Just for sports, an XSLT 1.0 version (mis)using string manipulation:
<?xml version="1.0"?>
<stylesheet xmlns="http://www.w3.org/1999/XSL/Transform"; version="1.0">
<output method="text"/>
<key name="sec-by-id" match="Section" use="@id"/>
<param name="search" select="'A'"/>
<template match="Include">
<param name="found-sections"/>
<if test="not(contains($found-sections,concat(' ',@idref,' ')))">
<value-of select="concat(@idref,' ')"/>
<apply-templates select="key('sec-by-id',@idref)/Include">
<with-param name="found-sections"
select="concat($found-sections,@id,' ')"/>
</apply-templates>
</if>
</template>
<template name="sort-out-duplicates">
<!-- $space-separated-items has space after every item, like "A B C D " -->
<param name="space-separated-items"/>
<variable name="first-item"
select="substring-before($space-separated-items,' ')"/>
<!-- $remaining-items has leading space and space after every
item, like " B C D " -->
<variable name="remaining-items"
select="substring-after($space-separated-items,$first-item)"/>
<if test="not(contains($remaining-items,concat(' ',$first-item,' ')))">
<value-of select="$first-item"/>
<if test="$remaining-items != ' '">
<value-of select="', '"/>
</if>
</if>
<if test="$remaining-items != ' '">
<call-template name="sort-out-duplicates">
<with-param name="space-separated-items"
select="substring($remaining-items,2)"/>
</call-template>
</if>
</template>
<template match="/">
<variable name="ids-with-duplicates">
<value-of select="concat($search,' ')"/>
<apply-templates select="key('sec-by-id',$search)/Include">
<with-param name="found-sections" select="concat(' ',$search,' ')"/>
</apply-templates>
</variable>
<call-template name="sort-out-duplicates">
<with-param name="space-separated-items" select="$ids-with-duplicates"/>
</call-template>
</template>
</stylesheet>
2011/10/8 Martin Honnen <Martin(_dot_)Honnen(_at_)gmx(_dot_)de>:
Costello, Roger L. wrote:
I have a Document consisting of a bunch of Sections. Each Section has a
unique identifier. Each Section may reference other Sections via an Include
element, e.g.,
<Document>
<Section id="A">
<Include idref="B" />
<Include idref="C" />
</Section>
<Section id="B">
<Include idref="D" />
</Section>
<Section id="C">
<Include idref="D" />
</Section>
<Section id="D">
<Include idref="A" />
</Section>
<Section id="E" />
</Document>
Problem: Write a function and pass a Section to it. The function outputs
the Section and all the Sections it Includes and all the Sections each of
them Includes, and so on.
Be sure there are no duplicates in the output.
Do you want a particular output order?
Example: invoke the function with Section A. Here's the output:
A, B, C, D
Is there an elegant XSLT implementation of this graph traversal problem?
With XSLT 2.0 I have tried
<xsl:stylesheet
xmlns:xsl="http://www.w3.org/1999/XSL/Transform";
xmlns:xs="http://www.w3.org/2001/XMLSchema";
xmlns:mf="http://example.com/mf";
version="2.0"
exclude-result-prefixes="xs mf">
<xsl:param name="search" as="xs:string" select="'A'"/>
<xsl:output method="text"/>
<xsl:key name="sec-by-id" match="Section" use="@id"/>
<xsl:function name="mf:find-sections" as="element(Section)+">
<xsl:param name="start" as="element(Section)"/>
<xsl:param name="found" as="element(Section)+"/>
<xsl:variable name="includes" as="element(Section)*"
select="key('sec-by-id', $start/Include/@idref, root($start))"/>
<xsl:sequence select="$start | ($includes except
$found)/mf:find-sections(., . | $found)"/>
</xsl:function>
<xsl:template match="/">
<xsl:variable name="start" as="element(Section)" select="key('sec-by-id',
$search)"/>
<xsl:value-of select="mf:find-sections($start, $start)/@id" separator=",
"/>
</xsl:template>
</xsl:stylesheet>
and for your sample input both Saxon 9.3 as well as AltovaXML output "A, B,
C, D". The stylesheet exploits that the "union" operator "|" eliminates
duplicates. Output order should be input document order that way.
--
Martin Honnen --- MVP Data Platform Development
http://msmvps.com/blogs/martin_honnen/
--~------------------------------------------------------------------
XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list
To unsubscribe, go to: http://lists.mulberrytech.com/xsl-list/
or e-mail:
<mailto:xsl-list-unsubscribe(_at_)lists(_dot_)mulberrytech(_dot_)com>
--~--
--~------------------------------------------------------------------
XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list
To unsubscribe, go to: http://lists.mulberrytech.com/xsl-list/
or e-mail: <mailto:xsl-list-unsubscribe(_at_)lists(_dot_)mulberrytech(_dot_)com>
--~--