Doh!  Got it.  Needed to add:

xmlns:umbraco.contour="urn:umbraco.contour"

...to the xsl:stylesheet tag, and declare 'umbraco.contour' in the exclude-result-prefixes attribute of the XSLT file.

Actually, although that's supressed the error on save, the macro still errors, and it seems to be related to the use of the 'umbraco.contour' extension.  The code I have is this:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE xsl:stylesheet [ <!ENTITY nbsp "&#x00A0;"> ]>
<xsl:stylesheet
  version="1.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:msxml="urn:schemas-microsoft-com:xslt"
  xmlns:umbraco.library="urn:umbraco.library" xmlns:Exslt.ExsltCommon="urn:Exslt.ExsltCommon" xmlns:Exslt.ExsltDatesAndTimes="urn:Exslt.ExsltDatesAndTimes" xmlns:Exslt.ExsltMath="urn:Exslt.ExsltMath" xmlns:Exslt.ExsltRegularExpressions="urn:Exslt.ExsltRegularExpressions" xmlns:Exslt.ExsltStrings="urn:Exslt.ExsltStrings" xmlns:Exslt.ExsltSets="urn:Exslt.ExsltSets" xmlns:CWS.Twitter="urn:CWS.Twitter" xmlns:contourpoll="urn:contourpoll" xmlns:umbraco.contour="urn:umbraco.contour" xmlns:PS.XSLTsearch="urn:PS.XSLTsearch"
  exclude-result-prefixes="msxml umbraco.library Exslt.ExsltCommon Exslt.ExsltDatesAndTimes Exslt.ExsltMath Exslt.ExsltRegularExpressions Exslt.ExsltStrings Exslt.ExsltSets CWS.Twitter contourpoll PS.XSLTsearch umbraco.contour ">

<xsl:output method="xml" omit-xml-declaration="yes"/>
<xsl:param name="currentPage"/>
<xsl:param name="formid" select="/macro/formid" />
<xsl:template match="/">
  <xsl:value-of select="$formid"/>
  <xsl:if test="$formid">
    
<!--
    <xsl:variable name="records" select="umbraco.contour:GetRecordsFromForm($formid)"/>
    <xsl:variable name="numberOfRecords" select="count($records/uformrecord)" />
    <div class="results" style="width:300px">
      <h3>Poll results</h3>
      <xsl:for-each select="contourpoll:PossibleAnswers($formid)//question">
        <xsl:variable name="numberOfAnswers" select="count(./answer)" />
        <h4><xsl:value-of select="caption"/></h4>
        <ul style="list-style:none;padding-left:0px;margin-left:0px;">
          <xsl:for-each select=".//answer">
            <xsl:sort select="count($records//value [@key = current()/@id])" data-type="number" order="descending"/>
            <xsl:variable name="currentId" select="@id" />
            <xsl:variable name="currentVotes" select="count($records//value [@key = $currentId])" />
            <xsl:variable name="currentPercentage" select="round (($currentVotes div $numberOfRecords) * 100)"/>
            <li>
              <xsl:value-of select="."/>
              <div class="scorebarcontainer" style="width:100%;background-color:#eee;height:20px">
                <div class="scorebar" style="width:{$currentPercentage}%;background-color:#ccc;height:20px"></div>
              </div>
            </li>
          </xsl:for-each>
        </ul>
      </xsl:for-each>
    </div>
  -->
  </xsl:if>
</xsl:template>

</xsl:stylesheet>

The '$formid' variable outputs fine, but when I output umbraco.contour:GetRecordsFromForm($formid) it errors when I run the macro in a page.

I notice that when I click the 'insert value-of' button in the XSLT editor then click 'get extension' there is no 'umbraco.contour' option in the first extension selector.

I think basically I need to register the umbraco.contour extension in the config file, but (a) I'm not sure why this wouldn't be done as part of the contour installation process; (b) I thought xslt extensions actually registered automatically in 4.7 and (c) if I'm registering manually via the config file, I'm not sure what the full <ext> attribute values should be.

Anyone?

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