$fallback-js
$fallback-js — Script to support audio/video fallback.
Parameter:
{}fallback-js
Defined in:
param.xsl
Used in:
main.xsl, param.xsl
Synopsis
|$fallback-js := 'js/fallback.js'
Description
Apparently, there’s no declarative way to offer an HTML fallback message when all of the audio or video sources in a media object are unusable. Instead, it has to be done with JavaScript.
This parameter identifies the JavaScript file to load for this support.
It must define a global function named docbook_object_fallback
that takes the source node as a paramter.
To disable fallback, set this parameter to the empty sequence or the empty string.
Place this script in the
head
of the document
and do not defer loading it.