peto

peto is a RPC code generator. Defining types and procedures on RPC from contract files. Contract file is simple YAML format.

name: foo
types:
  human: [name:string, age:integer]
procedures:
  find_human:
    args: [id:integer]
    returns: [found:human]
    errors: [human not found, invalid id]

peto generates some codes.

human.rb(or human.as) : human’s structure class
foo.rb(or foo.as) : procedure class. this has find_human, find_human_response, find_human_error_human_not_found, find_human_error_invalid_id

Use Foo class methods to create hash and send it as JSON string for RPC.

peto has a Rails helper module. Look examples/rails_app and use it, if you want to create Rails RPC server.

Usage

installing:

% gem install peto

contract file (foo.yml):

name: foo

types:
  animal: [name:string]
  user: [name:string, age:integer, animals:array:animal]

procedures:
  set_user:
    args: [user:user]

invoke command:

% peto foo.yml rb -o generated/

use foo.rb:

$: << "generated/"
require "foo"
require "animal"
require "user"

cat = Peto::Animal.new(:name => "cat")
dog = Peto::Animal.new(:name => "dog")
user = Peto::User.new(:name => "alice", :age => 23, :animals=>[cat, dog])

# generating procedure hash
Peto::Foo.set_user(user)

in Rails

setup

create your new application

% rails new myapp

add autoload_paths to config/application.rb

config.autoload_paths += %W(#{config.root}/generated)

add including to app/controller/application_controller.rb

require "peto/rails/rails_controller_helper"

class ApplicationController < ActionController::Base
  include Peto::RailsControllerHelper
  # ...
end

add to test/test_helper.rb

require "peto/rails/rails_controller_test_helper"

class ActionController::TestCase
  include Peto::RailsControllerTestHelper
end

add match to config/routes.rb

match ':controller(/:action)'

using

% # on your rails home
% create contract/foo.yml
% mkdir generated
% peto contract/foo.yml -o generated/

add subaction to app/controller/foo_controller.rb

# this is subaction
def set_user(args)
  respond(123, "foo bar baz")
end

subaction is an action method in imitation of rails controller. this has args to use likes params.

post procedure name and parameters to application, be called subaction. in test/functional/foo_controller_test.rb

test "set_user" do
  peto_post("set_user", Peto::User.new(:name=>"alice"))
  assert_response :success
  assert_peto_response("a"=>123, "b"=>"foo bar baz")
end

run server

% rails server

post next JSON to server/foo/

{
  "procedure" : "set_user",
  "args" : {
    "user" : {
      "name" : "alice"
    }
  }
}

this JSON string is created by

ActiveSupport::JSON.encode(Peto::Foo.set_user(user))

Note on Patches/Pull Requests