hash_extension.rb

# Adapted from the recently uploaded Rails initializer file for
# loading the content of app_config.yml into a variables.sass file.
# 
# Useful for:
#
# Flattening a Hash, i.e.:
# irb> {:foo => :bar, :foobar => {:foo => :bar}}.flatten
#   => {"foobar_foo"=>:bar, "foo"=>:bar}

class Hash
  def flatten(input = nil, prefix = nil)
    input = (input || self)
    output = {}
    input.each do |key,value|
      if value.class == Hash
        output = output.merge(flatten(value, key))
      else
        output["#{prefix ? prefix.to_s+'_' : nil}#{key}"] = value
      end
    end
    return output
  end
end