module CGI::HtmlExtension

def multipart_form(action = nil, enctype = "multipart/form-data")

#
string

multipart_form("url") { "string" }

#
string

multipart_form{ "string" }

Alternatively, the attributes can be specified as a hash.

type, which defaults to "multipart/form-data".
+action+ is the action to perform. +enctype+ is the encoding

Multipart encoding is used for forms that include file uploads.

Generate a Form element with multipart encoding as a String. 
def multipart_form(action = nil, enctype = "multipart/form-data")
  attributes = if action == nil
                 { "METHOD" => "post", "ENCTYPE" => enctype }
               elsif action.kind_of?(String)
                 { "METHOD" => "post", "ACTION" => action,
                   "ENCTYPE" => enctype }
               else
                 unless action.has_key?("METHOD")
                   action["METHOD"] = "post"
                 end
                 unless action.has_key?("ENCTYPE")
                   action["ENCTYPE"] = enctype
                 end
                 action
               end
  if block_given?
    form(attributes){ yield }
  else
    form(attributes)
  end
end