The theming system in Asciidoctor PDF is used to control the layout and styling of the PDF file that Asciidoctor PDF generates from AsciiDoc. The theme is driven by a YAML-based configuration file. This document explains how the theming system works, how to define a custom theme and how to enable the theme when running Asciidoctor PDF.
The theme language in Asciidoctor PDF is based on the YAML data format and incorporates many concepts from CSS and SASS. Therefore, if you have a background in web design, the theme language should be immediately familiar to you.
Like CSS, themes have both selectors and properties.
Selectors are the component you want to style.
The properties are the style elements of that component that can be styled.
All selector names are implicit (e.g., heading), so you customize the theme primarily by manipulating pre-defined property values (e.g., font_size).
|
Note
|
The theme language in Asciidoctor PDF supports a limited subset of the properties from CSS. Some of these properties have different names from those found in CSS.
|
A theme (or style) is described in a YAML-based data format and stored in a dedicated theme file. YAML is a human-friendly data format that resembles CSS and helps to describe the theme. The theme language adds some extra features to YAML, such as variables, basic math, measurements and color values. These enhancements will be explained in detail in later sections.
The theme file must be named <name>-theme.yml, where <name> is the name of the theme.
Here’s an example of a basic theme file:
page:
layout: portrait
margin: [0.75in, 1in, 0.75in, 1in]
size: Letter
base:
font_color: #333333
font_family: Times-Roman
font_size: 12
line_height_length: 17
line_height: $base_line_height_length / $base_font_size
vertical_rhythm: $base_line_height_length
heading:
font_color: #262626
font_size: 17
font_style: bold
line_height: 1.2
margin_bottom: $vertical_rhythm
link:
font_color: #002FA7
outline_list:
indent: $base_font_size * 1.5When creating a new theme, you only have to define the keys you want to override from the base theme, which is loaded prior to loading your custom theme. The converter uses the information from the theme map to help construct the PDF. All the available keys are documented in Keys.
Keys may be nested to an arbitrary depth to eliminate redundant prefixes (an approach inspired by SASS). Once the theme is loaded, all keys are flattened into a single map of qualified keys. Nesting is simply a shorthand way of organizing the keys. In the end, a theme is just a map of key/value pairs.
Nested keys are adjoined to their parent key with an underscore (_).
This means the selector part (e.g., link) is combined with the property name (e.g., font_color) into a single, qualified key (e.g., link_font_color).
For example, let’s assume we want to set the base (i.e., global) font size and color. These keys may be written longhand:
base_font_color: #333333
base_font_family: Times-Roman
base_font_size: 12Or, to avoid having to type the prefix base_ multiple times, the keys may be written hierarchically:
base:
font_color: #333333
font_family: Times-Roman
font_size: 12Or even:
base:
font:
color: #333333
family: Times-Roman
size: 12Each level of nesting must be indented by twice the amount of indentation of the parent level. Also note the placement of the colon after each key name.
The value of a key may be one of the following types:
-
String
-
Font family name (e.g., Roboto)
-
Font style (normal, bold, italic, bold_italic)
-
Alignment (left, center, right, justify)
-
Color as hex string (e.g., #ffffff)
-
Image path
-
-
Number (integer or float) with optional units (default unit is points)
-
Array
-
Color as RGB array (e.g., [51, 51, 51])
-
Color CMYK array (e.g., [50, 100, 0, 0])
-
Margin (e.g., [1in, 1in, 1in, 1in])
-
Padding (e.g., [1in, 1in, 1in, 1in])
-
-
Variable reference (e.g., $base_font_color)
-
Math expression
Note that keys almost always require a value of a specific type, as documented in Keys.
Like CSS, inheritance is a key feature in the Asciidoctor PDF theme language. For many of the properties, if a key is not specified, the key inherits the value applied to the parent content in the content hierarchy. This behavior saves you from having to specify properties unless you want to override the inherited value.
The following keys are inherited:
-
font_family
-
font_color
-
font_size
-
font_style
-
line_height (currently some exceptions)
-
text_transform (only for headings)
-
margin_bottom (falls back to $vertical_rhythm)
Headings are special in that they inherit starting from a specific heading level (e.g., heading_font_size_h2) to the heading category (e.g., heading_font_size) and then directly to the base value (e.g., base_font_size), skipping any enclosing context.
To save you from having to type the same value in your theme over and over, or to allow you to base one value on another, the theme language supports variables.
Variables consist of the key name preceded by a dollar ($) (e.g., $base_font_size).
Any qualified key that has already been defined can be referenced in the value of another key.
(In order words, as soon as the key is assigned, it’s available to be used as a variable).
For example, once the following line is processed,
base:
font_color: #333333the variable $base_font_color will be available for use in subsequent lines and will resolve to #333333.
Let’s say you want to make the font color of the sidebar title the same as the heading font color.
Just assign the value $heading_font_color to the $sidebar_title_font_color.
heading:
font_color: #191919
sidebar:
title:
font_color: $heading_font_colorYou can also use variables in math expressions to use one value to build another. This is commonly done to set font sizes proportionally. It also makes it easy to test different values very quickly.
base:
font_size: 12
font_size_large: $base_font_size * 1.25
font_size_small: $base_font_size * 0.85We’ll cover more about math expressions later.
You can define arbitrary key names to make custom variables.
This is one way to group reusable values at the top of your theme file.
If you are going to do this, it’s recommended that you organize the keys under a custom namespace, such as brand.
For instance, here’s how you can define your (very patriotic) brand colors:
brand:
red: #E0162B
white: #FFFFFF
blue: #0052A5You can now use these custom variables later in the theme file:
base:
font_color: $brand_blueThe theme language supports basic math operations to support calculated values. The following table lists the supported operations and the corresponding operator for each.
| Operation | Operator |
|---|---|
multiply |
* |
divide |
/ |
add |
+ |
subtract |
- |
|
Note
|
Like programming languages, multiple and divide take precedence over add and subtract. |
The operator must always be surrounded by a space on either side. Here’s an example of a math expression with fixed values.
conum:
line_height: 4 / 3Variables may be used in place of numbers anywhere in the expression:
base:
font_size: 12
font_size_large: $base_font_size * 1.25Values used in a math expression are automatically coerced to a float value before the operation. If the result of the expression is an integer, the value is coerced to an integer afterwards.
|
Important
|
Numeric values less than 1 must have a 0 before the decimal point (e.g., 0.85). |
The theme language also supports several functions for rounding the result of a math expression. The following functions may be used if they surround the whole value or expression for a key.
- round(…)
-
Rounds the number to the nearest half integer.
- floor(…)
-
Rounds the number up to the next integer.
- ceil(…)
-
Rounds the number down the previous integer.
You might use these functions in font size calculations so that you get more exact values.
base:
font_size: 12.5
font_size_large: ceil($base_font_size * 1.25)Several of the keys require a value in points (pt), the unit of measure for the PDF canvas. A point is defined as 1/72 of an inch. However, us humans like to think in real world units like inches (in), centimeters (cm) or millimeters (mm). You can let the theme do this conversion for you automatically by adding a unit notation next to any number.
The following units are supported:
| Unit | Suffix |
|---|---|
Inches |
in |
Centimeter |
cm |
Millimeter |
mm |
Points |
pt |
Here’s an example of how you can use inches to define the page margins:
page:
margin: [0.75in, 1in, 0.75in, 1in]The order of elements in a measurement array is the same as it is in CSS:
-
top
-
right
-
bottom
-
left
The theme language supports color values in three formats:
- Hex
-
A string of 3 or 6 characters with an optional leading
#.The special value
transparentindicates that a color should not be used. - RGB
-
An array of numeric values ranging from 0 to 255.
- CMYK
-
An array of numeric values ranging from 0 to 1 or from 0% to 100%.
The hex color value is likely most familiar to web developers.
The value must be either 3 or 6 characters (case insensitive) with an optional leading hash (#).
The following are all equivalent values for the color red:
f00 |
#f00 |
ff0000 |
#ff0000 |
F00 |
#F00 |
FF0000 |
#FF0000 |
Here’s how a hex color value appears in the theme file:
base:
font_color: #ff0000It’s also possible to specify no color by assigning the special value transparent as shown here:
base:
background_color: transparentAn RGB array value must be three numbers ranging from 0 to 255. The values must be separated by commas and be surrounded by square brackets.
|
Note
|
An RGB array is automatically converted to a hex string internally, so there’s no difference between ff0000 and [255, 0, 0]. |
Here’s how to specify the color red in RGB:
-
[255, 0, 0]
Here’s how a RGB color value appears in the theme file:
base:
font_color: [255, 0, 0]A CMYK array value must be four numbers ranging from 0 and 1 or from 0% to 100%. The values must be separated by commas and be surrounded by square brackets.
Unlike the RGB array, the CMYK array is not converted to a hex string internally. PDF has native support for CMYK colors, so you can preserve the original color values in the final PDF.
Here’s how to specify the color red in CMYK:
-
[0, 0.99, 1, 0]
-
[0, 99%, 100%, 0]
Here’s how a CMYK color value appears in the theme file:
base:
font_color: [0, 0.99, 1, 0]An image is specified either as a bare image path or as an inline image macro as found in the AsciiDoc syntax.
Images are currently resolved relative to the value of the pdf-stylesdir attribute.
The following image types (and corresponding file extensions) are supported:
-
PNG (.png)
-
JPEG (.jpg)
-
SVG (.svg)
|
Caution
|
The GIF format (.gif) is not supported. |
Here’s how an image is specified in the theme file as a bare image path:
title_page:
background_image: title-cover.pngHere’s how the image is specified using the inline image macro:
title_page:
background_image: image:title-cover.png[]Like in the AsciiDoc syntax, the inline image macro allows you to supply set the width of the image and the alignment:
title_page:
logo_image: image:logo.png[width=250,align=center]You can select from built-in PDF fonts, fonts bundled with Asciidoctor PDF or custom fonts loaded from TrueType font (TTF) files. If you want to use custom fonts, you must first declare them in your theme file.
The names of the built-in fonts (for general-purpose text) are as follows:
| Font Name | Font Family |
|---|---|
Helvetica |
sans-serif |
Times-Roman |
serif |
Courier |
monospace |
Using a built-in font requires no additional files.
You can use the key anywhere a font_family property is accepted in the theme file.
For example:
base:
font_family: Times-RomanHowever, when you use a built-in font, the characters that you use in your document are limited to the characters in the WINANSI (Windows-1252) code set. WINANSI includes most of the characters needed for writing in Western languages (English, French, Spanish, etc). For anything outside of that, PDF is BYOF (Bring Your Own Font).
Even though the built-in fonts require the content to be encoded in WINANSI, you still type your AsciiDoc document in UTF-8. Asciidoctor PDF encodes the content into WINANSI when building the PDF.
If you’re using Prawn 1.3.0 with one of the built-in fonts, any characters in your AsciiDoc document that cannot be encoded to WINANSI will be replaced with an underscore glyph (_).
If you’re using Prawn 2.0.0 or above with one of the built-in fonts, if your AsciiDoc document contains a character that cannot be encoded to WINANSI, a warning will be issued and conversion will halt.
For more information about how Prawn handles character encodings for built-in fonts, see this note in the Prawn CHANGELOG.
Asciidoctor PDF bundles several fonts that are used in the default theme. You can also use these fonts in your custom theme. These fonts provide more characters than the built-in PDF fonts, but still only a subset of UTF-8.
The family name of the fonts bundled with Asciidoctor PDF are as follows:
- Noto Serif
-
A serif font that can be styled as normal, italic, bold or bold_italic.
- M+ 1mn
-
A monospaced font that maps different thicknesses to the styles normal, italic, bold and bold_italic. Also provides the circuled numbers used in callouts.
- M+ 1p Fallback
-
A sans-serif font that provides a very complete set of Unicode glyphs. Cannot be styled as italic, bold or bold_italic. Useful as a fallback font.
|
Caution
|
At the time of this writing, you cannot use the bundled fonts if you define your own custom fonts. This limitation may be lifted in the future. |
The limited character set of WINANSI, or the bland look of the built-in fonts, may motivate you to load your own font. Custom fonts can enhance the look of your PDF theme substantially.
To start, you need to find a collection of TTF file of the font you want to use. A collection typically consists of all four styles of a font:
-
normal
-
italic
-
bold
-
bold_italic
You’ll need all four styles to support AsciiDoc content properly. Asciidoctor PDF cannot italicize a font that is not italic like a browser can.
Once you’ve obtained the TTF files, put them into a directory in your project where you want to store the fonts. It’s recommended that you name them consistently so it’s easier to type the names in the theme file.
Let’s assume the name of the font is Roboto. Name the files as follows:
-
roboto-normal.ttf (originally Roboto-Regular.ttf)
-
roboto-italic.ttf (originally Roboto-Italic.ttf)
-
roboto-bold.ttf (originally Roboto-Bold.ttf)
-
roboto-bold_italic.ttf (originally Roboto-BoldItalic.ttf)
Next, declare the font under the font_catalog key at the top of your theme file, giving it a unique key (e.g., Roboto).
font:
catalog:
Roboto:
normal: roboto-normal.ttf
italic: roboto-italic.ttf
bold: roboto-bold.ttf
bold_italic: roboto-bold_italic.ttfYou can use the key you gave to the font in the font catalog anywhere a font_family property is accepted in the theme file.
For instance, to use the Roboto font for all headings, you’d use:
heading:
font_family: RobotoWhen you execute Asciidoctor PDF, you need to specify the directory where the fonts reside using the pdf-fontsdir attribute:
$ asciidoctor-pdf -a pdf-style=basic-theme.yml -a pdf-fontsdir=path/to/fonts document.adoc
|
Warning
|
Currently, all fonts referenced by the theme need to be present in the directory specified by the pdf-fontsdir attribute.
|
You can add any number of fonts to the catalog. Each font must be assigned a unique key, as shown here:
font:
catalog:
Roboto:
normal: roboto-normal.ttf
italic: roboto-italic.ttf
bold: roboto-bold.ttf
bold_italic: roboto-bold_italic.ttf
Roboto Light:
normal: roboto-light-normal.ttf
italic: roboto-light-italic.ttf
bold: roboto-light-bold.ttf
bold_italic: roboto-light-bold_italic.ttf|
Tip
|
Text in SVGs will use the font catalog from your theme. We recommend that you match the font key to the name of the font seen by the operating system. This will allow you to use the same font names (aka families) in both your graphics program and Asciidoctor PDF. |
If one of your fonts is missing a character that is used in a document, such as special symbols, you can tell Asciidoctor PDF to retrieve the character from a fallback font. You only need to specify one fallback font…typically one that has a full set of symbols.
Like with other custom fonts, you first need to declare the fallback font. Let’s choose Droid Sans Fallback. You can map all the styles to a single font file (since bold and italic don’t usually make sense for symbols).
font:
catalog:
Roboto:
normal: roboto-normal.ttf
italic: roboto-italic.ttf
bold: roboto-bold.ttf
bold_italic: roboto-bold_italic.ttf
DroidSansFallback:
normal: droid-sans-fallback.ttf
italic: droid-sans-fallback.ttf
bold: droid-sans-fallback.ttf
bold_italic: droid-sans-fallback.ttfNext, assign the key to the fallbacks key under the font_catalog key.
Be sure to surround the key name in square brackets as shown below.
font:
catalog:
Roboto:
normal: roboto-normal.ttf
italic: roboto-italic.ttf
bold: roboto-bold.ttf
bold_italic: roboto-bold_italic.ttf
DroidSansFallback:
normal: droid-sans-fallback.ttf
italic: droid-sans-fallback.ttf
bold: droid-sans-fallback.ttf
bold_italic: droid-sans-fallback.ttf
fallbacks: [DroidSansFallback]|
Tip
|
If you are using more than one fallback font, separate each key name by a comma. |
That’s it! Now you’re covered. You don’t need to reference the fallback font anywhere else in your theme file to use it.
|
Caution
|
Using a fallback font does slow down PDF generation slightly. It’s best to select fonts that have all the characters you need. |
TBW
| Key | Value Type | Example |
|---|---|---|
page_background_color[1] |
|
|
page_background_image[1] |
path (absolute or relative to pdf-stylesdir) |
|
page_layout |
portrait, landscape |
|
page_margin |
|
|
page_size |
named size, measurement array [width, height] |
|
[1] Page background colors and images do not currently work when using AsciidoctorJ PDF. This limitation is due to a bug in Prawn 1.3.1. The limitation will remain until AsciidoctorJ PDF upgrades to Prawn 2.x (an upgrade that is waiting on AsciidoctorJ to migrate to JRuby 9000). For more details, see this thread.
| Key | Value Type | Example |
|---|---|---|
base_font_color |
|
|
base_font_family |
|
|
base_font_size |
|
|
base_line_height_length[1] |
|
|
base_line_height[1] |
|
|
base_font_size_large |
|
|
base_font_size_small |
|
|
base_font_style |
normal, italic, bold, bold_italic |
|
base_align |
left, center, right, justify |
|
base_border_radius |
|
|
base_border_width |
|
|
base_border_color |
|
[1] You should set either line_height or line_height_length and derive the value of the other using a calculation since these are correlated values.
For instance, if you set line_height_length, then use line_height: $base_line_height_length / $base_font_size to define the line height.
| Key | Value Type | Example |
|---|---|---|
vertical_rhythm |
|
|
horizontal_rhythm |
|
|
Note
|
Vertical and horizontal rhythm are used for vertical and horizontal spacing, respectively, when there a specific theme key is not defined for a certain purpose. These keys predated the CSS-style theme system and are planned to be phased out. |
| Key | Value Type | Example |
|---|---|---|
link_font_color |
|
|
link_font_family |
|
|
link_font_size |
|
|
link_font_style |
normal, italic, bold, bold_italic |
|
The literal key is used for inline monospaced text in prose and table cells.
| Key | Value Type | Example |
|---|---|---|
literal_font_color |
|
|
literal_font_family |
|
|
literal_font_size |
|
|
literal_font_style |
normal, italic, bold, bold_italic |
|
| Key | Value Type | Example |
|---|---|---|
heading_font_color |
|
|
heading_font_family |
|
|
heading_font_size |
|
|
heading_font_style |
normal, italic, bold, bold_italic |
|
heading_h<n>_font_color[1] |
|
|
heading_h<n>_font_family[1] |
|
|
heading_h<n>_font_size[1] |
|
|
heading_h<n>_font_style[1] |
normal, italic, bold, bold_italic |
|
heading_line_height |
|
|
heading_margin_top |
|
|
heading_margin_bottom |
|
[1] <n> may be a number ranging from 1 to 6, representing each of the six heading levels.
| Key | Value Type | Example |
|---|---|---|
title_page_align |
left, center, right, justify |
|
title_page_background_color[1] |
|
|
title_page_background_image[1] |
path (absolute or relative to pdf-stylesdir) |
|
title_page_logo_align |
left, center, right |
|
title_page_logo_image |
inline image macro |
|
title_page_logo_top |
percentage |
|
title_page_title_top |
percentage |
|
title_page_title_font_size |
|
|
title_page_title_font_color |
|
|
title_page_title_line_height |
|
|
title_page_subtitle_font_size |
|
|
title_page_subtitle_font_style |
normal, italic, bold, bold_italic |
|
title_page_subtitle_line_height |
|
|
title_page_authors_margin_top |
|
|
title_page_authors_font_size |
|
|
title_page_authors_font_color |
|
|
title_page_revision_margin_top |
|
|
Tip
|
The title page can be disabled from the document by setting the notitle attribute in the document header.
|
[1] Background colors and images do not currently work when using AsciidoctorJ PDF. This limitation is due to a bug in Prawn 1.3.1. The limitation will remain until AsciidoctorJ PDF upgrades to Prawn 2.x (an upgrade that is waiting on AsciidoctorJ to migrate to JRuby 9000). For more details, see this thread.
| Key | Value Type | Example |
|---|---|---|
block_padding |
|
|
block_margin_top |
|
|
block_margin_bottom |
|
Block styles are applied to the following block types:
|
|
|
| Key | Value Type | Example |
|---|---|---|
caption_font_color |
|
|
caption_font_family |
|
|
caption_font_size |
|
|
caption_font_style |
normal, italic, bold, bold_italic |
|
caption_align |
left, center, right, justify |
|
caption_margin_inside |
|
|
caption_margin_outside |
|
| Key | Value Type | Example |
|---|---|---|
code_font_color |
|
|
code_font_family |
|
|
code_font_size |
|
|
code_font_style |
normal, italic, bold, bold_italic |
|
code_padding |
|
|
code_line_height |
|
|
code_background_color |
|
|
code_border_color |
|
|
code_border_radius |
|
|
code_border_width |
|
| Key | Value Type | Example |
|---|---|---|
blockquote_font_color |
|
|
blockquote_font_family |
|
|
blockquote_font_size |
|
|
blockquote_font_style |
normal, italic, bold, bold_italic |
|
blockquote_border_width |
|
|
blockquote_border_color |
|
|
blockquote_cite_font_size |
|
|
blockquote_cite_font_color |
|
|
blockquote_cite_font_family |
|
|
blockquote_cite_font_style |
normal, italic, bold, bold_italic |
|
| Key | Value Type | Example |
|---|---|---|
sidebar_border_color |
|
|
sidebar_border_radius |
|
|
sidebar_border_width |
|
|
sidebar_background_color |
|
|
sidebar_padding |
|
|
sidebar_title_align |
left, center, right, justify |
|
sidebar_title_font_color |
|
|
sidebar_title_font_family |
|
|
sidebar_title_font_size |
|
|
sidebar_title_font_style |
normal, italic, bold, bold_italic |
|
| Key | Value Type | Example |
|---|---|---|
example_border_color |
|
|
example_border_radius |
|
|
example_border_width |
|
|
example_background_color |
|
| Key | Value Type | Example |
|---|---|---|
admonition_border_color |
|
|
admonition_border_width |
|
|
admonition_icon_<name>_name[1] |
string[2] |
|
admonition_icon_<name>_stroke_color |
|
|
admonition_icon_<name>_size |
number |
|
[1] <name> can be note, tip, warning, important or caution.
[2] See the .yml files in the prawn-icon repository for a list of valid names.
The prefix (e.g., fa-) determines which font set to use.
| Key | Value Type | Example |
|---|---|---|
lead_font_size |
|
|
lead_line_height |
|
| Key | Value Type | Example |
|---|---|---|
abstract_font_color |
|
|
abstract_font_size |
|
|
abstract_line_height |
|
|
abstract_font_style |
normal, italic, bold, bold_italic |
|
| Key | Value Type | Example |
|---|---|---|
thematic_break_border_color |
|
|
thematic_break_border_style |
solid, double, dashed, dotted |
|
thematic_break_border_width |
|
|
thematic_break_margin_top |
|
|
thematic_break_margin_bottom |
|
| Key | Value Type | Example |
|---|---|---|
description_list_term_font_style |
normal, italic, bold, bold_italic |
|
description_list_description_indent |
|
| Key | Value Type | Example |
|---|---|---|
outline_list_indent |
|
|
outline_list_item_spacing |
|
| Key | Value Type | Example |
|---|---|---|
table_background_color |
|
|
table_head_background_color |
|
|
table_even_row_background_color |
|
|
table_foot_background_color |
|
|
table_header_cell_align |
left, center, right |
|
table_header_cell_background_color |
|
|
table_header_cell_font_color |
|
|
table_header_cell_font_family |
|
|
table_header_cell_font_size |
|
|
table_header_cell_font_style |
normal, italic, bold, bold_italic |
|
table_border_color |
|
|
table_border_width |
|
|
table_cell_padding |
|
| Key | Value Type | Example |
|---|---|---|
toc_dot_leader_content |
double-quoted string |
|
toc_dot_leader_color |
|
|
toc_font_color |
|
|
toc_h<n>_font_color |
|
|
toc_font_family |
|
|
toc_font_size |
|
|
toc_font_style |
normal, italic, bold, bold_italic |
|
toc_line_height |
number |
|
toc_indent |
|
|
toc_margin_top |
|
| Key | Value Type | Example |
|---|---|---|
header_background_color |
|
|
header_border_color |
|
|
header_border_style |
solid, double, dashed, dotted |
|
header_border_width |
|
|
header_font_color |
|
|
header_font_family |
|
|
header_font_size |
|
|
header_font_style |
normal, italic, bold, bold_italic |
|
header_height |
|
|
header_line_height |
number |
|
header_padding |
|
|
header_image_vertical_align |
top, middle, bottom, measurement |
|
header_vertical_align |
top, middle, bottom |
|
header_<side>_content_<align>[1] |
quoted string |
|
footer_background_color |
|
|
footer_border_color |
|
|
footer_border_style |
solid, double, dashed, dotted |
|
footer_border_width |
|
|
footer_font_color |
|
|
footer_font_family |
|
|
footer_font_size |
|
|
footer_font_style |
normal, italic, bold, bold_italic |
|
footer_height |
|
|
footer_line_height |
number |
|
footer_padding |
|
|
footer_image_vertical_align |
top, middle, bottom, measurement |
|
footer_vertical_align |
top, middle, bottom |
|
footer_<side>_content_<align>[1] |
quoted string |
|
[1] <side> can be recto (odd pages) or verso (even pages).
<align> can be left, center or right.
|
Important
|
You must define a height for the running header or footer, respectively, or it will not be shown. |
|
Tip
|
The running header and footer can be disabled from the document by setting the noheader and the nofooter attributes, respectively, in the document header.
|
|
Note
|
If content is not specified for the running footer, the page number (i.e., {page-number}) will be shown on the left side on verso pages and the right side on recto pages.
|
|
Note
|
The background color spans the width of the page. When a background color is specified, the border also spans the width of the page. |
You can use any attribute defined in your AsciiDoc document in the content of the running header and footer. In addition, the following attributes are also available when defining the content keys in the footer:
-
page-count
-
page-number
-
document-title
-
document-subtitle
-
chapter-title
-
section-title
-
section-or-chapter-title
You can also built-in AsciiDoc text replacements like (C) or numeric character references like ©.
Here’s an example that shows how attributes and replacements can be used in the running footer:
header:
height: 0.75in
line_height: 1
recto_content:
center: '(C) ACME -- v{revnumber}, {docdate}'
verso_content:
center: $header_recto_content
footer:
height: 0.75in
line_height: 1
recto_content:
right: '{section-or-chapter-title} | *{page-number}*'
verso_content:
left: '*{page-number}* | {chapter-title}'You can split the content value across multiple lines using YAML’s multiline string syntax.
In this case, the single quotes around the string are not necessary.
To force a hard line break in the output, add {space}+ to the end of the line in normal AsciiDoc fashion.
footer:
height: 0.75in
line_height: 1.2
recto_content:
right: |
Section Title - Page Number +
{section-or-chapter-title} - {page-number}
verso_content:
left: |
Page Number - Chapter Title +
{page-number} - {chapter-title}|
Tip
|
You can use most AsciiDoc inline formatting in the values of these keys. For instance, to make the text bold, surround it in asterisks (as shown above). One exception to this rule are inline images, which are described in the next section. |
You can add an image to the running header or footer using the AsciiDoc inline image syntax. Note that the image must be the whole value for a given position (left, center or right). It cannot be combined with text.
Here’s an example of how to use an image in the running header (which also applies for the footer).
header:
height: 0.75in
image_vertical_align: 2 # (1)
recto_content:
center: image:footer-logo.png[width=80]
verso_content:
center: $header_recto_content_center-
You can use the
footer_vertical_alignattribute to slighly nudge the image up or down.
|
Caution
|
The image must fit in the allotted space for the running header or footer. Otherwise, you will run into layout issues. Adjust the width attribute accordingly. |
After creating a theme, you’ll need to tell Asciidoctor PDF where to find it. This is done using AsciiDoc attributes.
There are three AsciiDoc attributes that tell Asciidoctor PDF how to locate and apply your theme.
- pdf-stylesdir
-
The directory where the theme file is located. Specifying an absolute path is recommended.
If you use images in your theme, image paths are resolved relative to this directory.
- pdf-style
-
The name of the YAML theme file to load. If the name ends with
.yml, it’s assumed to be the complete name of a file. Otherwise,-theme.ymlis appended to the name to make the file name (i.e.,<name>-theme.yml). - pdf-fontsdir
-
The directory where the fonts used by your theme, if any, are located. Specifying an absolute path is recommended.
Let’s assume that you’ve put your theme files inside a directory named resources with the following layout:
document.adoc
resources/
themes/
basic-theme.yml
fonts/
roboto-normal.ttf
roboto-italic.ttf
roboto-bold.ttf
roboto-bold_italic.ttf
Here’s how you’d load your theme when calling Asciidoctor PDF:
$ asciidoctor-pdf -a pdf-stylesdir=resources/themes -a pdf-style=basic -a pdf-fontsdir=resources/fonts
If all goes well, Asciidoctor PDF should run without an error or warning.
|
Note
|
You only need to specify the pdf-fontsdir if you are using custom fonts in your theme.
|
You can skip setting the pdf-stylesdir attribute and just pass the absolute path of your theme file to the pdf-style attribute.
$ asciidoctor-pdf -a pdf-style=resources/themes/basic-theme.yml -a pdf-fontsdir=resources/fonts
However, in this case, image paths in your theme won’t be resolved properly.
Paths are resolved relative to the current directory. However, in the future, this may change so that paths are resolved relative to the base directory (typically the document’s directory). Therefore, it’s recommend that you specify absolute paths for now to future-proof your configuration.
$ asciidoctor-pdf -a pdf-stylesdir=/path/to/resources/themes -a pdf-style=basic -a pdf-fontsdir=/path/to/resources/fonts