Graphdown

Markdown extension for embedding graphs.

Installation

$ gem install graphdown

Requirements

• Graphviz

Usage

require "redcarpet"
require "graphdown"

class BaseRenderer < Redcarpet::Render::HTML
  include Graphdown::Renderable
  # include other extensions
end

markdown = Redcarpet::Markdown.new(BaseRenderer, fenced_code_blocks: true)
markdown.render(content)

Example

# Views transition

\```dot
digraph sample {
    A [label = "index.html"];
    B [label = "show.html"];
    C [label = "new.html"];

    A -> B [dir = both];
    A -> C;
    C -> A [label = "redirect"];
}
\```

- Users visit show.html from index.html.
- Users visit index.html from show.html.
- Users visit new.html from index.html.
- Users are redirected to index.html from new.html.

Graphdown parses block codes which language is 'dot' into img tags, which load graph PNG image. The image is generated by Graphviz.