Substring the result of for loop in XSL

Question

Seeking one help on xsl payment file template. I have to restrict the length of a tag after for loop to 140 characters. In attached xml, after concatenating the DocumentPayable/DocumentNumber/ReferenceNumber, I want to print only 140 characters in Ustrd tag for one payment info tag (i.e. PmtInf). How can this be achieved via xsl? I am attaching the current working xsl template wherein I am able to concatenate the values and xml file which has got the sample data.

<xsl:variable name="varustrd" select="oraext:create-delimited-string (DocumentPayable/DocumentNumber/ReferenceNumber, ',' )"/>

<xsl:for-each select="DocumentPayable">

<Ustrd>
<xsl:value-of select="(DocumentNumber/ReferenceNumber)"/>
</Ustrd>

<Ustrd1>
<xsl:value-of select="$varustrd"/>
</Ustrd1>

Answer 1

You can fill a variable with the concatenation and the output only its first 140 characters:

<xsl:variable name="char140">
  <xsl:for-each select="DocumentPayable/DocumentNumber/ReferenceNumber">
    <xsl:value-of select="."/>
    <xsl:if test="position() != last()">,</xsl:if>
  </xsl:for-each>
</xsl:variable>
<Ustrd>
  <xsl:value-of select="substring($char140,1,140)"/>
</Ustrd>

If you want to produce multiple <Ustrd> elements, each with 140 characters, you need a recursive template

<xsl:call-template name="char140">
  <xsl:with-param name="s" select="$char140"/
</xsl:call-template>

which is defined in a top-level element

<xsl:template name="char140">
  <xsl:param name="s"/>
  <xsl:if test="$s">
    <Ustrd>
      <xsl:value-of select="substring($s,1,140)"/>
    </Ustrd>
    <xsl:call-template name="char140">
      <xsl:with-param name="s" select="substring($s,141)"/>
    </xsl:call-template>
  </xsl:if>
</xsl:template>