XSLT field validation - xslt

Question

I have a requirement to validate a field content which is within a 1..N structure, so the data come in pairs of RESULT_ID and RESULT_VALUE.
If "<" is found in Result.Min_Limit characteristic, its value must be put in the Max_Limit characteristic target field and Min_Limit must be cleared out in target structure.
Sample of source structure with data:
<?xml version="1.0" encoding="UTF-8"?>
<TEST>
<RESULTS>
<RESULT>
<D_RESULT>
<D_RESULT_ID>Result.Derived</D_RESULT_ID>
<D_RESULT_VALUE>59W</D_RESULT_VALUE>
</D_RESULT>
<D_RESULT>
<D_RESULT_ID>Result.Min_Limit</D_RESULT_ID>
<D_RESULT_VALUE><=600.0000</D_RESULT_VALUE>
</D_RESULT>
<D_RESULT>
<D_RESULT_ID>Result.Max_Limit</D_RESULT_ID>
<D_RESULT_VALUE/>
</D_RESULT>
<D_RESULT>
<D_RESULT_ID>Result.FailedCriticalLvl</D_RESULT_ID>
<D_RESULT_VALUE>false</D_RESULT_VALUE>
</D_RESULT>
</RESULT>
</RESULTS>
</TEST>
Expected target structure should be as follow:
<?xml version="1.0" encoding="UTF-8"?>
<TEST>
<RESULTS>
<RESULT>
<D_RESULT>
<D_RESULT_ID>Result.Derived</D_RESULT_ID>
<D_RESULT_VALUE>59W</D_RESULT_VALUE>
</D_RESULT>
<D_RESULT>
<D_RESULT_ID>Result.Min_Limit</D_RESULT_ID>
<D_RESULT_VALUE/>
</D_RESULT>
<D_RESULT>
<D_RESULT_ID>Result.Max_Limit</D_RESULT_ID>
<D_RESULT_VALUE><=600.0000</D_RESULT_VALUE>
</D_RESULT>
<D_RESULT>
<D_RESULT_ID>Result.FailedCriticalLvl</D_RESULT_ID>
<D_RESULT_VALUE>false</D_RESULT_VALUE>
</D_RESULT>
</RESULT>
</RESULTS>
</TEST>
I've created a variable to store Min_Limit value if it contains the "<" character, and it works fine when the pointer is still in Min_Limit characteristic.
When it flips to next characteristic (Max_Limit), the variable seems to loose its value and therefore I have no visibility of Min_Limit value anymore to assign the value to Max_Limit characteristic.
Currently, what I have is like the following:
......
<xsl:for-each select="a:D_RESULT">
<D_RESULT>
<D_RESULT_ID>
<xsl:value-of select="a:D_RESULT_ID"/>
</D_RESULT_ID>
<D_RESULT_VALUE>
<xsl:value-of select="a:D_RESULT_VALUE"/>
</D_RESULT_VALUE>
</D_RESULT>
</xsl:for-each>
</RESULT>
... other fields
I've found some interesting conversations here with some approaches I believe would help solving this, but I'm not sure I understood enough to apply to my scenario.
This is one of those XSLT: nested for-each and dynamic variable
Would anyone suggests something to solve this?
Many thanks in advance!
Rafael.

Answer 1

Here's one way you could look at it:
XSLT 1.0
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="xml" version="1.0" encoding="UTF-8" indent="yes"/>
<xsl:strip-space elements="*"/>
<!-- identity transform -->
<xsl:template match="#*|node()">
<xsl:copy>
<xsl:apply-templates select="#*|node()"/>
</xsl:copy>
</xsl:template>
<xsl:template match="D_RESULT_VALUE[../D_RESULT_ID='Result.Min_Limit' and contains(., '<')] ">
<xsl:copy/>
</xsl:template>
<xsl:template match="D_RESULT_VALUE[../D_RESULT_ID='Result.Max_Limit' and contains(../../D_RESULT[D_RESULT_ID='Result.Min_Limit']/D_RESULT_VALUE, '<')] ">
<xsl:copy>
<xsl:value-of select="../../D_RESULT[D_RESULT_ID='Result.Min_Limit']/D_RESULT_VALUE"/>
</xsl:copy>
</xsl:template>
</xsl:stylesheet>
Demo: http://xsltransform.net/3NzcBtA