$mediaobject-accessibility

$mediaobject-accessibility — Accessibility settings for media objects.

Parameter:

{}mediaobject-accessibility

Defined in:

param.xsl

Used in:

param.xsl, modules/variable.xsl

Synopsis

  |$mediaobject-accessibility as xs:string := 'summary details'

Description

The $mediaobject-accessibility parameter determines how accessibility features are added to media objects (image, video, and audio elements).

The value of this parameter is a space-separated list of strings. If the list contains:

summary: A summary attribute will be added if there is an alt element or a textobject containing a single phrase is available.
details: A details element will be added to the div that surrounds the image if there is a textobject containing anything other than a single phrase available.
a11y-metadata: Metadata will be provided using the conventions described in EPUB Accessibility.

The list may contain either or both values. If other values are present, they are ignored.

See Example 1, “An example of media object accessibility”.

   |<mediaobject>
   |   <alt>This is a skeuomorphic “postage stamp” with the
   |DocBook logo.</alt>
   |   <imageobject>
   |      <imagedata fileref="media/stamp400x256.png"/>
   |   </imageobject>
   |   <textobject>
   |      <para>This is a skeuomorphic image of a “postage
   |stamp.” Centrally, it features the DocBook wood
   |duck logo. the word “DocBook” appears on the left
   |hand side, rotated 90° counter-clockwise. The
   |DocBook tag line, “The Source for Documentation”
   |is printed in the upper-right corner.
   |</para>
   |   </textobject>
   |</mediaobject>

Example 1. An example of media object accessibility

One possible rendering of such an example:

This is a skeuomorphic image of a “postage stamp.” Centrally, it features the DocBook wood duck logo. the word “DocBook” appears on the left hand side, rotated 90° counter-clockwise. The DocBook tag line, “The Source for Documentation” is printed in the upper-right corner.

Inspection of the HTML will reveal that the summary attribute is present on the div that wraps the figure and a details element precedes the image. These may or may not be rendered by your user agent depending on its accessibility features and settings.