Generating multiple metadata elements in user.head.content

[Xmplar <info@xmplar.biz>]

I have two book author names marked up in <authorgroup>:

<authorgroup role="leadauthor">
                                    <author>
                                                <personname><honorific>Mr</honorific><firstname>John</firstname><surname>Smith</surname></personname>
                                                <contrib>Lead author contribution</contrib>
                                                <affiliation>
                                                            <shortaffil>Short affil.</shortaffil>
                                                            <jobtitle>Job title</jobtitle>
                                                            <orgname>Organisational affiliation</orgname>
                                                            <orgdiv>Org div</orgdiv>
                                                            <address>Org address</address>
                                                </affiliation>
                                    </author>
                                    <author>
                                                <personname>Name of second lead author</personname>
                                    </author>
                        </authorgroup>

 

My first issue is trying to generate both <author> names in separate meta elements in HTML5 using 1.78.1-ns. This is all I get:

<meta name="dcterms:creator" content="Smith, John" />

I have a customization that generates only the first author’s names (firstname and surname) – I don’t get the second author, nor do I get any content inside only <personname> (so far I need both <firstname> and <surname> to generate content):

<xsl:template name="user.head.content">
    <xsl:param name="node" select="."/>
    <xsl:variable name="info" select="(d:info)[1]"/>

…

<xsl:if test="$info and $info//d:author[ancestor::d:authorgroup[@role='leadauthor']]">     
      <meta name="dcterms:creator">
          <xsl:attribute name="content">
            <!--<xsl:call-template name="person.name.last-first">
            <xsl:with-param name="node" select="."/>
          </xsl:call-template>-->
             
            <xsl:choose>
              <xsl:when test="descendant::d:surname">
                <xsl:value-of select="normalize-space(string($info/d:authorgroup[@role='leadauthor']/d:author/d:personname/d:surname))"/>
                <xsl:text>, </xsl:text>
                <xsl:value-of select="normalize-space(string($info/d:authorgroup[@role='leadauthor']/d:author/d:personname/d:firstname))"/>
              </xsl:when>
              <xsl:otherwise>
                <xsl:value-of select="normalize-space(string($info/d:authorgroup[@role='leadauthor']/d:author/d:personname))"/>   
              </xsl:otherwise>
            </xsl:choose>
          </xsl:attribute> 
      </meta>
     
    </xsl:if>

…

</xsl:template>

 

I tried using xsl:for-each around the <meta> coding, and then again inside <meta>, but that generates the first author’s name multiple times in one <meta> element. I can’t see any clues from the EPUB metadata stylesheets either.

So: (1) How do I generate one meta element *for each author*, and (2) What coding works to generate content marked up in <personname> only (i.e. no child elements)?

--
Dave Gardiner