graphite

Lightweight event library based on C# Events.

Installation

Add this to your application's shard.yml:

dependencies:
  graphite:
    github: panickbr/graphite

Usage

require "graphite"

• Define a Custom EventArgs

class MyEventArgs < Graphite::EventArgs
  getter string : String
  
  def initialize(@string = "")
  end
end

• Define a Publisher

class Publisher
  getter on_event = Graphite::Event.new(:on_event)

  def event(string)
    on_event.fire MyEventArgs.new(string)
  end
end

:on_event is the Event's signature. It's what a Subscriber will check to react to an Event accordingly

• Define a Subscriber

class Subscriber
  include Graphite::Subscriber # Required

  def on_notify(e : Symbol, args : EventArgs) # Required
    case e
    when :on_event
      # You have to check args type to access its methods/variables
      if args.is_a? MyEventArgs
        call_some_method(args.string) 
      end
    end
  end
end

• Subscribe to an Event

 pub = Publisher.new
 sub = Subscriber.new
 
 pub.on_event << sub

When inside the Subscriber, pass itself to subscribe:

class Subscriber
# ...
  pub.on_event << itself
# ...
end

Done. Now every time Publisher#event or Publisher#on_event.fire is called, all on_event subscribers will be notified and react according to its own #on_notify method.

Development

TODO: Write development instructions here

Contributing

1. Fork it ( https://github.com/[your-github-name]/graphite/fork )
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 a new Pull Request

Contributors

• panickbr panickbr - creator, maintainer