How to include the contents of a markdown page into a post with Jekyll?

Question

I am pretty new to websites with Jekyll hosted on Github, and I was wondering if there was a neat way to include the contents of a markdown page (say this one) into a post (say this one) in order to always have the contents up to date if the source page is modified?

Answer 1

Breno Salgado posted this simple Jekyll plugin on StackOverflow:

./_plugins/markdown_tag.rb:

module Jekyll
  class MarkdownTag < Liquid::Tag
    def initialize(tag_name, text, tokens)
      super
      @text = text.strip
    end
    require "kramdown"
    def render(context)
      "#{Kramdown::Document.new(File.read(File.join(Dir.pwd, '_includes', @text))).to_html}"
    end
  end
end
Liquid::Template.register_tag('markdown', Jekyll::MarkdownTag)

According to this page you should be able to use code like this:

{% markdown test.md %}

To render the contents of the markdown file.