Eventception

Eventception is a lightweight and simple Ruby Event System inspired on Symfony Event Dispatcher.

How to Install

Add the following to your Gemfile:

gem 'eventception', '~> 0.1.0'

How to use

You can also read the documentation.

Events

When an event is dispatched, it's identified by a unique name, which any number of listeners might be listening to. An Event instance is also created and passed to all of the listeners. As you'll see later, the Event object itself often contains data about the event being dispatched.

The Dispatcher

The dispatcher is the central object of the event dispatcher system. In general, a single dispatcher is created, which maintains a registry of listeners. When an event is dispatched via the dispatcher, it notifies all listeners registered with that event:

require 'eventception'

dispatcher = Eventception::Dispatcher.new

Adding Listeners

require 'eventception'
class TodoListener
  def on_creation(event)
    puts "created a new to-do with title: '#{event.todo.title}'"
  end
end

listener = TodoListener.new
dispatcher.add_listener(
  event_name: 'todo.created',
  listener: listener,
  listener_method: 'on_creation'
)

Creating and Dispatching an Event

Creating the Event

require 'eventception'
class TodoCreatedEvent < Eventception::Event
    NAME = 'todo.created'.freeze

    attr_reader :todo

    def initialize(todo)
      @todo = todo
    end
end

Dispatching the Event

class Todo
    attr_reader :title

    def initialize(title:)
      @title = title
    end
end

todo = Todo.new('My To-do')
event = TodoCreatedEvent.new(todo)
dispatcher.dispatch(TodoCreatedEvent::NAME, event)

# STDOUT: created a new to-do with title: 'My To-do'

LICENSE

Licensed under GNU LGPLv3

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

Contributors

• Daniel Gomes
• Ivo Anjo