Z3986 Issues Detail

Change content model for the showin attribute

Submitted By:   Per Sennels

Status:   Resolved

Issue Type:   DTD

Assigned To:   DTD Team

Issue Description:   

That the content model for the showin attribute is changed from showin (xxx|xxp|xlx|xlp|bxx|bxp|blx|blp) #IMPLIED to showin CDATA #IMPLIED

Reason: The current content model is associated with the traditional formats for the visually impaired user, which makes the showin attribute unsuitable for other formats, e.g. ebooks, audio etc. With the proposed change, the values showin="audio-synth-speech" showin="audio-human-speech" showin="ebook-html ebook-rtf" showin="audio braille large-print" showin="pdf" showin="latex" showin="pda" etc, etc would be available. Certainly, main stream publishers would benefit from a less restricted model for the showin attribute. It would also be possible to localize the attribute values, some examples in Norwegian could be showin="lydbok" showin="punkt" etc The disadvantage is that mark-up would be less predictable. However, with the upcoming XSLT 2.0 specifications this should not be a problem during transformation. The template below is an example of how selection based on the showin attribute could be done:

  <xml:space="preserve">
<xsl:template match="*[@showin]" priority="10"> 
<xsl:param name="output-format"; as="xs:string" select="'_UNDEF'" tunnel="yes" /> 
 <xsl:choose 
  <xsl:when test="not(matches(@showin,$output-format))"> 
    <xsl:comment> 
       The element <xsl:value-of select="name()" /> has been removed. 
    </xsl:comment>
  </xsl:when>
  <xsl:otherwise>
   <xsl:next-match />
  </xsl:otherwise>
 </xsl:choose>
</xsl:template>

This Issue Has Been Resolved as an Errata

Agreed Solution:

No changes to the showin attribute. The showin attribute is being marked as deprecated in the 2005-2 version of the DTBook DTD. Following more modern conventions that have evolved since showin was added some years ago, the committee's intention is for output format-specific information to be maintained in separate namespaces, a.k.a. extension modules.

For resolution details go to the Errata page.