generating meta attributes for epub

When transforming using DocBook 1.76.1-ns stylesheets to epub, I need to generate meta tags for DC.identifier.

The XML book file has, immediately inside an info element:

I need to generate a separate meta element for each and every biblioid using a variation of Dublin Core, such that for the ISBN I want the meta element to appear with an additional “scheme” attribute within the XHTML <head> as:

The scheme attribute is derived from the biblioid class attribute.

I’ve tried to modify the head.content template with this code (which sits inside the code beginning with <xsl:if test="$generate.meta.abstract != 0">):

<xsl:if test="$info and $info/d:biblioid">
                <meta name = "DCTERMS.identifier">
                    <xsl:if test="@class='doi'">
                        <xsl:attribute name="scheme">
                            <xsl:text> DCTERMS.DOI</xsl:text>
                        </xsl:attribute>
                        <xsl:attribute name="content">
                            <xsl:for-each select="$info/d:biblioid[@class='doi']">
                                <xsl:value-of select="normalize-space(.)"/>
                                <xsl:if test="position() < last()" >
                                    <xsl:text> </xsl:text>
                                </xsl:if>
                            </xsl:for-each>
                        </xsl:attribute>
                    </xsl:if>
                    <xsl:if test="@class='isbn'">
                        <xsl:attribute name="scheme">
                            <xsl:text> DCTERMS.ISBN</xsl:text>
                        </xsl:attribute>
                        <xsl:attribute name="content">
                            <xsl:for-each select="$info/d:biblioid[@class='isbn']">
                                <xsl:value-of select="normalize-space(.)"/>
                                <xsl:if test="position() < last()" >
                                    <xsl:text> </xsl:text>
                                </xsl:if>
                            </xsl:for-each>
                        </xsl:attribute>
                    </xsl:if>
                    <xsl:if test="@class='issn'">
                        <xsl:attribute name="scheme">
                            <xsl:text> DCTERMS.ISSN</xsl:text>
                        </xsl:attribute>
                        <xsl:attribute name="content">
                            <xsl:for-each select="$info/d:biblioid[@class='issn']">
                                 <xsl:value-of select="normalize-space(.)"/>
                                <xsl:if test="position() < last()" >
                                    <xsl:text> </xsl:text>
                                </xsl:if>
                            </xsl:for-each>
                        </xsl:attribute>
                    </xsl:if>
                </meta>
            </xsl:if>

All I get is a meta tag with nothing after the meta name:

Can you please suggest better logic.

Thanks,

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