Koine::EventManager

Event manager for ruby.

Installation

Add this line to your application's Gemfile:

gem 'koine-event_manager'

And then execute:

$ bundle

Or install it yourself as:

$ gem install koine-event_manager

Usage

Here follows a simple example

event_manager = Koine::EventManager::EventManager.new

event_manager.listen_to(UserSignedIn) do |event|
  WelcomeEmail.new(event.user).send
end

In your controller, or service:

class UserController < ApplicationController
  def create
    @user = User.create(user_params)

    event_manager.trigger(UserSignedIn.new(@user))

    respond_with(@user)
  end
end

You can also create event listeners:

class UserListener < Koine::EventManager::EventListener
  def initializer
    listen_to(UserSignedIn) do |event|
      WelcomeEmail.new(event.user).send
    end

    listen_to(UserRemovedAccount) do |event|
      PleaseComeBackEmail.new(event.user).send
    end
  end
end

And attach to the event manager:

event_manager = Koine::EventManager::EventManager.new
event_manager.attach_listener(UserListener.new)

# and of course later, you can detach listeners, if you want
event_manager.detach_listener(event_manager.listeners.last)

And trigger the event on the event manager

event_manager.trigger(UserSignedIn.new(some_user))

Subscribers

You can add and remove subscribers as follows:

class MySubscriber
  def publish(event)
    # do something
  end
end

subscriber = MySubscriber.new

event_manager.subscribe(subscriber, to: UserSignedIn)
event_manager.unsubscribe(subscriber, from: UserSignedIn)

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/mjacobus/koine-event-manager. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The gem is available as open source under the terms of the MIT License.