XMLRPC::CGIServer nuby

[Daniel Berger]

Hi all,

I'm familiar with how to setup a standalone XMLRPC server, but I'm
curious about XMLRPC::CGIServer. Is this something that allows you to
slap rpc call results back to a webpage or something? I wasn't clear
from the examples in the documentation. I mean, how do you use this
thing?

I'm a CGI/web noob, in case you couldn't tell. I normally don't deal
with it, but I feel compelled to demonstrate to my coworkers that the
ridiculously bloated J2EE web service I'm working on can be reduced
significantly with Ruby. However, I need a little web interface for
"visual evidence" as it were.

If I'm off base, is there any sort of automated way to create an
XMLRPC server that will autogenerate a simple web page with links to
each handler? Then, each of those links would be a simple form where
I can pass values to the service and get results back in a web page?
Sorta like WebLogic does?

Am I making sense?

Help appreciated. Thanks.

Dan

 

[Kent Sibilev]

I think that XMLRPC:CGIServer is just another way to setup your XMLRPC
Server. Meaning that your XMLRPC requests will go through some CGI
capable web server like Apache, which invokes your XMLRPC:CGIServer.

There are other ways to configure it, for example, as pure ruby
application using XMLRPC::Server or XMLRPC::WEBrickServlet, or as a
mod_ruby application XMLRPC::ModRubyServer.

Cheers,
Kent.

 

[James Britt]

I think that XMLRPC:CGIServer is just another way to setup your XMLRPC
Server. Meaning that your XMLRPC requests will go through some CGI
capable web server like Apache, which invokes your XMLRPC:CGIServer.

This is some untested code assembled from some other code I've used in
Blogtari.

When given an xml-rpc request "someName.someMethod", along with its
arguments, it tries to dynamically load the class SomeName (assumed to
be in a file called SomeName.rb someplace in the 'require' path) and
then invokes someMethod.

So, to implement fooBar.add, with 2 args, you need to provide a class
FooBar with a method add( x, y), and put it in a file called FooBar.rb

(There's also a bit of code that checks to see if tis is running under
mod_ruby.)


One neat trick you can do with this arrangement is write an XML-RPC
method that takes a code string and file name as arguments, and have it
write out a new ruby file on the server. Then you can add new, or
modify existing, XML-RPC functions using XML-RPC.

Some security checks might be a good idea, though.

#!/usr/local/bin/ruby
# File index.rb

require "xmlrpc/server"
# You may also want to munge $: to ensure it
# can find your request handler files.

s = XMLRPC::CGIServer.new

if defined? Apache
s = XMLRPC::ModRubyServer.new
end


def new_from_name( classname, *args)
cname = String.new( classname.untaint )
obj = nil
begin
obj = Object.const_get( cname ).new( *args )
rescue Exception
begin
require cname
obj = Object.const_get( cname ).new( *args )
rescue Exception
raise "Cannot create object #{cname}: #{$!}" unless obj
end
end
obj
end

def call_dynamic( name, *args )
cname, mname = name.split( '.')
begin
handler = new_from_name( class_name_it( cname ) )
return handler.send( mname, *args)
rescue
raise "#{cname}::#{mname} is not implemented: #{$!}"
end
end


s.set_default_handler do |name, *args|
begin
call_dynamic( name, *args )
rescue Exception
raise XMLRPC::FaultException.new(-99, "#{$!}")
end
end

s.serve