Biceps

Easily route your versioned API

Biceps heavily uses the convention over configuration principle. To install it, you just need to add it to your Gemfile.

gem 'biceps'

Once Biceps is installed, you can start adding api-versioned routes. Your config/routes.rb file could look like the following :

MyApp::Application.routes.draw do
  root :to => "home#index"

  api_version(1) do
    get '/me' => "users#show"
  end

  api_version(2) do
    get '/user' => "users#show"
  end
end

This will create two routes :

GET    /me(.:format)                                 {:controller=>"v1/users", :action=>"show"}
GET    /user(.:format)                               {:controller=>"v2/users", :action=>"show"}

As you can see in the routing, both are leading to different namespaces : v1 and v2.
Both namespaces are the version of your API.

You will want to be able to add routing tests to your versionned API. We provide an helper for that.
Include Biceps::TestHelper in your routing specs, and use the mock_api_version method.

Example :

require 'spec_helper'

describe V1::MyApiController do
  include Biceps::TestHelper
  mock_api_version(1)

  it "GET index" do
    get('/my_api').should route_to({:controller => 'v1/my_api', :action => 'index'})
  end
end

You can include this helper in all your routing specs by editing your spec/spec_helper.rb file with the following :

RSpec.configure do |config|
  config.include Biceps::TestHelper,    :type => :routing
end

Internally, biceps is just a rack middleware, which means you can use it with the ruby framework of your choice, including bare rack apps.
We will add a rack env parameter called biceps.versions, which is an array of strings containing all versions specified in the Accept HTTP header.

You can then manage your routing as you wish inside your application.

When you want to call the API, you need to specify the Accept header like this :

application/json,application/vnd.biceps;ver=1

Here is, for example, how you could do it with faraday

connexion = Faraday.new(:url => 'http://api.yourapplication')
connexion.get do |req|
  req.url '/me'
  req.headers['ACCEPT'] = 'application/json, application/vnd.biceps;ver=1'
  req.params['access_token'] = 'xxx'
end

Or, with jQuery, we do it like this :

$.ajaxSetup({
  accepts: {
    biceps: "application/json,application/vnd.biceps;ver=1"
  }
});

$.ajax({
  url: '/me'
  dataType: 'biceps'
}).always(function(response) {
  json = JSON.parse(response.responseText)
});

You can change the app's name used to detect the Accept token easily.

Biceps.app_name = 'example'

We're open to any contribution. It has to be tested properly though.

• Fork the project
• Do your changes and commit them to your repository
• Test your changes. We won't accept any untested contributions (except if they're not testable).
• Create an issue with a link to your commits.

• Damien MATHIEU (github/dmathieu, dmathieu.com)
• Franck VERROT (github.com/franckverrot,franck.verrot.fr)

MIT License. Copyright 2011 Evome. http://evome.fr