Create a recursive string function for adding a sequence - xslt

Question

I've a challenging problem and so far I wasn't able to solve.
Within my xlst I have variable which contains a string.
I need to add the following sequence [eol] to this string.
On a fix position namely every 65 characters
I thought to use a function or template to recursive add this charackter.
The reason is that the string length can variate in length.
<xsl:function name="funct:insert-eol" as="xs:string" >
<xsl:param name="originalString" as="xs:string?"/>
<xsl:variable name="length">
<xsl:value-of select="string-length($originalString)"/>
</xsl:variable>
<xsl:variable name="start" as="xs:integer">
<xsl:value-of select="1"/>
</xsl:variable>
<xsl:variable name="eol" as="xs:integer">
<xsl:value-of select="65"/>
</xsl:variable>
<xsl:variable name="newLines">
<xsl:value-of select="$length idiv number('65')"/>
</xsl:variable>
<xsl:for-each select="1 to $newLines">
<xsl:value-of select="substring($originalString, $start, $eol)" />
</xsl:for-each>
</xsl:function>
The more I write code the more variables I need to introduce. This is still my lack on understanding.
For example we want every 5 chars an [eol]
aaaaaaabbbbbbccccccccc
aaaaa[eol]aabbb[eol]bbbcc[eol]ccccc[eol]cc
Hope someone has a starting point for me..
Regards Dirk

Answer 1

Rather straight-forward and short -- no recursion is necessary (and can even be specified as a single XPath expression):
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="text"/>
<xsl:param name="pLLength" select="5"/>
<xsl:template match="/*">
<xsl:variable name="vText" select="string()"/>
<xsl:for-each select="1 to string-length($vText) idiv $pLLength +1">
<xsl:value-of select="substring($vText, $pLLength*(position()-1)+1, $pLLength)"/>
<xsl:if test=
"not(position() eq last()
or position() eq last() and string-length($vText) mod $pLLength)">[eol]</xsl:if>
</xsl:for-each>
</xsl:template>
</xsl:stylesheet>
When this transformation is applied on this XML document:
<t>aaaaaaabbbbbbccccccccc</t>
the wanted, correct result is produced:
aaaaa[eol]aabbb[eol]bbbcc[eol]ccccc[eol]cc
When this XML document is processed:
<t>aaaaaaabbbbbbcccccccccddd</t>
again the wanted, correct result is produced:
aaaaa[eol]aabbb[eol]bbbcc[eol]ccccc[eol]ccddd[eol]

Answer 2

You can treat it as a grouping problem, using for-each-group:
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:mf="http://example.com/mf"
exclude-result-prefixes="xs mf">
<xsl:function name="mf:insert-eol" as="xs:string">
<xsl:param name="input" as="xs:string"/>
<xsl:param name="chunk-size" as="xs:integer"/>
<xsl:value-of>
<xsl:for-each-group select="string-to-codepoints($input)" group-by="(position() - 1) idiv $chunk-size">
<xsl:if test="position() gt 1"><xsl:sequence select="'eol'"/></xsl:if>
<xsl:sequence select="codepoints-to-string(current-group())"/>
</xsl:for-each-group>
</xsl:value-of>
</xsl:function>
<xsl:template match="#* | node()">
<xsl:copy>
<xsl:apply-templates select="#* , node()"/>
</xsl:copy>
</xsl:template>
<xsl:template match="text">
<xsl:copy>
<xsl:sequence select="mf:insert-eol(., 5)"/>
</xsl:copy>
</xsl:template>
</xsl:stylesheet>
That stylesheet transforms
<root>
<text>aaaaaaabbbbbbccccccccc</text>
</root>
into
<root>
<text>aaaaaeolaabbbeolbbbcceolccccceolcc</text>
</root>

Answer 3

Try this one:
<?xml version='1.0' ?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xsl:param name="TextToChange" select="'aaaaaaabbbbbbccccccccc'"/>
<xsl:param name="RequiredLength" select="xs:integer(5)"/>
<xsl:template match="/">
<xsl:call-template name="AddText"/>
</xsl:template>
<xsl:template name="AddText">
<xsl:param name="Text" select="$TextToChange"/>
<xsl:param name="TextLength" select="string-length($TextToChange)"/>
<xsl:param name="start" select="xs:integer(1)"/>
<xsl:param name="end" select="$RequiredLength"/>
<xsl:choose>
<xsl:when test="$TextLength gt $RequiredLength">
<xsl:value-of select="substring($Text,$start,$end)"/>
<xsl:text>[eol]</xsl:text>
<xsl:call-template name="AddText">
<xsl:with-param name="Text" select="substring-after($Text, substring($Text,$start,$end))"/>
<xsl:with-param name="TextLength"
select="string-length(substring-after($Text, substring($Text,$start,$end)))"/>
</xsl:call-template>
</xsl:when>
<xsl:otherwise>
<xsl:value-of select="$Text"/>
</xsl:otherwise>
</xsl:choose>
</xsl:template>
</xsl:stylesheet>