyC
> hoice/StructuredBody/component/section/component/section/entry
> /entryChoice/O
> bservation/value"/>
>  <block
> XPATH="/ClinicalDocument/component/bodyChoice/StructuredBody/c
> omponent/bodyC
> hoice/StructuredBody/component/section[@title=$section-name]/c
> omponent/secti
> on[@title=$subsection-name]/entry/entryChoice/Observation/part
> icipant/partic
> ipatingEntity/associatedPerson/name"/>
>  <block
> XPATH="/ClinicalDocument/component/bodyChoice/StructuredBody/c
> omponent/bodyC
> hoice/StructuredBody/component/section/component/section/entry
> /entryChoice/O
> bservation/value"/>
> </frame>
>
> If anyone has already done something similar to this and
> wants to share some
> code it would be appreciated or if anyone is interstested in
> the solution
> let me know and I will post the group back when I have found
> a solution to
> the problem!
>
> Many Thanks
>
> Gary Cornelius