зеркало из https://github.com/github/ruby.git
301 строка
8.4 KiB
Plaintext
301 строка
8.4 KiB
Plaintext
= XMLRPC for Ruby
|
|
|
|
== Author and Copyright
|
|
|
|
Copyright (C) 2001-2004 by Michael Neumann (mailto:mneumann@ntecs.de)
|
|
|
|
Released under the same term of license as Ruby.
|
|
|
|
== Overview
|
|
|
|
XMLRPC is a lightweight protocol that enables remote procedure calls over
|
|
HTTP. It is defined at http://www.xmlrpc.com.
|
|
|
|
XMLRPC allows you to create simple distributed computing solutions that span
|
|
computer languages. Its distinctive feature is its simplicity compared to
|
|
other approaches like SOAP and CORBA.
|
|
|
|
The Ruby standard library package 'xmlrpc' enables you to create a server that
|
|
implements remote procedures and a client that calls them. Very little code
|
|
is required to achieve either of these.
|
|
|
|
== Example
|
|
|
|
Try the following code. It calls a standard demonstration remote procedure.
|
|
|
|
require 'xmlrpc/client'
|
|
require 'pp'
|
|
|
|
server = XMLRPC::Client.new2("http://xmlrpc-c.sourceforge.net/api/sample.php")
|
|
result = server.call("sample.sumAndDifference", 5, 3)
|
|
pp result
|
|
|
|
== Documentation
|
|
|
|
See http://www.ntecs.de/projects/xmlrpc4r. There is plenty of detail there to
|
|
use the client and implement a server.
|
|
|
|
== Features of XMLRPC for Ruby
|
|
|
|
* Extensions
|
|
* Introspection
|
|
* multiCall
|
|
* optionally nil values and integers larger than 32 Bit
|
|
|
|
* Server
|
|
* Standalone XML-RPC server
|
|
* CGI-based (works with FastCGI)
|
|
* Apache mod_ruby server
|
|
* WEBrick servlet
|
|
|
|
* Client
|
|
* synchronous/asynchronous calls
|
|
* Basic HTTP-401 Authentification
|
|
* HTTPS protocol (SSL)
|
|
|
|
* Parsers
|
|
* NQXML (NQXMLStreamParser, NQXMLTreeParser)
|
|
* Expat (XMLStreamParser, XMLTreeParser)
|
|
* REXML (REXMLStreamParser)
|
|
* xml-scan (XMLScanStreamParser)
|
|
* Fastest parser is Expat's XMLStreamParser!
|
|
|
|
* General
|
|
* possible to choose between XMLParser module (Expat wrapper) and REXML/NQXML (pure Ruby) parsers
|
|
* Marshalling Ruby objects to Hashs and reconstruct them later from a Hash
|
|
* SandStorm component architecture Client interface
|
|
|
|
== Howto
|
|
|
|
=== Client
|
|
|
|
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}"
|
|
|
|
=== Client with XML-RPC fault-structure handling
|
|
|
|
There are two possible ways, of handling a fault-structure:
|
|
|
|
==== by catching a XMLRPC::FaultException exception
|
|
|
|
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
|
|
|
|
==== by calling "call2" which returns a boolean
|
|
|
|
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
|
|
|
|
=== Client using Proxy
|
|
|
|
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
|
|
<i>proxy2</i>. 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}"
|
|
|
|
=== CGI-based Server
|
|
|
|
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:
|
|
|
|
==== C/PHP-like (handler functions)
|
|
|
|
require "xmlrpc/server"
|
|
|
|
s = XMLRPC::CGIServer.new
|
|
|
|
s.add_handler("sample.sumAndDifference") do |a,b|
|
|
{ "sum" => a + b, "difference" => a - b }
|
|
end
|
|
|
|
s.serve
|
|
|
|
==== Java-like (handler classes)
|
|
|
|
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")
|
|
|
|
===== Security Note
|
|
|
|
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).
|
|
|
|
==== With interface declarations
|
|
|
|
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
|
|
|
|
=== Standalone server
|
|
|
|
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.
|
|
|
|
=== Choosing a different XML Parser or XML Writer
|
|
|
|
The examples above all use the default parser (which is now since 1.8
|
|
REXMLStreamParser) and a default XML writer. If you want to use a different
|
|
XML parser, then you have to call the <i>set_parser</i> method of
|
|
<tt>XMLRPC::Client</tt> instances or instances of subclasses of
|
|
<tt>XMLRPC::BasicServer</tt> or by editing xmlrpc/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 any
|
|
other parser 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 method <i>set_writer</i>.
|