I want to group a XML by a trigger or flag value. I can only use XSLT 1.0. Original XML:
<?xml version = "1.0" encoding = "utf-8"?>
<root>
<image>
<field level = "system" name = "Image Filename" value = "Batch121_2_1.tif"/>
<field level = "document" name = "groupId" value = "1"/>
<field level = "document" name = "scanDokumentPos" value = "1 "/>
</image>
<image>
<field level = "system" name = "Image Filename" value = "Batch121_2_2.tif"/>
<field level = "document" name = "groupId" value = "0"/>
<field level = "document" name = "scanDokumentPos" value = "1 "/>
</image>
<image>
<field level = "system" name = "Image Filename" value = "Batch121_2_3.tif"/>
<field level = "document" name = "groupId" value = "0"/>
<field level = "document" name = "scanDokumentPos" value = "1 "/>
</image>
<image>
<field level = "system" name = "Image Filename" value = "Batch121_3_1.tif"/>
<field level = "document" name = "groupId" value = "0"/>
<field level = "document" name = "scanDokumentPos" value = "2 "/>
</image>
<image>
<field level = "system" name = "Image Filename" value = "Batch121_3_2.tif"/>
<field level = "document" name = "groupId" value = "0"/>
<field level = "document" name = "scanDokumentPos" value = "2 "/>
</image>
<image>
<field level = "system" name = "Image Filename" value = "Batch121_7_1.tif"/>
<field level = "document" name = "groupId" value = "1"/>
<field level = "document" name = "scanDokumentPos" value = "6 "/>
</image>
<image>
<field level = "system" name = "Image Filename" value = "Batch121_7_2.tif"/>
<field level = "document" name = "groupId" value = "0"/>
<field level = "document" name = "scanDokumentPos" value = "6 "/>
</image>
<image>
<field level = "system" name = "Image Filename" value = "Batch121_8_1.tif"/>
<field level = "document" name = "groupId" value = "0"/>
<field level = "document" name = "scanDokumentPos" value = "7 "/>
</image>
<image>
<field level = "system" name = "Image Filename" value = "Batch121_8_2.tif"/>
<field level = "document" name = "groupId" value = "0"/>
<field level = "document" name = "scanDokumentPos" value = "7 "/>
</image>
<image>
<field level = "system" name = "Image Filename" value = "Batch121_9_1.tif"/>
<field level = "document" name = "groupId" value = "1"/>
<field level = "document" name = "scanDokumentPos" value = "8 "/>
</image>
<image>
<field level = "system" name = "Image Filename" value = "Batch121_10_1.tif"/>
<field level = "document" name = "groupId" value = "1"/>
<field level = "document" name = "scanDokumentPos" value = "9 "/>
</image>
</root>
Result should be:
<document>
<childdocuments>
<document GroupID=""> <!-- grouped because of groupId=1 -->
<childdocuments>
<document GroupID="1"> <!-- scanDokumentPos --> <!-- grouped because of groupId=0 and scanDokumentPos=1 -->
<pages>
<page path="Batch121_2_1.tif"> <!-- Image Filename -->
<page path="Batch121_2_2.tif"> <!-- Image Filename -->
<page path="Batch121_2_3.tif"> <!-- Image Filename -->
</page>
</document>
<document GroupID="2"> <!-- scanDokumentPos --> <!-- grouped because of groupId=0 and scanDokumentPos=2 -->
<pages>
<page path="Batch121_3_1.tif"> <!-- Image Filename -->
<page path="Batch121_3_2.tif"> <!-- Image Filename -->
</page>
</document>
</childdocuments>
</document>
<document GroupID=""> <!-- start new document because of groupId=1 -->
<childdocuments>
<document GroupID="6"> <!-- scanDokumentPos --> <!-- grouped because of groupId=0 and scanDokumentPos=6 -->
<pages>
<page path="Batch121_7_1.tif"> <!-- Image Filename -->
<page path="Batch121_7_2.tif"> <!-- Image Filename -->
</page>
</document>
<document GroupID="7"> <!-- scanDokumentPos --> <!-- grouped because of groupId=0 and scanDokumentPos=7 -->
<pages>
<page path="Batch121_8_1.tif"> <!-- Image Filename -->
<page path="Batch121_8_2.tif"> <!-- Image Filename -->
</page>
</document>
</childdocuments>
</document>
<document GroupID=""> <!-- start new document because of groupId=1 -->
<childdocuments>
<document GroupID="8"> <!-- scanDokumentPos --> <!-- grouped because of groupId=0 and scanDokumentPos=8 -->
<pages>
<page path="Batch121_9_1.tif"> <!-- Image Filename -->
</page>
</document>
</childdocuments>
</document>
<document GroupID=""> <!-- start new document because of groupId=1 -->
<childdocuments>
<document GroupID="9"> <!-- scanDokumentPos --> <!-- grouped because of groupId=0 and scanDokumentPos=9 -->
<pages>
<page path="Batch121_10_1.tif"> <!-- Image Filename -->
</page>
</document>
</childdocuments>
</document>
</childdocuments>
</document>
The first grouping-key is groupId. If 1 start new document on level 1. So all elements after groupId=1 until next groupId=1 or the end of file belongs to one group. The second grouping-key is scanDokumentPos. Group all the pages to one document which has the same scanDokumentPos.
Testing: http://xsltransform.net/3N7GxDx/3
Like mentioned in the comments, grouping in XSLT 1.0 is best done using Muenchian Grouping.
The example given (https://stackoverflow.com/a/58525214/3016153) is a good one, but the difference with your question is your first grouping is more like a "group-starting-with" than just grouping on a value.
What I would do is create 2 keys.
The first selects image elements that don't have a groupId of "1" based on the generated id of the first preceding sibling that has a groupId of "1".
The second selects image elements that don't have a groupId of "1" based on a combination of the generated id (see above) and the "scanDokumentPos" value.
Here's an example. I didn't handle the processing of the image elements. I only show the grouping. The handling of the image elements should be trivial.
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output indent="yes"/>
<xsl:strip-space elements="*"/>
<xsl:key name="doc_group" match="image[not(field[@name='groupId']/@value='1')]"
use="generate-id(preceding-sibling::image[field[@name='groupId']/@value='1'][1])"/>
<xsl:key name="doc_pos_group" match="image[not(field[@name='groupId']/@value='1')]"
use="concat(generate-id(preceding-sibling::image[field[@name='groupId']/@value='1'][1]),'|',
field[@name='scanDokumentPos']/@value)"/>
<xsl:template match="@*|node()">
<xsl:copy>
<xsl:apply-templates select="@*|node()"/>
</xsl:copy>
</xsl:template>
<xsl:template match="/*">
<document>
<childdocuments>
<xsl:for-each select="image[field[@name='groupId']/@value='1']">
<xsl:variable name="curr_image" select="."/>
<xsl:variable name="curr_id" select="generate-id()"/>
<document GroupID="">
<childdocuments>
<xsl:if test="1 >= count(key('doc_group',$curr_id))">
<document GroupID="{normalize-space(field[@name='scanDokumentPos']/@value)}">
<pages>
<xsl:apply-templates select="$curr_image"/>
</pages>
</document>
</xsl:if>
<xsl:for-each select="key('doc_group',$curr_id)[count(.|key('doc_pos_group',
concat($curr_id,'|',field[@name='scanDokumentPos']/@value))[1])=1]">
<xsl:variable name="doc_pos" select="field[@name='scanDokumentPos']/@value"/>
<document GroupID="{normalize-space($doc_pos)}">
<pages>
<xsl:apply-templates
select="$curr_image[field[@name='scanDokumentPos']/@value=$doc_pos]|
key('doc_pos_group',concat($curr_id,'|',$doc_pos))"/>
</pages>
</document>
</xsl:for-each>
</childdocuments>
</document>
</xsl:for-each>
</childdocuments>
</document>
</xsl:template>
</xsl:stylesheet>