class Connection
  constructor: (@target, @origin, @cb) ->
    $.on window, 'message', @onMessage.bind @

  send: (data) ->
    @target.postMessage "#{g.NAMESPACE}#{JSON.stringify data}", @origin

  onMessage: (e) ->
    return unless e.source is @target and
      e.origin is @origin and
      typeof e.data is 'string' and
      e.data[...g.NAMESPACE.length] is g.NAMESPACE
    data = JSON.parse e.data[g.NAMESPACE.length..]
    for type, value of data
      @cb[type]? value
    return