The "Tech. Arch."

From Ruby Silverlight to Ruby Web Service (with a touch of spice)

After validating I could create a C# Silverlight client calling both document-style SOAP .net web service and an RPC-style SOAP Rails web service, it was time to move to the all-in-Ruby scenario.
The advantages such a scenario would bring include:
– increased developer productivity due to single end-to-end language experience
– greater leverage through the expressiveness and power of the Ruby language
– shorter cycle time due lack of compilation step (especially when running on the Silverlight-specific Chiron development web server)
– wider options in terms of class libraries, SDKs, and tools

So let’s look at what is needed to make the Ruby “all-the-way” option work:
1. The ability to leverage traditional .NET assemblies from Ruby.
2. The Silverlight ServiceModel stack (a subset of WCF, right-sized for the client).

IronRuby allows integration with the .NET platform – even using strongly-typed collections! Not bad for a dynamically typed language :-) !!!
The challenge is that the WCF approach requires the use of .NET attributes to “decorate” the contract definition.

[System.ServiceModel.OperationContractAttribute
(AsyncPattern=true, Action="/ws_tst/api/GetTime", ReplyAction="*")]

Unfortunately IronRuby does not support that for the time being (still alpha).
So the solution for now is to:
1. Generate and tweak the web service proxy in C#,
2. Package it up in a small assembly
3. Copy the assembly in the Silverlight .xap package to the Silverlight app folder.
4. Add the assembly declaration to the AppManifest.xaml

[xaml]
[/xaml

Then, we can move on to the Silverlight client implementation:
1. Declare our web service proxy assembly and its namespaces

require "RorMonnetUsaComSoap"
include RorMonnetUsaComSoap
include RorMonnetUsaComSoap::RoRServiceReference

2. Instantiate the WCF client generated for our web service port

@svcproxy = WsTstWsTstPortClient.new()

3. Wire up an event handler for the asynchronous web service call (since Silverlight requires asynchronous calls)

@svcproxy.GetTimeCompleted { |sender, args|  txtResults.text = args.result }

4. Wire up a button event handler to request the asynchronous web service call

btnTest.click { |sender, args| @svcproxy.GetTimeAsync() }

Summary:

require "Silverlight"
require "System"
require "System.ServiceModel"

require "RorMonnetUsaComSoap"

include System
include System::Net
include System::ServiceModel

include RorMonnetUsaComSoap

class App < SilverlightApplication
use_xaml

def initialize

@svcproxy = initializeServiceProxy()

# wire up web service callback
@svcproxy.GetTimeCompleted { |sender, args| handle_get_time_completed(sender, args) }

# wire up the button handler
btnTest.click { |sender, args| handle_btn_clicked(sender, args) }

end #initialize method

def initializeServiceProxy
txtResults.text = "Initializing the svc proxy ..."
proxy = RorMonnetUsaComSoap::RoRServiceReference::WsTstWsTstPortClient.new()
txtResults.text = "proxy initialized! ready!"
return proxy
end

def handle_btn_clicked(sender, args)
txtResults.text = "Ready to invoke the service ..."
@svcproxy.GetTimeAsync();
txtResults.text = "Going ..."
end

def handle_get_time_completed(sender, args)
txtResults.text = "Done! [" + args.result.to_s + "]"
end

end # App class

App.new

Et VoilÃ !