Barrister for Ruby

This project contains Ruby bindings for the Barrister RPC system.

Installation

Install the package:

gem install barrister

If you are writing a server, you will also need the main barrister command line tool to convert your IDL files to JSON. It's written in Python, and can be installed via:

pip install barrister

See the docs for more information on the barrister tool and IDL format.

Basic Usage

Client

require 'barrister'

# specify URL to the server endpoint
trans = Barrister::HttpTransport.new("http://localhost:7667/calc")

# automatically connects to endpoint and loads IDL JSON contract
# also creates proxy classes on client - one per interface in the IDL
client = Barrister::Client.new(trans)

# make a RPC call
#
# in this example the server exposes a "Calculator" interface 
# that contains a "add" method.
#
puts client.Calculator.add(1, 5.1)

Server

Note, there's no requirement to use Sinatra. Any web framework that provides access to the raw POST data is probably fair game.

Given this IDL:

// file: calc.idl
interface Calculator {
    add(a float, b float) float
    subtract(a float, b float) float
}

That you translate via:

barrister -t "Calculator Service" -j calc.json calc.idl

Then you could write this server:

require 'sinatra'
require 'barrister'

# Define a class that implements the functions in the interface
class Calculator

  def add(a, b)
    return a+b
  end

  def subtract(a, b)
    return a-b
  end

end

# Load the IDL JSON file and create a Server instance
contract = Barrister::contract_from_file("calc.json")
server   = Barrister::Server.new(contract)

# Bind your class to the Calculator interface
# If your IDL has multiple interfaces, you would bind
# them all to the same server instance.
server.add_handler("Calculator", Calculator.new)

# Serve it up
post '/calc' do
  request.body.rewind
  resp = server.handle_json(request.body.read)
  
  status 200
  headers "Content-Type" => "application/json"
  resp
end

Compatibility

Developed on MacOS with Ruby 1.9.3. CI tests run on Linux against Ruby 1.8.7.

Depends on the json gem.

More information

• Annotated source
• Barrister site - Includes examples
• IDL docs - How to write an IDL and convert to JSON

License

Distributed under the MIT license. See LICENSE file for details.

Release / Tag notes

Note to self on how to tag release

# Edit `barrister.gemspec`, bump version and date, then run:

make all
git add -u
git commit -m "bump gem v0.1.0"
git tag -a v0.1.0 -m "version 0.1.0"
git push --tags
make publish