Re: [docbook-apps] Alt text not appearing in inlinemediaobject

[Thomas Schraitle <tom_schr@web.de>]

Hi David,

Am Dienstag, 29. Oktober 2013, 11:52:20 schrieb David Goss:
> I have the the following docbook 5 markup:
> <para>Click the
> <guibutton><inlinemediaobject><alt>Execute</alt><imageobject><imagedata
> fileref="img/ldms/ldms_button_execute.png"
> depth="1em"/></imageobject></inlinemediaobject> button.</guibutton></para>
> 
> It is outputting the following HTML :
> <p>Click the <span class="guibutton"><span class="inlinemediaobject"><img
> src="img/ldms/ldms_button_execute.png" height="13"></span></span>
> button.</p>
>
> I'm not sure why the alt text is not carrying over. Am I using the alt tag
> incorrectly or is this a bug? I'm using webhelp docbook-xsl-ns-1.78.1 .
 
Your DocBook markup is perfectly correct. But it seems, there is a deficiancy 
about the handling of inlinemediaobject in the DocBook stylesheets.

I suspect the html/graphics.xsl file in the "imagedata" template (lines 1250 - 
1331). In this template rule, the "process.image" template is called and the 
"alt" parameter is passed. However, it is not checked against an 
inlinemediaobject with a possible alt element. 

I would propose this change:

 <xsl:call-template name="process.image">
   <xsl:with-param name="alt">
     <xsl:choose>
       <xsl:when test="ancestor::mediaobject/alt">
          <xsl:apply-templates select="ancestor::mediaobject/alt"/>
       </xsl:when>
       <xsl:when test="ancestor::inlinemediaobject/alt">
          <xsl:apply-templates select="ancestor::inlinemediaobject/alt"/>
       </xsl:when>
       <xsl:otherwise>
          <xsl:apply-templates 
               select="$phrases[not(@role) or @role!='tex'][1]"/>
       </xsl:otherwise>
     </xsl:choose>
   </xsl:with-param>
   <xsl:with-param name="longdesc">
     <xsl:call-template name="write.longdesc">
        <xsl:with-param name="mediaobject"
                        select="ancestor::imageobject/parent::*"/>
     </xsl:call-template>
   </xsl:with-param>
 </xsl:call-template>


If you would like to give it a try, do the following:

1. Create a customization layer if you haven't done yet. If you don't know
   how, read one of the following URLs:
   http://www.sagehill.net/docbookxsl/CustomMethods.html#CustomizationLayer
   http://doccookbook.sf.net/html/en/dbc.common.dbcustomize.html

2. Copy the "imagedata" template from the original html/graphics.xsl template
   into your customization layer.

3. Search for the xsl:call-template line and apply the above "patch" (add the
   2nd xsl:when test).

4. Transform your DocBook document and use your customization layer.


> I did see this page in the XSL Guide:
> http://www.sagehill.net/docbookxsl/AltText.html
> But it looks to be for Docbook4.

You can use this also in DocBook 5 as long as it is valid.


-- 
Gruß/Regards
  Thomas Schraitle