Comparing 2 node sets based on attribute sequence - xslt

Question

I'm trying to build up a kind of library XML, comparing various nodes and combining them for later reuse. The logic should be fairly straightforward, if the tag_XX attribute value sequence of a given language is equal to the tag_YY attribute value sequence of another language, the nodes can be combined. See below XML example
<Book>
<Section>
<GB>
<Para tag_GB="L1">
<Content_GB>string_1</Content_GB>
</Para>
<Para tag_GB="Illanc">
<Content_GB>string_2</Content_GB>
</Para>
<Para tag_GB="|PLB">
<Content_GB>string_3</Content_GB>
</Para>
<Para tag_GB="L1">
<Content_GB>string_4</Content_GB>
</Para>
<Para tag_GB="Sub">
<Content_GB>string_5</Content_GB>
</Para>
<Para tag_GB="L3">
<Content_GB>string_6</Content_GB>
</Para>
<Para tag_GB="Subbull">
<Content_GB>string_7</Content_GB>
</Para>
</GB>
<!-- German translations - OK because same attribute sequence -->
<DE>
<Para tag_DE="L1">
<Content_DE>German_translation of_string_1</Content_DE>
</Para>
<Para tag_DE="Illanc">
<Content_DE>German_translation of_string_2</Content_DE>
</Para>
<Para tag_DE="|PLB">
<Content_DE>German_translation of_string_3</Content_DE>
</Para>
<Para tag_DE="L1">
<Content_DE>German_translation of_string_4</Content_DE>
</Para>
<Para tag_DE="Sub">
<Content_DE>German_translation of_string_5</Content_DE>
</Para>
<Para tag_DE="L3">
<Content_DE>German_translation of_string_6</Content_DE>
</Para>
<Para tag_DE="Subbull">
<Content_DE>German_translation of_string_7</Content_DE>
</Para>
</DE>
<!-- Danish translations - NG because not same attribute sequence -->
<DK>
<Para tag_DK="L1">
<Content_DK>Partial_Danish_translation_of_string_1</Content_DK>
</Para>
<Para tag_DK="L1_sub">
<Content_DK>Partial_Danish_translation_of_string_1</Content_DK>
</Para>
<Para tag_DK="Illanc">
<Content_DK>Danish_translation_of_string_2</Content_DK>
</Para>
<Para tag_DK="L1">
<Content_DK>Danish_translation_of_string_4</Content_DK>
</Para>
<Para tag_DK="|PLB">
<Content_DK>Danish_translation_of_string_3</Content_DK>
</Para>
<Para tag_DK="L3">
<Content_DK>Danish_translation_of_string_6</Content_DK>
</Para>
<Para tag_DK="Sub">
<Content_DK>Danish_translation_of_string_5</Content_DK>
</Para>
<Para tag_DK="Subbull">
<Content_DK>Danish_translation_of_string_7</Content_DK>
</Para>
</DK>
</Section>
</Book>
So
GB tag_GB value sequence = L1 -> Illanc -> ... -> SubBul
DE tag_DE value sequence = L1 -> Illanc -> ... -> SubBul (same as GB so ok)
DK tag_DK value sequence = L1 -> L1.sub -> Oops, expected Illanc meaning this sequence is not the same as GB and locale can be ignored
Since German and English node sets have the same attribute sequence I like to combine them as follows :
<Book>
<Dictionary>
<Para tag="L1">
<Content_GB>string_1</Content_GB>
<Content_DE>German_translation of_string_1</Content_DE>
</Para>
<Para tag="Illanc">
<Content_GB>string_2</Content_GB>
<Content_DE>German_translation of_string_2</Content_DE>
</Para>
<Para tag="|PLB">
<Content_GB>string_3</Content_GB>
<Content_DE>German_translation of_string_3</Content_DE>
</Para>
<Para tag="L1">
<Content_GB>string_4</Content_GB>
<Content_DE>German_translation of_string_4</Content_DE>
</Para>
<Para tag="Sub">
<Content_GB>string_5</Content_GB>
<Content_DE>German_translation of_string_5</Content_DE>
</Para>
<Para tag="L3">
<Content_GB>string_6</Content_GB>
<Content_DE>German_translation of_string_6</Content_DE>
</Para>
<Para tag="Subbull">
<Content_GB>string_7</Content_GB>
<Content_DE>German_translation of_string_7</Content_DE>
</Para>
</Dictionary>
</Book>
The stylesheet I use is the following :
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="xml" version="1.0" xmlns="http://www.w3.org/1999/xhtml" encoding="UTF-8" indent="yes"/>
<xsl:output omit-xml-declaration="yes" indent="yes"/>
<xsl:template match="/">
<xsl:copy>
<xsl:apply-templates select="#* | node()"/>
</xsl:copy>
</xsl:template>
<xsl:template match="#* | node()">
<xsl:copy>
<xsl:apply-templates select="#* | node()"/>
</xsl:copy>
</xsl:template>
<xsl:template match="text()">
<xsl:value-of select="normalize-space(.)"/>
</xsl:template>
<xsl:template match="Section">
<!-- store reference tag list -->
<xsl:variable name="Ref_tagList" select="GB/Para/attribute()[1]"/>
<Dictionary>
<xsl:for-each select="GB/Para">
<xsl:variable name="pos" select="position()"/>
<Para tag="{#tag_GB}">
<!-- Copy English Master -->
<xsl:apply-templates select="element()[1]"/>
<xsl:for-each select="//Book/Section/element()[not(self::GB)]">
<!-- store current locale tag list -->
<xsl:variable name="Curr_tagList" select="Para/attribute()[1]"/>
<xsl:if test="$Ref_tagList = $Curr_tagList">
<!-- Copy current locale is current tag list equals reference tag list -->
<xsl:apply-templates select="Para[position()=$pos]/element()[1]"/>
</xsl:if>
</xsl:for-each>
</Para>
</xsl:for-each>
</Dictionary>
</xsl:template>
</xsl:stylesheet>
Apart from probably not the most efficient way to do this (I'm fairly new to the xslt game...) it's not working either. The logic I had in mind is to take the attribute set of the English master, and if the attribute set of any other locale is equal I copy, if not I ignore. But for some reason also nodesets that have a different attribute sequence are happily copied (as seen in below). Can some one tell me where my logic conflicts with reality ? Thanks in advance !
Current output Including Danish that should have been ignored ...
<Book>
<Dictionary>
<Para tag="L1">
<Content_GB>string_1</Content_GB>
<Content_DE>German_translation of_string_1</Content_DE>
<Content_DK>Partial_Danish_translation_of_string_1</Content_DK>
</Para>
<Para tag="Illanc">
<Content_GB>string_2</Content_GB>
<Content_DE>German_translation of_string_2</Content_DE>
<Content_DK>Partial_Danish_translation_of_string_1</Content_DK>
</Para>
<Para tag="|PLB">
<Content_GB>string_3</Content_GB>
<Content_DE>German_translation of_string_3</Content_DE>
<Content_DK>Danish_translation_of_string_2</Content_DK>
</Para>
<Para tag="L1">
<Content_GB>string_4</Content_GB>
<Content_DE>German_translation of_string_4</Content_DE>
<Content_DK>Danish_translation_of_string_4</Content_DK>
</Para>
<Para tag="Sub">
<Content_GB>string_5</Content_GB>
<Content_DE>German_translation of_string_5</Content_DE>
<Content_DK>Danish_translation_of_string_3</Content_DK>
</Para>
<Para tag="L3">
<Content_GB>string_6</Content_GB>
<Content_DE>German_translation of_string_6</Content_DE>
<Content_DK>Danish_translation_of_string_6</Content_DK>
</Para>
<Para tag="Subbull">
<Content_GB>string_7</Content_GB>
<Content_DE>German_translation of_string_7</Content_DE>
<Content_DK>Danish_translation_of_string_5</Content_DK>
</Para>
</Dictionary>
</Book>

Answer 1

This is might not be the best solution. I've used the following XSLT 2.0 features:
I compared the sequence of attributes using string-join().
I've exploited the possibility of using RTF variables
There are probably more XSLT 2.0 facilities which can resolve your problem. but I think the BIG problem here is your input document.
I'm sorry did not have a look to your current transform. Just implemented one from scratch. Hope it helps:
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output indent="yes"/>
<xsl:strip-space elements="*"/>
<xsl:template match="GB">
<Book>
<Dictionary>
<xsl:variable name="matches">
<xsl:for-each select="following-sibling::*
[string-join(Para/#*,'-')
= string-join(current()/Para/#*,'-')]">
<match><xsl:copy-of select="Para/*"/></match>
</xsl:for-each>
</xsl:variable>
<xsl:apply-templates select="Para">
<xsl:with-param name="matches" select="$matches"/>
</xsl:apply-templates>
</Dictionary>
</Book>
</xsl:template>
<xsl:template match="Para[parent::GB]">
<xsl:param name="matches"/>
<xsl:variable name="pos" select="position()"/>
<Para tag="{#tag_GB}">
<xsl:copy-of select="Content_GB"/>
<xsl:copy-of select="$matches/match/*[position()=$pos]"/>
</Para>
</xsl:template>
<xsl:template match="text()"/>
</xsl:stylesheet>
When applied to the input document provided in the question, the following output is produced:
<Book>
<Dictionary>
<Para tag="L1">
<Content_GB>string_1</Content_GB>
<Content_DE>German_translation of_string_1</Content_DE>
</Para>
<Para tag="Illanc">
<Content_GB>string_2</Content_GB>
<Content_DE>German_translation of_string_2</Content_DE>
</Para>
<Para tag="|PLB">
<Content_GB>string_3</Content_GB>
<Content_DE>German_translation of_string_3</Content_DE>
</Para>
<Para tag="L1">
<Content_GB>string_4</Content_GB>
<Content_DE>German_translation of_string_4</Content_DE>
</Para>
<Para tag="Sub">
<Content_GB>string_5</Content_GB>
<Content_DE>German_translation of_string_5</Content_DE>
</Para>
<Para tag="L3">
<Content_GB>string_6</Content_GB>
<Content_DE>German_translation of_string_6</Content_DE>
</Para>
<Para tag="Subbull">
<Content_GB>string_7</Content_GB>
<Content_DE>German_translation of_string_7</Content_DE>
</Para>
</Dictionary>
</Book>

Answer 2

This stylesheet makes use of <xsl:for-each-group>
First, groups the elements by their sequence of Para/#* values
Then, for each of those sequences, groups the Para using the number of following sibling elements that have attributes that start with "tag".
I have predicate filters on the matches for #*, to ensure that it is comparing the ones that start with "tag_". That may not be necessary, but would help ensure that it still worked if other attributes were added to the instance XML.
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="xml" version="1.0" xmlns="http://www.w3.org/1999/xhtml" encoding="UTF-8"
indent="yes"/>
<xsl:output omit-xml-declaration="yes" indent="yes"/>
<xsl:template match="#* | node()">
<xsl:copy>
<xsl:apply-templates select="#* | node()"/>
</xsl:copy>
</xsl:template>
<xsl:template match="text()" priority="1">
<xsl:value-of select="normalize-space(.)"/>
</xsl:template>
<xsl:template match="Section">
<xsl:for-each-group select="*"
group-adjacent="string-join(
Para/#*[starts-with(local-name(),'tag_')],'|')">
<Dictionary>
<xsl:for-each-group select="current-group()/Para"
group-by="count(
following-sibling::*[#*[starts-with(local-name(),'tag_')]])">
<Para tag="{(current-group()/#*[starts-with(local-name(),'tag_')])[1]}">
<xsl:copy-of select="current-group()/*"/>
</Para>
</xsl:for-each-group>
</Dictionary>
</xsl:for-each-group>
</xsl:template>
</xsl:stylesheet>
When applied to the sample input XML, produces the following output:
<Book>
<Dictionary>
<Para tag="L1">
<Content_GB>string_1</Content_GB>
<Content_DE>German_translation of_string_1</Content_DE>
</Para>
<Para tag="Illanc">
<Content_GB>string_2</Content_GB>
<Content_DE>German_translation of_string_2</Content_DE>
</Para>
<Para tag="|PLB">
<Content_GB>string_3</Content_GB>
<Content_DE>German_translation of_string_3</Content_DE>
</Para>
<Para tag="L1">
<Content_GB>string_4</Content_GB>
<Content_DE>German_translation of_string_4</Content_DE>
</Para>
<Para tag="Sub">
<Content_GB>string_5</Content_GB>
<Content_DE>German_translation of_string_5</Content_DE>
</Para>
<Para tag="L3">
<Content_GB>string_6</Content_GB>
<Content_DE>German_translation of_string_6</Content_DE>
</Para>
<Para tag="Subbull">
<Content_GB>string_7</Content_GB>
<Content_DE>German_translation of_string_7</Content_DE>
</Para>
</Dictionary>
<Dictionary>
<Para tag="L1">
<Content_DK>Partial_Danish_translation_of_string_1</Content_DK>
</Para>
<Para tag="L1_sub">
<Content_DK>Partial_Danish_translation_of_string_1</Content_DK>
</Para>
<Para tag="Illanc">
<Content_DK>Danish_translation_of_string_2</Content_DK>
</Para>
<Para tag="L1">
<Content_DK>Danish_translation_of_string_4</Content_DK>
</Para>
<Para tag="|PLB">
<Content_DK>Danish_translation_of_string_3</Content_DK>
</Para>
<Para tag="L3">
<Content_DK>Danish_translation_of_string_6</Content_DK>
</Para>
<Para tag="Sub">
<Content_DK>Danish_translation_of_string_5</Content_DK>
</Para>
<Para tag="Subbull">
<Content_DK>Danish_translation_of_string_7</Content_DK>
</Para>
</Dictionary>
</Book>