Custom Class Event Dispatching in CoffeeScript

Oct 8, 2013 Created

Ever use jQuery and think the .bind() and .trigger() APIs are nice? Here is a small class you can use when writing CoffeeScript to quickly implement the observer pattern in your own objects.

For more involved scenarios, consider using a library like RxJS.

# this: https://gist.github.com/464257 in coffeescript, without the global stuff...
class EventsDispatcher
  callbacks: {}

  bind: (event_name, callback) ->
    @callbacks[event_name] ||= []
    @callbacks[event_name].push callback
    @

  trigger: (event_name, data) ->
    @dispatch event_name, data
    @

  dispatch: (event_name, data) ->
    chain = @callbacks[event_name]
    callback data for callback in chain if chain?

class Connection extends EventsDispatcher
  connect: ->
   @trigger 'connected'


something = new Connection()

something.bind 'connected', ->
  console.log 'i connected!'

something.connect()

View Gist