Rails ERD が OS X Mavericks でエラーになる問題を改善するRubyコード（prepend を使用しているため Ruby 2.0 以上）

rails_erd_font_fix.rb

require 'rails_erd/diagram/graphviz'

module RailsERD
  class Diagram

    module GraphvizFontFix

      # font name to PostScript name table
      FONTNAMES = {
      	'Arial'        => 'ArialMT',
      	'Arial Bold'   => 'Arial-BoldMT',
      	'Arial Italic' => 'Arial-ItalicMT',
      }

      def entity_options(entity, attributes)
        result = super

        # replace font name
        result[:label].gsub!(/face="([^\"]+)"/) {
          fontname = $1
          psname = FONTNAMES[fontname] || fontname
          %Q|face="#{psname}"|
        }

        result
      end

    end

    class Graphviz

      prepend GraphvizFontFix

      # replace font name
      [GRAPH_ATTRIBUTES, NODE_ATTRIBUTES, EDGE_ATTRIBUTES].each { |attrs|
        fontname = attrs[:fontname]
        attrs[:fontname] = FONTNAMES[fontname] || fontname
      }

    end
  end
end