Adding a :redcarpet Haml Filter to Rails

gistfile1.rb

# Thanks to:
# http://stackoverflow.com/questions/1921777/how-to-write-a-haml-custom-filter

# config/initializers/haml_filters.rb
require 'haml/filters/redcarpet'

# lib/haml/filters/redcarpet.rb
require 'redcarpet'

module Haml::Filters::Redcarpet
  include Haml::Filters::Base
  
  def render(text)
    markdown = Redcarpet.new(text)
    return markdown.to_html
  end # method render
end # module Haml::Filters::Redcarpet

A revised version based on this at: https://gist.github.com/peterwake/46b2a2397abff714aea4431491ef9a3e