alt text dropped in FO/PDF output of DocBook XML

[amsimms]

We include alt-text whenever we include images via "mediaobject"--this is a requirement for 508 compliance. Here is an example:

<mediaobject>
<alt>Department of Veteran's Affairs Logo</alt>
<imageobject>
<imagedata contentwidth="2in"
align="center"
fileref="images/va-logo.png"
format="png"/>
</imageobject>
</mediaobject>


However, the alt text entries are stripped in the resulting FO output despite running with <accessibility>true</accessibility> set in fo.conf. I doubt we're the first ones to encounter this issue--is there a parameter that needs to be set in order for alt text to be inserted into the resulting FO output?

[Radu]

Hi,

It seems that the default XSLT stylesheet provided by the Docbook project to convert Docbook to PDF does not use the <alt> element for anything.
I added an issue for it here:

https://github.com/docbook/xslt10-stylesheets/issues/62

if you want to try a manual XSLT fix, in the XSLT stylesheet:

OXYGEN_INSTALL_DIR\frameworks\docbook\xsl\fo\graphics.xsl

there is an xsl:if like:

Code: Select all

    <xsl:if test="$align != ''">

      <xsl:attribute name="text-align">

        <xsl:value-of select="$align"/>

      </xsl:attribute>

    </xsl:if>

After it you can add a:

Code: Select all

    <xsl:if test="parent::d:imageobject/preceding-sibling::d:alt">

      <xsl:attribute name="alt-text" namespace="http://xmlgraphics.apache.org/fop/extensions">

        <xsl:value-of select="parent::d:imageobject/preceding-sibling::d:alt"/>

      </xsl:attribute>

    </xsl:if>

Regards,
Radu