[Rails] Problem with implementing a XML-RPC handler

[woeye at mac.com (Lars Hoss)]

Hi all!

I am currently implementing support for the MovableType API in my Rails 
based weblog engine (known as RubyTwaddle). For now the XML-RPC 
invocations are handled by a special controller:

class XmlrpcController < ApplicationController
   model :weblog

   def initialize
     @server = XMLRPC::BasicServer.new
     @server.add_handler("metaWeblog", MetaWeblogAPI.new)
   end

   def index
     xmlData = @params.to_a[0].to_s
     logger.info("xml-requst: #{xmlData}")
     begin
       xmlResponse = @server.process(xmlData)
     rescue Exception => error
       logger.info("error: #{error}")
     end
     @headers["Content-Type"] = "text/xml"
     logger.info("xml-response: #{xmlResponse}")
     render_text(xmlResponse)
   end
end

Though most of the time this approach works fairly well there's still a 
major problem. In order to get the XML sequence of the XML-RPC 
invocation I convert the params hash into an array, fetch the first 
element and convert it into a string. I have to convert it into an 
array because the the xml sequence of the XML-RPC invocation is the key 
in hash and has no value.
Now the problem is that Rails automatically formats all request 
parameters. For example something like 
"&foo+moo=this+is+a+string+with+spaces" will become @params["foo moo"] 
= "This is a string with spaces". This is of course the correct 
behaviour. In my case, however, this means that all "+" characters in 
the XML sequence gets converted into " " characters. And this affects 
embedded base64 encoded data as well. Therefore it is not possible to 
decode this base64 data back.

I guess that a controller for processing the XML-RPC invocation isn't a 
good approach for a controller seems to be more focused on regular HTTP 
browser requests. What I need is a way to get access to the raw request 
data. Any suggestions? :-)

Regards,
Lars

--
"Stil ist die F?higkeit, komplizierte Dinge einfach zu sagen - nicht 
umgekehrt." -- Cocteau, Jean