[xsl] Variables in XSLT

["Paul Delange" <Paul.Delange@xxxxxxx>]

Hi All,

Sorry for a newbie question, I'm an very experienced programming taking my
first crack at an XSLT program.

Essentially I need to extract the www.this_is_the_desired_url.com data from
the XML below.


        <VNDR_LOC_SCROL class="R">
          <VENDOR_LOC class="R">
            <VNDR_LOC IsChanged="Y">1</VNDR_LOC>
            <VNDR_URL class="R">
              <EFFDT IsChanged="Y">2006-01-26</EFFDT>
              <LINE_NBR IsChanged="Y">1</LINE_NBR>
              <URL IsChanged="Y">www.this_is_the_desired_url.com</URL>
            </VNDR_URL>
            <VNDR_URL class="R">
              <EFFDT IsChanged="Y">2006-01-26</EFFDT>
              <LINE_NBR IsChanged="Y">2</LINE_NBR>
              <URL IsChanged="Y">www.this_is_an_unwanted_url.com</URL>
            </VNDR_URL>
          </VENDOR_LOC>
          <VENDOR_LOC class="R">
            <VNDR_LOC IsChanged="Y">1</VNDR_LOC>
            <VNDR_URL class="R">
              <EFFDT IsChanged="Y">1901-01-01</EFFDT>
              <LINE_NBR IsChanged="Y">1</LINE_NBR>
              <URL IsChanged="Y">www.this_is_another_unwanted_url.com</URL>
            </VNDR_URL>
          </VENDOR_LOC>
        </VNDR_LOC_SCROL>

The deciding factors in selecting that <URL> tag over the other's are;
- It has maximum effective date (<EFFDT> = 2006-01-26)
- It's effective date does not exceed the current date.
- It is the first url (<LINE_NBR> = 1) on that date. (This should be a
simple <xsl:if test="LINE_NBR" = '1'">)

With my conventional programming background, I want to define a $maxeffdt
variable BEFORE I call the template below and this do some kind of <xsl:if
test="EFFDT = $maxeffdt> but I'm not sure this is doable/appropriate in the
new XSLT world.

My current code looks like this;

<xsl:template match="VENDOR_LOC">
   <xsl:if test="VNDR_LOC = ../../DEFAULT_LOC">          <--Eliminates
non-default locations not shown above
      <C3><xsl:value-of select="VNDR_LOC" /></C3>
      <HOMEPAGE><xsl:value-of select="VNDR_URL/URL" /></HOMEPAGE>
   </xsl:if>
</xsl:template>

Can someone point me in the right direction with appropriateness/syntax?
FYI, I am using a PeopleSoft Application Engine program to transform my
data.