Wiki Formatter for RedClothe Example

wiki-formatter.rb

  #mixin for RedCloth that will convert [[wiki links]] to redcloth links
  module WikiFormatter

    #match  a wiki link (e.g. [[ Foo : Bar ]] or [[foo]])
    # match the sting '[['
    # followed zero or more spaces
    # followed by any amount of text, but as little as possible as Group 1
    # followed zero or more spaces
    # followed (potentially) by a set that is not stored as a match group
    #   which has the charictor ':'
    #   followed zero or more spaces
    #   followed by any amount of text, but as little as possible as Group 2
    #   followed zero or more spaces
    # which is matched zero or one times
    # followed by the string ']]'
    WIKI_MATCH =  /\[\[\s*(.*?)\s*(?:\:\s*(.*?)\s*)?\]\]/

    #When mixed into RedCloth, this method can be used by 
    #passing its name to #to_html.  ex RedCloth.new(str).to_html(:wiki_format)
    def wiki_format(str)
      str.gsub!(WIKI_MATCH) do |s|
        text = $1
        # This calls a function on the model class that normalizes the name so
        # that [[Some Cool Page]] becomes some_cool_page
        uri = Wiki.format_url_title($2 || $1) 
        # $2 allows the link text to differ from the linked page e.g. [[Cool : Some Cool Page]]

        #Change to a textile link.  Could also be an actual <a> tag. 
        %Q<["#{text}":#{Merb::Router.url :wiki_slice_page , :url_title=>uri}]>
      end
    end

  end