Apply a Theme

After creating a theme, you’ll need to tell Asciidoctor PDF where to find it. This is done using AsciiDoc attributes.

Theme and font directories

There are three AsciiDoc attributes that tell Asciidoctor PDF how to locate and apply your theme.

pdf-theme: The name or file path of the theme to load. Can be set using the --theme CLI option. When using JRuby, the file path may begin with uri:classloader: to reference a location on the classpath.

If the value of the pdf-theme attribute ends with .yml (e.g., custom-theme.yml), the name is assumed to be an absolute or relative file path. If the path is relative, it’s resolved starting from the value of the pdf-themesdir attribute. If the pdf-themesdir attribute is not specified, it is resolved from the current working directory instead.

If the value of the pdf-theme attribute doesn’t end with .yml (e.g., base), the suffix -theme.yml is automatically appended to build a valid absolute or relative file path (i.e., <name>-theme.yml). The value is then treated as a relative path (even if it’s absolute) and resolved starting from the value of the pdf-themesdir attribute. If the pdf-themesdir is not specified, the built-in themes directory is used as the starting point instead (rather than the current working directory).

You can use the {docdir} token as the first path segment in the name to build an absolute path starting from the directory of the source document.

The theme name or file path can be specified using the --theme CLI option as a shorthand.
pdf-themesdir: The directory path where the theme file is located. When using JRuby, the directory path may begin with uri:classloader: to reference a location on the classpath.

If the path is relative, the value is resolved starting from the current working directory. You can use the {docdir} token as the first path segment to build an absolute path starting from the directory of the source document.

If not specified, the value of this attribute will default to the absolute directory of the theme file (as specified by the pdf-theme attribute). If you want to use an ancestory directory instead, you must specify both the pdf-themesdir attribute and the pdf-theme attribute, and the pdf-theme attribute must be a path (at any depth) relative to the value of pdf-themesdir.

Relative image paths in your theme (such as image targets) are resolved starting from this location.
pdf-fontsdir: The directory path or paths where the fonts used by your theme, if any, are located. When using JRuby, each path may begin with uri:classloader: to reference a location on the classpath.

Multiple entries must be separated by either a comma or a semicolon. To reference a file inside a JAR file on the classpath, prefix with the path with uri:classloader: (JRuby only). If the path is relative, the value is resolved starting from the current working directory.

You can use the {docdir} token as the first path segment to create an absolute path starting from the directory of the document.

Load a theme

Let’s assume that you’ve put your theme files inside a directory named resources with the following layout:

doc.adoc
resources/
  themes/
    basic-theme.yml
  fonts/
    roboto-normal.ttf
    roboto-italic.ttf
    roboto-bold.ttf
    roboto-bold_italic.ttf

Here’s the formal way of loading your theme when calling Asciidoctor PDF:

$ asciidoctor-pdf -a pdf-theme=basic -a pdf-themesdir=resources/themes -a pdf-fontsdir=resources/fonts doc.adoc

You can replace the pdf-theme attribute assignment with --theme, which does the same thing:

$ asciidoctor-pdf --theme basic -a pdf-themesdir=resources/themes -a pdf-fontsdir=resources/fonts doc.adoc

If all goes well, Asciidoctor PDF will convert your document without any errors or warnings.

You only need to specify the pdf-fontsdir if you’re using custom fonts in your theme. By default, pdf-fontsdir resolves to the directory of the bundled fonts.

You can skip setting the pdf-themesdir attribute by passing the relative path of your theme file to the theme option:

$ asciidoctor-pdf --theme resources/themes/basic-theme.yml -a pdf-fontsdir=resources/fonts doc.adoc

In this case, the pdf-themesdir will be set automatically to the directory of the theme path specified either by the pdf-theme attribute or the --theme option (e.g., resources/themes in the previous example).

If a relative path is specified for pdf-themesdir or pdf-fontsdir, or pdf-theme when pdf-themesdir is not specified, that path is resolved starting from the current working directory. Alternately, you can use {docdir} as the first path segment to anchor them to the directory of the source document instead.

If you’re having difficulty getting the converter to locate your theme or fonts, you can specify absolute paths instead, which are used as is.

$ asciidoctor-pdf --theme /path/to/resources/themes/basic-theme.yml -a pdf-fontsdir=/path/to/resources/fonts doc.adoc

Relative font paths in the theme are resolved starting from the directory resolved from the pdf-fontsdir attribute. All other paths in the theme are resolved starting from the value of the pdf-themesdir attribute. You can prefix paths in the theme using the {docdir} or {docimagesdir} attribute references.

Using Maven and Gradle

As usual, you can also use build tools like Maven and Gradle to build a themed PDF. The only thing you need to add to an existing build is the attributes mentioned above.

Speaking of Java, you can bundle and distribute your theme and fonts in a jar file. To reference the theme file and/or directory of fonts from inside the jar, refer to their location on the classpath using the uri:classloader: prefix. Here’s how you’d load both the theme and fonts from the classpath:

$ asciidoctorj -b pdf --theme uri:classloader:/path/to/themes/my-theme.yml -a pdf-fontsdir=uri:classloader:/path/to/fonts document.adoc

This only works when running Asciidoctor PDF with JRuby (i.e., on the JVM).