Apply a propertie file to a different xml file

Clyne · December 30th, 2006, 11:39 AM

Hi folks,
I want to write a XSLT gets properties e.g. XPath-Expression from one file and apply it to a different one. I tried this:

Code:

<rule>

  <xpath attribute1="p1" attribute2="p1_"/>
  <xpath attribute1="p2" attribute2="p2_"/>
</rule>

Code:

<test>
  <p1/>
  <p2/>
  <p3/>
</test>

Code:

<test>
  <p1_/>
  <p2_/>
  <p3/>
</test>

Code:

<xsl:param name="document" select="document('XMLfile.xml')"/>
<xsl:template match="/rule//xpath">
  <xsl:apply-templates select="$document" mode="document_">
    <xsl:with-param name="attribute1" select="./@attribute1" tunnel="yes"/>
    <xsl:with-param name="attribute2" select="./@attribute2" tunnel="yes"/>
  </xsl:apply-templates>
</xsl:template>

<xsl:template match="/" mode="document_">
  <xsl:param name="attribute1"/>
  xsl:apply-templates select="$attribute1" mode="tag_"/>
</xsl:template>

<xsl:template match="p1" mode="tag_">
  <xsl:param name="attribute2"/>
  <xsl:element name="{$attribute2}"/>
</xsl:template>

The code is not complete, but I failure to apply the p1-template. Could anybody help me?[u]</u>[u]</u>[u]</u>[u]</u>
Thanks a lot.
Clyne

mhkay · December 30th, 2006, 06:26 PM

There's no standard way in XSLT of constructing an XPath expression at run-time (or reading it from a file at run-time) and then evaluating it. Several products have extension functions to do this (e.g. saxon:evaluate() in Saxon). Alternatively, consider using XSLT to construct a stylesheet that incorporates the XPath expressions, and then executing that stylesheet.

Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference

Clyne · December 30th, 2006, 09:44 PM

Thanks Michael. I used the extension function but it doesn't work:

Code:

...
<xsl:apply-templates select="$document" mode="document_">
  <xsl:with-param name="attribute1" select="./@attribute1" tunnel="yes"/>
</xsl:apply-templates>
...
<xsl:template match="/" mode="document_">
  <xsl:param name="attribute1" select="default"/>
  <xsl:variable name="test" select="concat('/*//',$attribute1)"/>
  <xsl:value-of select="$attribute1"/>
  <xsl:apply-templates select="saxon:evaluate($test)" mode="tag_"/>
</xsl:template>

The value-of select gives the values of with-param back and overwrite default respectively. But in saxon:evaluate(..) I get an exception: Static error in XPath expression supplied to saxon:evaluate: XPath syntax error at char 4 in {/*//}: Unexpected token "<eof>" in path expression. Did I overlook a fault? Thanks at forward.

mhkay · December 31st, 2006, 11:17 AM

The argument supplied to saxon:evaluate() must be a valid XPath expression. "/*//" is not a valid XPath expression.

Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference

mhkay · December 31st, 2006, 11:19 AM

Looking more deeply, $attribute1 is taking its default value of "", because the supplied parameter said tunnel="yes" and the xsl:param declaration implies tunnel="no".

Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference

Clyne · January 2nd, 2007, 10:56 AM

Thanks Michael. The point with the 'tunnel'-Attribute I did not see.