Libasciidoc

Libasciidoc is an open source Go library to convert from Asciidoc to HTML.

Supported syntax

Although it does not support the full Asciidoc/Asciidoctor syntax, Libasciidoc already provides users with the following features:

• Title and Sections level 1 to 6

• Document authors and revision

• Attribute declaration and substitution

• Paragraphs and admonition paragraphs

• Delimited Blocks (fenced blocks, listing blocks, example blocks, comment blocks, quoted blocks, sidebar blocks, verse blocks, open blocks)

• Source code highlighting of delimited blocks (use either chroma or pygments as the source-highlighter)

• Literal blocks (paragraph starting with a space, with the .... delimiter or with the [literal] attribute)

• Quoted text (bold, italic, monospace, marked, superscript and subscript) and substitution prevention using the backslash (\) character

• Single and double quoted typographic quotes (e.g. ‘single’ and “double”)

• Explicit and implicit curved apostrophe

• Copyright ©, Registered ®, and Trademark ™ symbols

• Passthrough (wrapping with a single plus or a triple plus, or using the pass:[] or pass:q[] macros)

• External links in paragraphs (https://, http://, ftp://, irc://, mailto:)

• Inline images in paragraphs (image:)

• Image blocks (image::)

• Icons including font, graphic icons, both in admonition blocks and inline (icon:)

• Element attributes (ID, link, title, role, etc.) including short-hand ([#id.role1.role2])

• Ordered lists including custom numbering types (arabic, upperroman, lowergreek, and so forth)

• Unordered lists including bullet styles

• Labeled lists, including [horizontal] and [qanda] styles

• Nesting of links of different types & attributes

• Tables (basic support: header line and cells on multiple lines, top-level table styles)

• Horizontal rules (thematic breaks) and page breaks

• Table of contents

• YAML front-matter

See also the known limitations page for differences between Asciidoc/Asciidoctor and Libasciidoc.

Further elements will be supported in the future. Feel free to open issues here to help prioritizing the upcoming work.

Syntax Highlighting

When enabled, syntax highlighting in [source] blocks is backed by the Chroma libray. The defaut class prefix is tok-, and it can be overridden at the document level using the chroma-class-prefix attribute, or from the command line interface:

:chroma-class-prefix: myprefix- (1)
:chroma-class-prefix: (2)

1. classes with a custom prefix

2. classes without any prefix

$ libasciidoc -o - -a chroma-class-prefix=myprefix- mydoc.adoc

You can also use the chroma CLI (see the release page to download the binary) to generate your CSS with the default prefix or the one of your choice:

$ chroma -s lovelace --html --html-prefix=tok- --html-styles

Output Formats (backend)

Using -b (or --backend) the following formats are supported:

• html5 (also html), this is the default

• xhtml5 (also xhtml)

Installation

To build libasciidoc and make it available on the command line, do this:

$ git clone https://github.com/bytesparadise/libasciidoc.git
$ cd libasciidoc
$ make install

If $GOPATH/bin is already in $PATH, then you should be good. Otherwise, for Linux and macOS users, you can run the following command:

$ sudo ln -s "$PWD/bin/libasciidoc" /usr/local/bin/libasciidoc

Usage

Command Line

The libasciidoc library includes a minimalist command line interface to generate the HTML content from a given file:

$ libasciidoc -s content.adoc

use libasciidoc --help to check all available options.

Code integration

Libasciidoc provides 2 functions to convert an Asciidoc content into HTML:

1. Converting an io.Reader into an HTML document:

   Convert(r io.Reader, output io.Writer, config *configuration.Configuration) (types.Metadata, error)

2. Converting a file (given its name) into an HTML document:

   ConvertFile(output io.Writer, config *configuration.Configuration) (types.Metadata, error)

where the returned types.Metadata object contains the document’s title which is not part of the generated HTML <body> part, as well as the table of contents (even if not rendered) and other attributes of the document.

All options/settings are passed via the config parameter.

Macro definition

The user can define a macro by calling renderer.WithMacroTemplate() and passing return value to conversion functions.

renderer.WithMacroTemplate() defines a macro by the given name and associates the given template. The template is an implementation of renderer.MacroTemplate interface (ex. text.Template)

Libasciidoc calls Execute() method and passes types.UserMacro object to template when rendering.

An example the following:

var tmplStr = `<span>Example: {{.Value}}{{.Attributes.GetAsString "suffix"}}</span>`
var t = template.New("example")
var tmpl = template.Must(t.Parse(tmplStr))

output := &strings.Builder{}
content := strings.NewReader(`example::hello world[suffix=!!!!!]`)
libasciidoc.Convert(content, output, renderer.WithMacroTemplate(tmpl.Name(), tmpl))

How to contribute

Please refer to the Contribute page.

License

Libasciidoc is available under the terms of the Apache License 2.0.

Trademark

AsciiDoc is a trademark of the Eclipse Foundation