Copyright (C) 2001, 2002 by Michael Neumann (neumann@s-direktnet.de)
Released under the same term of license as Ruby.
You can currently use xmlrpc4r with two parsers, XMLParser and/or NQXML. Both are available at RAA (Ruby Application Archive - <URL:http://www.ruby-lang.org/en/raa.html>).
If you want to use XMLParser (Expat Module for Ruby), you have to install James Clark's XML Parser Toolkit "expat". I recommend using XMLParser, because xmlrpc4r is better tested with it and XMLParser is much faster than NQXML. The advantage of using NQXML is that it is written in pure Ruby.
Then you'll need "xmlrpc4r" of course, which is available at <URL:http://www.fantasy-coders.de/ruby/xmlrpc4r>.
To install xmlrpc4r:
tar -xvzf xmlrpc4r-1_7_12.tar.gz cd xmlrpc4r-1_7_12 su root -c "ruby install.rb"
require "xmlrpc/client" # Make an object to represent the XML-RPC server. server = XMLRPC::Client.new( "xmlrpc-c.sourceforge.net", "/api/sample.php") # Call the remote server and get our result result = server.call("sample.sumAndDifference", 5, 3) sum = result["sum"] difference = result["difference"] puts "Sum: #{sum}, Difference: #{difference}"
There are two possible ways, of handling a fault-structure:
require "xmlrpc/client" # Make an object to represent the XML-RPC server. server = XMLRPC::Client.new( "xmlrpc-c.sourceforge.net", "/api/sample.php") begin # Call the remote server and get our result result = server.call("sample.sumAndDifference", 5, 3) sum = result["sum"] difference = result["difference"] puts "Sum: #{sum}, Difference: #{difference}" rescue XMLRPC::FaultException => e puts "Error: " puts e.faultCode puts e.faultString end
require "xmlrpc/client" # Make an object to represent the XML-RPC server. server = XMLRPC::Client.new( "xmlrpc-c.sourceforge.net", "/api/sample.php") # Call the remote server and get our result ok, result = server.call2("sample.sumAndDifference", 5, 3) if ok sum = result["sum"] difference = result["difference"] puts "Sum: #{sum}, Difference: #{difference}" else puts "Error: " puts result.faultCode puts result.faultString end
You can create a Proxy
object onto which you can call methods. This way it
looks nicer. Both forms, "call" and "call2" are supported through "proxy" and "proxy2".
You can additionally give arguments to the Proxy, which will be given to each XML-RPC
call using that Proxy.
require "xmlrpc/client" # Make an object to represent the XML-RPC server. server = XMLRPC::Client.new( "xmlrpc-c.sourceforge.net", "/api/sample.php") # Create a Proxy object sample = server.proxy("sample") # Call the remote server and get our result result = sample.sumAndDifference(5,3) sum = result["sum"] difference = result["difference"] puts "Sum: #{sum}, Difference: #{difference}"
There are also two ways to define handler, the first is like C/PHP, the second like Java, of course both ways can be mixed:
require "xmlrpc/server" s = XMLRPC::CGIServer.new s.add_handler("sample.sumAndDifference") do |a,b| { "sum" => a + b, "difference" => a - b } end s.serve
require "xmlrpc/server" s = XMLRPC::CGIServer.new class MyHandler def sumAndDifference(a, b) { "sum" => a + b, "difference" => a - b } end end # NOTE: Security Hole (read below)!!! s.add_handler("sample", MyHandler.new) s.serve
To return a fault-structure you have to raise an FaultException e.g.:
raise XMLRPC::FaultException.new(3, "division by Zero")
From Brian Candler:
Above code sample has an extremely nasty security hole, in that you can now call any method of 'MyHandler' remotely, including methods inherited from Object and Kernel! For example, in the client code, you can use puts server.call("sample.send","`","ls") (backtick being the method name for running system processes). Needless to say, 'ls' can be replaced with something else. The version which binds proc objects (or the version presented below in the next section) doesn't have this problem, but people may be tempted to use the second version because it's so nice and 'Rubyesque'. I think it needs a big red disclaimer.
From Michael:
A solution is to undef insecure methods or to use XMLRPC::iPIMethods
as shown below:
class MyHandler def sumAndDifference(a, b) { "sum" => a + b, "difference" => a - b } end end # ... server initialization ... s.add_handler(XMLRPC::iPIMethods("sample"), MyHandler.new) # ...
This adds only public instance methods explicitly declared in class MyHandler (and not those inherited from any other class).
Code sample from the book Ruby Developer's Guide:
require "xmlrpc/server" class Num INTERFACE = XMLRPC::interface("num") { meth 'int add(int, int)', 'Add two numbers', 'add' meth 'int div(int, int)', 'Divide two numbers' } def add(a, b) a + b end def div(a, b) a / b end end s = XMLRPC::CGIServer.new s.add_handler(Num::INTERFACE, Num.new) s.serve
Same as CGI-based server, only that the line
server = XMLRPC::CGIServer.new
must be changed to
server = XMLRPC::Server.new(8080)
if you want a server listening on port 8080. The rest is the same.
The examples above all use the default parser (which is now since 1.6.9 NQXMLParser)
and a default XML writer.
If you want to use XMLParser or XMLStreamParser, then you have to call the #set_parser
method onto XMLRPC::Client
instances or instances of subclasses of XMLRPC::BasicServer
or by editing lib/config.rb.
Client Example:
# ... server = XMLRPC::Client.new( "xmlrpc-c.sourceforge.net", "/api/sample.php") server.set_parser(XMLRPC::XMLParser::XMLParser.new) # ...
Server Example:
# ... s = XMLRPC::CGIServer.new s.set_parser(XMLRPC::XMLParser::XMLStreamParser.new) # ...
or:
# ... server = XMLRPC::Server.new(8080) server.set_parser(XMLRPC::XMLParser::NQXMLParser.new) # ...
Note that XMLStreamParser is incredible faster (and uses less memory) than XMLTreeParser, NQXMLStreamParser or NQXMLTreeParser, and scales well for large documents. For example for a 0.5 MB XML document with many tags, XMLStreamParser is ~350 (!) times faster than NQXMLTreeParser and still ~18 times as fast as XMLTreeParser.
You can change the XML Writer by calling #set_writer
.
Much easier is (when using xmlrpc4r version > 1.6.3) to change the file xmlrpc/config.rb and change there the settings which XML parser/writer to use.
$Id: howto.rd,v 1.18 2003/04/08 15:50:59 mneumann Exp $