Re: parsing strings

On Mon, 7 May 2001, William Lam wrote:

> Hi,
> 
> I'm still relatively new to XSL.
> 
> I am looking for a string tokenizer, similar to the
> one available in the java library.

Well, you can do this with XSL, no need for a tokenizer, see below...

> I have a source node with delimited key/value pairs
> 
> <text>A:a;B:b;C:c;D:d</text>
> 
> I need to extract the key value pairs to look similar
> to
> 
> <items>
> <key>A</key>
> <value>a</value>
> <key>B</key>
> <value>b</value>
> <key>C</key>
> <value>c</value>
> <key>D</key>
> <value>d</value>
> </items>

Try the following stylesheet:

--------------------------8< snip >8-------------------------
<?xml version="1.0" encoding="iso-8859-1"?>

<xsl:stylesheet xmlns:xsl='http://www.w3.org/1999/XSL/Transform' version="1.0">

<xsl:output method="xml" indent="yes"/>

<xsl:template match="text">
  <items>
    <xsl:call-template name="process-tokens">
      <xsl:with-param name="tokenstring" select="."/>
      <xsl:with-param name="separator" select="';'"/>
    </xsl:call-template>
  </items>
</xsl:template>


<xsl:template name="process-tokens">
  <xsl:param name="tokenstring"/>
  <xsl:param name="separator"/>

  <xsl:variable name="pre">
    <xsl:choose>
      <xsl:when test="contains($tokenstring, $separator)">
        <xsl:value-of select="substring-before($tokenstring,$separator)"/>
      </xsl:when>
      <xsl:otherwise>
        <xsl:value-of select="$tokenstring"/>
      </xsl:otherwise>
    </xsl:choose>
  </xsl:variable>
  <xsl:variable name="post" select="substring-after($tokenstring,$separator)"/>

  <xsl:message>pre: <xsl:value-of select="$pre"/></xsl:message>
  <xsl:message>post: <xsl:value-of select="$post"/></xsl:message>
  <xsl:call-template name="process-single-token">
    <xsl:with-param name="token" select="$pre"/>
  </xsl:call-template>
  <xsl:if test="$post">
    <xsl:call-template name="process-tokens">
      <xsl:with-param name="tokenstring" select="$post"/>
      <xsl:with-param name="separator" select="$separator"/>
    </xsl:call-template>
  </xsl:if>
</xsl:template>

<xsl:template name="process-single-token">
  <xsl:param name="token"/>

  <xsl:if test="$token">
    <xsl:variable name="key" select="substring-before($token,':')"/>
    <xsl:variable name="value" select="substring-after($token,':')"/>

    <key>
      <xsl:value-of select="$key"/>
    </key>
    <value>
      <xsl:value-of select="$value"/>
    </value>
  </xsl:if>

</xsl:template>

</xsl:stylesheet>

--------------------------8< snip >8-------------------------

Hope this helps.

--Swen



 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list