Spine::Hub

Provides Publish/Subscribe pattern.

Installation

To install it, add the gem to your Gemfile:

gem 'spine-hub'

Then run bundle. If you're not using Bundler, just gem install spine-hub.

Usage

class Service
  include Spine::Hub::Publisher

  def action
    publish(:action_executing)
    # ...
    publish(:action_executed, 'OK')
  end
end

class Listener
  include Spine::Hub::Subscriber

  def on_action_executing
    puts 'Executing action'
  end
end

service = Service.new
service.subscribe(Listener.new)
service.on(:action_executed) do |status|
  puts "Action executed: #{ status }"
end
service.action

There is also Spine::Hub::Repeater, which repeats subscribed events. If you need to get more control over subscriber event handling, implement notify method:

class MySubscriber
  def notify(event, *arguments)
    # Handle events
  end
end

When global subscribers are needed, extend your publisher with Spine::Hub::Subcriptions::Global module. It also works with Repeater module.

class Service
  include Spine::Hub::Publisher
  include Spine::Hub::Subscriptions::Global

  def action
    # ...
  end
end

For registering to global scope:

Spine::Hub.subscribe(MySubscriber.new)
Spine::Hub.on(:my_event) do |argument|
  # ...
end