class Rack::MediaType

# File lib/rack/media_type.rb, line 34
def params(content_type)
  return {} if content_type.nil? || content_type.empty?

  content_type.split(SPLIT_PATTERN)[1..-1].each_with_object({}) do |s, hsh|
    s.strip!
    k, v = s.split('=', 2)
    k.downcase!
    hsh[k] = strip_doublequotes(v)
  end
end

The media type parameters provided in CONTENT_TYPE as a Hash, or an empty Hash if no CONTENT_TYPE or media-type parameters were provided. e.g., when the CONTENT_TYPE is “text/plain;charset=utf-8”, this method responds with the following Hash:

{ 'charset' => 'utf-8' }

This will pass back parameters with empty strings in the hash if they lack a value (e.g., “text/plain;charset=” will return { ‘charset’ => ” }, and “text/plain;charset” will return { ‘charset’ => ” }, similarly to the query params parser (barring the latter case, which returns nil instead)).

# File lib/rack/media_type.rb, line 16
def type(content_type)
  return nil unless content_type && !content_type.empty?
  type = content_type.split(SPLIT_PATTERN, 2).first
  type.rstrip!
  type.downcase!
  type
end

The media type (type/subtype) portion of the CONTENT_TYPE header without any media type parameters. e.g., when CONTENT_TYPE is “text/plain;charset=utf-8”, the media-type is “text/plain”.

For more information on the use of media types in HTTP, see: www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.7