Re: [xsl] construct query string

[Greg Faron <gfaron@xxxxxxxxxxxxxxxxxx>]

At 01:36 PM 5/7/2002, you wrote:
> I'm attempting to construct a query string ("?param1=blah&param2=blah2",
> for example) using the values of a series of tags in an XML document. My
> first intuition was to create an XSL variable, and then send the
> transformer into a loop which concats each param tag onto that variable.
> However, after reading the W3C doc, it doesn't seem like that's feasible
> because you can't "shadow" a XSLT variable in the same template context,
> and you can't reference the variable you're trying to declare in the
> variable definition.  TIA.

  It rather depends on you XML and whether or not you're aware of the 
structure.  Let's say, for example, that you assume that the element in 
question is known to not have grandchildren, and that the text within the 
children do not have whitespace.  In other diagrams, it looks like this:
<foo>
  <a>text</a>
  <b/>
  <c></c>
  <d>more_text</d>
</foo>

  You can create "?a=text&b=&c=&d=more_text" using the stylesheet
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform";>
  <xsl:template match="/">
    <xsl:text>query-string = "</xsl:text>
    <xsl:apply-templates select="foo/*" mode="query"/>
    <xsl:text>"</xsl:text>
  </xsl:template>

  <xsl:template match="*" mode="query">
    <xsl:if test="position() = 1">
      <xsl:text>?</xsl:text>
    </xsl:if>
    <xsl:value-of select="local-name(.)"/>
    <xsl:text>=</xsl:text>
    <xsl:value-of select="string(.)"/>
    <xsl:if test="last() != position()">
      <xsl:text disable-output-escaping="yes"><![CDATA[&]]></xsl:text>
    </xsl:if>
  </xsl:template>
</xsl:stylesheet>


  If the text has whitespace, you'll need to convert it to an equivalent 
HTML-encoded character (i.e. a space becomes %20).  the same goes for other 
special characters like ampersands, punctuation, etc.


Greg Faron
Integre Technical Publishing Co.



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