remove elements based on external file - xslt

Question

I have an external setting file which has some nodes holiding attribute values of main xml document. I need to remove certian nodes from mian xml file if the attribute value is there in the setting file.
My setting file looks like this:
setting.xml
<xml>
<removenode titlename="abc" subtitlename="xyz"></removenode>
<removenode titlename="dvd" subtitlename="dvd"></removenode>
</xml>
Main.xml
<xml>
<title titlename="abc">
<subtitle subtitlename="xyz"></subtitle>
</title>
<title titlename="book">
<subtitle subtitlename="book sub title"></subtitle>
</title>
</xml>
Need a script which look for setting.xml file and remove the title element if titlename and subtitlename found in main.xml. The output should be
output.xml
<xml>
<title titlename="book">
<subtitle subtitlename="book sub title"></subtitle>
</title>
</xml>
I tried using document to read setting.xml file but not able to find how to do the match on main.xml file
<xsl:variable name="SuppressionSettings" select="document('Setting.xml')" />
<xsl:variable name="SuppressSetting" select="$SuppressionSettings/xml/removenode" />
.
Any hint how to implement it?

Answer 1

The key is to use an identity/copy pattern and, before each output, check the current (context) node isn't prohibited by the suppression rules nodeset.
<!-- get suppression settings -->
<xsl:variable name='suppression_settings' select="document('http://www.mitya.co.uk/xmlp/settings.xml')/xml/removenode" />
<!-- begin identity/copy -->
<xsl:template match="node()|#*">
<xsl:if test='not($suppression_settings[#titlename = current()/#titlename and #subtitlename = current()/subtitle/#subtitlename])'>
<xsl:copy>
<xsl:apply-templates select='node()|#*' />
</xsl:copy>
</xsl:if>
</xsl:template>
You can run it here (see output source - the 'abc' title node is omitted):
http://www.xmlplayground.com/9oCYKp

Answer 2

This XSLT indicated below works for the given document.
Note that I'm storing the contents of Setting.xml in a variable as you did, however, I'd then use that variable directly in my queries.
An important issue here is that in the match element of a template, variables cannot be used. Therefore, my template matches any <title> elements and then determines in an <xsl:choose> element whether the attributes match any values given in the settings file - if so, the <title> element will be omitted in the output.
As an explanation for why that test attribute in the <xsl:when> does what it should, imagine a comparison of someAttribute = someOtherAttribute not as a restriction that the attribute someAttribute must have the same value as the attribute someOtherAttribute, but rather as the condition that there must be any two attributes someAttribute and someOtherAttribute with the same value.
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output omit-xml-declaration="yes" indent="yes"/>
<xsl:variable name="SuppressionSettings" select="document('Setting.xml')" />
<xsl:template match="node()|#*">
<xsl:copy>
<xsl:apply-templates select="node()|#*"/>
</xsl:copy>
</xsl:template>
<xsl:template match="//title">
<xsl:choose>
<xsl:when test="(#titlename = $SuppressionSettings/xml/removenode/#titlename) and (subtitle/#subtitlename = $SuppressionSettings/xml/removenode/#subtitlename)"/>
<xsl:otherwise>
<xsl:copy>
<xsl:apply-templates select="node()|#*"/>
</xsl:copy>
</xsl:otherwise>
</xsl:choose>
</xsl:template>
</xsl:stylesheet>

Answer 3

Here's a more generic answer where the names of the attributes are not hard coded into the XSLT. Like O. R. Mapper pointed out, in XSLT 1.0 you can't use variable references in the match, so I put the document() directly in the predicate. This may not be as efficient as using a variable and then testing the variable.
XSLT 1.0
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output indent="yes"/>
<xsl:strip-space elements="*"/>
<xsl:template match="node()|#*">
<xsl:copy>
<xsl:apply-templates select="node()|#*"/>
</xsl:copy>
</xsl:template>
<xsl:template match="*[#* = document('setting.xml')/*/removenode/#*]"/>
</xsl:stylesheet>
XML Output (using your 2 xml files with main.xml as the input)
<xml>
<title titlename="book">
<subtitle subtitlename="book sub title"/>
</title>
</xml>