EventBus

A simple pubsub event bus for Ruby applications.

Features

Simple, global support for the Observer pattern, aka Publisher-Subscriber.
Publish and subscribe to events throughout your Ruby application.
Listen for events without coupling to the publishing object or class.
Subscribe to events using names or regex patterns.
Works with Rails.

Installation

Install the gem

gem install event_bus

Or add it to your Gemfile and run bundle.

gem 'event_bus'

Usage

Subscribe to an event in your application's initialization code:

EventBus.subscribe('order-placed', StatsRecorder.new, :order_placed)

class StatsRecorder
  def order_placed(details)
    order = details[:order]
    //...
  end
end

Or subscribe a block:

EventBus.subscribe('order-placed') do |details|
  order = details[:order]
  //...
end

Fire the event whenever something significant happens in your application:

class PlaceOrder
  //...
  EventBus.announce('order-placed', :order => current_order, :customer => current_user)
end

See the specs for more detailed usage scenarios.

Compatibility

Tested with Ruby 1.8.7, 1.9.x, JRuby, Rubinius. See the build status for details.

License

(The MIT License)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.