docbook.css.source — Name of the default CSS input file
The docbook.css.source parameter
specifies the name of the file containing the default DocBook
CSS styles. Those styles are necessary when the
make.clean.html parameter is nonzero.
The file is a well-formed XML file that
must consist of a single style root
element that contains CSS styles as its text content.
The default value of the parameter (and filename)
is docbook.css.xml.
The stylesheets ship with the default file. You can substitute
your own and specify its path in this parameter.
If docbook.css.source is not blank,
and make.clean.html is nonzero, then
the stylesheet takes the following actions:
The stylesheet uses the XSLT document()
function to open the file specified by the parameter and
load it into a variable.
The stylesheet forms an output pathname consisting of the
value of the base.dir parameter (if it is set)
and the value of docbook.css.source,
with the .xml suffix stripped off.
The stylesheet removes the style
wrapper element and writes just the CSS text content to the output file.
The stylesheet adds a link element to the
HTML HEAD element to reference the external CSS stylesheet.
For example:
<link rel="stylesheet" href="docbook.css" type="text/css">
However, if the docbook.css.link
parameter is set to zero, then no link is written
for the default CSS file. That is useful if a custom
CSS file will import the default CSS stylesheet to ensure
proper cascading of styles.
If the docbook.css.source parameter
is changed from its default docbook.css.xml to blank,
then no default CSS is generated. Likewise if the
make.clean.html parameter is set to zero,
then no default CSS is generated. The
custom.css.source parameter can be used
instead to generate a complete custom CSS file.
You can use the generate.css.header
parameter to instead write the CSS to each HTML HEAD
element in a style tag instead of an external CSS file.