XSLT: How can I identify the list of values are same? - iteration

Question

I got the following xml snippet.
<Root>
<SomeTags></SomeTags>
<Values>
<dateFrom>date 1<dateFrom>
<dateEnd>date 2<dateEnd>
<value1>10</value1>
<value2>5</value2>
</Values>
More Values here....
.....................
.....................
<Values>
<dateFrom>date n<dateFrom>
<dateEnd>date n+1<dateEnd>
<value1>10</value1>
<value2>5</value2>
</Values>
</Root>
I want to compare all <value1> values and <value2> values. If they are same, I want to compress the whole as following:
If values1 == same in all Values and If values2== same in all Values then this should the output.
<Values>
<dateFrom>date 1<dateFrom> should be from the first Values item
<dateEnd>date n+1<dateEnd> should be from the last Values item
<value1>10</value1>
<value2>5</value2>
</Values>
Else
different template.
How can i achieve this in XSLT (1.0) in BizTalk 2009 ?
I know iteration. for-each. But is there a way to break as in procedural language. Can I somehow compare each value and return a boolean saying all values are same or not.. ??
Thank you all for your responses.

Answer 1

This transformation:
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output omit-xml-declaration="yes" indent="yes"/>
<xsl:strip-space elements="*"/>
<xsl:template match="node()|#*">
<xsl:copy>
<xsl:apply-templates select="node()|#*"/>
</xsl:copy>
</xsl:template>
<xsl:template match="Values">
<xsl:if test=
"not(preceding-sibling::Values
[value1=current()/value1 and value2=current()/value2])">
<Values>
<xsl:apply-templates select="value1|value2"/>
</Values>
</xsl:if>
</xsl:template>
</xsl:stylesheet>
when applied on the following well-formed XML document (produced from the severely malformed text that is provided in the question):
<t>
<Values>
<dateFrom>date 1</dateFrom>
<dateEnd>date 2</dateEnd>
<value1>10</value1>
<value2>5</value2>
</Values>
<somethingElse/>
<Values>
<dateFrom>date n</dateFrom>
<dateEnd>date n+1</dateEnd>
<value1>10</value1>
<value2>5</value2>
</Values>
</t>
produces the wanted result:
<t>
<Values>
<value1>10</value1>
<value2>5</value2>
</Values>
<somethingElse/>
</t>
Explanation:
Just applying the most fundamental design pattern of XSLT: Using and overriding the identity rule.