rinterface

Pure Ruby client that can send RPC calls to an Erlang node. It's very much a work in progress.

License: MIT ?

Install

gem install rinterface

Try it out

Open a terminal and run:

rake run

This will start the erlang node named 'math'.

Open another terminal, and run:

ruby examples/client.rb

How to use?

In your Ruby code, make a call to the Erlang node like this:

Erlang::Node(nodename,module,function,args) => [:ok,Response] | [:badprc,Reason]

r = Erlang::Node.rpc("math","math_server","add",[10,20])

if r[0] == :badrpc
  puts "Got and Error. Reason #{r[1]}"
else
  puts "Success: #{r[1]}"
end

Where:

• math is the node name (the -sname of the Erlang node)
• math_server is the name of the module
• add is the funtion to call
• [10,20] is an array of arguments to pass to the function

The result will always be an Array of the form:

[:ok, Response]

Where Response is the result from the Erlang, or:

[:badrpc, Reason]

Where Reason is the 'why' it failed.

Experimental new way

The code above can be written like this now:

Erl::MathServer.add(10, 20)

(Ain`t Ruby a beauty? ;)

So you wanna...

Test your Erlang code from RSpec...

Here's a quick and simple example. Make sure you put the rinterface lib into RAILS_ROOT/lib and start the math_server in 'test'

Call Erlang from your Rails app...

Here's a quick and simple example. Make sure you put the rinterface lib into RAILS_ROOT/lib and start the math_server in 'test' In the controller:

controllers/math_controller.rb

require "lib/rinterface"

class MathController < ApplicationController
  def index
    a = params[:a]
    b = params[:b]
    r = Erlang::Node.rpc("math","math_server","add",[a.to_i,b.to_i])

    if r[0] == :badrpc
      @result = "Error"
    else
      @result = r[1]
    end
  end
end

Finally, add a template for the view, and try 'http://localhost:3000/math?a=2&b=3'. This is not ideal yet and not something I'd use yet in production, but it's a starting point for experimenting.

Specs

Don`t forget to run specs before/after patching.

Use either "rake spec" or "spec spec", it`ll start the erlang daemon automatically.

Other stuff

http://code.google.com/p/a2800276/source/browse/trunk/ruby/erlang/lib

http://code.google.com/p/erlectricity/source/browse/#svn/trunk/lib/erlectricity