Setting up a simple Webservice - Why so hard?

rubyonrails-talk
1

Hello everyone.

I want to write a simple webservice in rails, which will accept requests by a javascript client using XML-RPC. Knowing very little about webservices in general, I decided first to set up a couple of simple applications (a server and a client) to learn how webservices work. Using rails 2.0, I first followed the instructions here: http://manuals.rubyonrails.com/read/book/10 and then tweaked my apps to get them working in rails 2.0 as explained here:

Now, please follow me and have a look if I'm doing something wrong, 'cause I cannot get a single thing working...

I set up a single method, which takes a string and returns an integer (it does nothing - it's just to see if it works):

(content of /app/apis/myws_api.rb) class MywsAPI < ActionWebService::API::Base inflect_names false

api_method :givenumber, :expects => [:parameter1=>:string], :returns => [:int]

end

(content of /app/controllers/myws_controller.rb) class MywsController < ApplicationController

    web_service_dispatching_mode :layered     web_service :myws, MywsService.new

end

(content of /app/models/myws_service.rb) class MywsService < ActionWebService::Base web_service_api MywsAPI

    def givenumber(:parameter1)         return 1     end

end

And that should be all, right? Now for the client... I just really wanted just to see something coming out of the webservice in the quickiest and dirtiest way, so I just scaffolded a Thing object. In its edit action, I just call the web service and flash it out:

(excerpt from thing_controller.rb)

def edit

    @myws_client = ActionWebService::Client::XmlRpc.new(MywsAPI, 'http://localhost:3000/myws/api’, :handler_name => 'myws')     flash[:notice] = @myws_client.givenumber('test')     redirect_to(things_path)

end

When I fire things up, something goes wrong. My client gets a most discouraging: "HTTP-Error: 500 Internal Server Error" While mongrel says that there has been a: "LoadError (Expected [my project path]/app/apis/myws_api.rb to define MywsApi)"

Since MywsApi _is_ defined in myws_api.rb, I do not really know what's happening here. I know that the client 'sees' the server, because if I try to call the service with the wrong parameters, example: @myws_client.givenumber('test', 'test2') I get the error: givenumber: wrong number of arguments (2 for 1)

So, where am I messing up? Any help would be much appreciated - Thanks in advance!

Regards, Rey9999

2

That is syntactically incorrect. It should be def givenumber(parameter1). In addition for magic autoload to work, you need to follow the rails naming conventions, so MywsAPI should be MywsApi (see the error message ?)

Fred

3

Thanks for the quick reply!

But now I get another strange error: HTTP-Error: 422 ActionController::InvalidAuthenticityToken (ActionController::InvalidAuthenticityToken)     /vendor/rails/actionpack/lib/action_controller/ request_forgery_protection.rb :79:in `verify_authenticity_token' ...and so on...

Do I need to configure something to let the webservice run?

Thanks

Rey9999

4

Ok, problem solved - I needed to set the options for #protect_from_forgery.

Thanks Fred, now it works like a charm!

Regards,

Rey9999