Question

I would like to implement a split function/template in XSLT which takes as input a string and a delimiter and returns a split array of the string..

Or rather I’d like the ability to do something along the lines of:

<xsl:call-template name="F">
    <xsl:with-param name="input" select="'a,b,c,d,e'"/>
    <xsl:with-param name="replacement">
    <option value='$x'>$x</option>
</xsl:with-param>
</xsl:call-template>

which will give me

<option value='a'>a</option><option value='b'>b</option><option value='c'>c</option><option value='d'>d</option><option value='e'>e</option>

Question targeted at XSLT 1.0 (but i don’t mind learning how XSLT 2.0 does it too)

Answer 1

I. XSLT 2.0 solution

<xsl:stylesheet version="2.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>

 <xsl:template match="/">
  <xsl:variable name="vStr" select="'a,b,c,d,e'"/>

  <xsl:for-each select="tokenize($vStr, ',')">
   <option value="{.}"><xsl:value-of select="."/></option>
  </xsl:for-each>
 </xsl:template>
</xsl:stylesheet>

when this transformation is applied on ant XML document (not used), the wanted, correct result is produced:

<option value="a">a</option>
<option value="b">b</option>
<option value="c">c</option>
<option value="d">d</option>
<option value="e">e</option>

Explanation: Use of the standard XPath 2.0 function tokenize().

II. XSLT 1.0: Using the FXSL 1.x str-split-to-words function/template

This XSLT 1.0 transformation:

<xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
 xmlns:ext="http://exslt.org/common"
 exclude-result-prefixes="ext">
  <xsl:import href="strSplit-to-Words.xsl"/>
  <xsl:output indent="yes" omit-xml-declaration="yes"/>

    <xsl:template match="/">
      <xsl:variable name="vwordNodes">
        <xsl:call-template name="str-split-to-words">
          <xsl:with-param name="pStr" select="/"/>
          <xsl:with-param name="pDelimiters"
                          select="', '"/>
        </xsl:call-template>
      </xsl:variable>

      <xsl:apply-templates select=
       "ext:node-set($vwordNodes)/*"/>
    </xsl:template>

    <xsl:template match="word">
     <option value="{.}"><xsl:value-of select="."/></option>
    </xsl:template>
</xsl:stylesheet>

when applied on this XML document:

<t>a,b,c d,e</t>

produces the wanted, correct result:

<option value="a">a</option>
<option value="b">b</option>
<option value="c">c</option>
<option value="d">d</option>
<option value="e">e</option>

Do note The pDelimiters parameter (as its name says) can hold more than one delimiting character — in this case we use both ',' and ' '.

III. XSLT 1.0 solution using hand-written recursive named template:

This transformation:

<xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>

 <xsl:template match="text()" name="tokenize">
  <xsl:param name="pText" select="."/>
  <xsl:param name="pDelim" select="','"/>

  <xsl:if test="string-length($pText) > 0">
    <xsl:variable name="vToken" select=
    "substring-before(concat($pText,','), ',')"/>

    <option value="{$vToken}">
      <xsl:value-of select="$vToken"/>
    </option>

    <xsl:call-template name="tokenize">
     <xsl:with-param name="pText" select=
      "substring-after($pText,',')"/>
    </xsl:call-template>
  </xsl:if>
 </xsl:template>
</xsl:stylesheet>

when applied on this XML document:

<t>a,b,c,d,e</t>

produces the wanted, correct result:

<option value="a">a</option>
<option value="b">b</option>
<option value="c">c</option>
<option value="d">d</option>
<option value="e">e</option>

IV. Passing to the tokenize template in III above as a parameter a template/function to process each token

<xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
 xmlns:f="http://fxsl.sf.net" exclude-result-prefixes="f">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>

 <f:processToken/>

 <xsl:variable name="vFunc" select=
  "document('')/*/f:processToken[1]"/>

 <xsl:template match="text()" name="tokenize">
  <xsl:param name="pText" select="."/>
  <xsl:param name="pDelim" select="','"/>
  <xsl:param name="pProcessFunc" select="$vFunc"/>

  <xsl:if test="string-length($pText) > 0">
    <xsl:variable name="vToken" select=
    "substring-before(concat($pText,','), ',')"/>

    <xsl:apply-templates select="$pProcessFunc">
     <xsl:with-param name="arg1" select="$vToken"/>
    </xsl:apply-templates>

    <xsl:call-template name="tokenize">
     <xsl:with-param name="pText" select=
      "substring-after($pText,',')"/>
    </xsl:call-template>
  </xsl:if>
 </xsl:template>

 <xsl:template match="f:processToken">
  <xsl:param name="arg1"/>
    <option value="{$arg1}">
      <xsl:value-of select="$arg1"/>
    </option>
 </xsl:template>
</xsl:stylesheet>

when this transformation is applied to the same XML document as in III, the same, wanted, correct result is produced:

<option value="a">a</option>
<option value="b">b</option>
<option value="c">c</option>
<option value="d">d</option>
<option value="e">e</option>

Now, if we substitute the last template with this one:

 <xsl:template match="f:processToken">
  <xsl:param name="arg1"/>
    <p>
      <xsl:value-of select="$arg1"/>
    </p>
 </xsl:template>

again the desired result is produced:

<p>a</p>
<p>b</p>
<p>c</p>
<p>d</p>
<p>e</p>