XSLT split elements by splitter-element - xslt

Question

I've tried to combine solutions to the similar questions asked here but all of them work in very specific cases. My case is the following: I have an arbitrary xml document which contains some tags, let's say <separator/>. What I want is to split parent elements of these tags like that:
INPUT:
<some_tag some_attr="some_value">
some text
<some_other_tag>some another text</some_other_tag>
<separator/>
some other content
</some_tag>
OUTPUT:
<some_tag some_attr="some_value">
some text
<some_other_tag>some another text</some_other_tag>
</some_tag>
<separator/>
<some_tag some_attr="some_value">
some other content
</some_tag>
Also, I am limited to XSLT 1.0 since Xalan is used in the project

Answer 1

Either use sibling recursion or use a key to find the nodes "belonging" to a separator. Additional care is needed to copy stuff following the last separator:
<xsl:stylesheet
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
version="1.0">
<xsl:output method="xml" indent="yes"/>
<xsl:key name="sep" match="*[separator]/node()[not(self::separator)]" use="generate-id(following-sibling::separator[1])"/>
<xsl:template match="#* | node()">
<xsl:copy>
<xsl:apply-templates select="#* | node()"/>
</xsl:copy>
</xsl:template>
<xsl:template match="*[separator]">
<xsl:apply-templates select="separator" mode="split"/>
<xsl:if test="separator[last()]/following-sibling::node()">
<xsl:copy>
<xsl:apply-templates select="#* | separator[last()]/following-sibling::node()"/>
</xsl:copy>
</xsl:if>
</xsl:template>
<xsl:template match="separator" mode="split">
<xsl:apply-templates select=".." mode="split">
<xsl:with-param name="separator" select="."/>
</xsl:apply-templates>
<xsl:copy-of select="."/>
</xsl:template>
<xsl:template match="*" mode="split">
<xsl:param name="separator"/>
<xsl:copy>
<xsl:apply-templates select="#* | key('sep', generate-id($separator))"/>
</xsl:copy>
</xsl:template>
</xsl:stylesheet>
https://xsltfiddle.liberty-development.net/pPqsHTc
Note that if you use Xalan Java then in the Java world this is much easier with Saxon 9 and XSLT 2/3's <xsl:for-each-group select="node()" group-adjacent="boolean(self::separator)"> or group-starting-with="separator".