mimeregistry.rb

module MIMERegistry

  REGISTRY = {}
  EXTENSIONS = {}

  module_function

  # Registers the new MIME-Type and associated extensions.
  # The first one of extensions will be treated as the 'preferred'
  # for the MIME-Type.
  #
  def register(thing, *extensions)
    return if extensions.empty?
    extensions.map! { |ext| ext[0] == ?. ? ext.downcase : ".#{ext.downcase}" }
    extensions.each { |ext| REGISTRY[ext] = thing }
    EXTENSIONS[thing] = extensions.first
    nil
  end

  def lookup(ext, fallback = 'application/octet-stream')
    REGISTRY.fetch(ext[0] == ?. ? ext.downcase : ".#{ext.downcase}", fallback)
  end

  def extension_for(thing, fallback = nil)
    EXTENSIONS.fetch thing, fallback
  end

  # Loads the set of MIME-Types from the Apache compatible mime.types file.
  # original source: webrick.
  def load_from(file)
    open(file) do |io|
      io.each do |line|
        line.strip!
        next if line.empty? || /^#/ === line
        register *line.split(/\s+/)
      end
    end
    true
  end

end

# EOF