custom.css.source — Name of a custom CSS input file
The custom.css.source
parameter enables you to add CSS styles to DocBook's
HTML output.
The parameter
specifies the name of a file containing custom
CSS styles. The file must be a well-formed XML file that
consists of a single style root
element that contains CSS styles as its text content.
For example:
<?xml version="1.0"?>
<style>
h2 {
font-weight: bold;
color: blue;
}
...
</style>
The filename specified by the parameter
should have a .xml
filename suffix, although that is not required.
The default value of this parameter is blank.
If custom.css.source is not blank, then
the stylesheet takes the following actions.
These actions take place regardless of the value of
the make.clean.html parameter.
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 custom.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 this external CSS stylesheet.
For example:
<link rel="stylesheet" href="custom.css" type="text/css">
If the make.clean.html parameter is nonzero
(the default is zero),
and if the docbook.css.source parameter
is not blank (the default is not blank),
then the stylesheet will also generate a default CSS file
and add a link tag to reference it.
The link to the custom CSS comes after the
link to the default, so it should cascade properly
in most browsers.
If you do not want two link tags, and
instead want your custom CSS to import the default generated
CSS file, then do the following:
Add a line like the following to your custom CSS source file:
@import url("docbook.css")
Set the docbook.css.link parameter
to zero. This will omit the link tag
that references the default CSS file.
If you set make.clean.html to nonzero but
you do not want the default CSS generated, then also set
the docbook.css.source parameter to blank.
Then no default CSS will be generated, and so
all CSS styles must come from your 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.