telegraph.coffee

# A module that allows us to send Backbone events up the tree of components
ReactTelegraph =
  componentWillMount: ->
    # Make BB events available to the component
    _.extend @, Backbone.Events
  
  componentWillUnmount: ->
    # Remove all Backbone event listeners
    @off null, null, null
  
  # Shortcut for triggerWithBubbling
  upstream: (ar...)->
    @triggerWithBubbling(ar...)
    
  triggerWithBubbling: (ar...)->
    # Trigger the event on myself using partial application
    @trigger.bind(@, ar...)()
    
    # And telegraph the event up the component tree
    parent = @props.__owner__
    
    # Only do this if the owner component responds to "triggerWithBubbling"
    # - the extension indicates that the component participates in the 
    # Telegraph system and has the mixin
    if parent and parent.triggerWithBubbling
      parent.triggerWithBubbling(ar...)
    
    # Return self
    @
  
window.ReactTelegraph = ReactTelegraph

MyButton = React.createClass
  mixins: [ReactTelegraph]
  upvoteClicked: ->
    @triggerWithBubbling 'upvote', @props.commentId
    
  render: ->
    (button {onClick: @upvoteClicked}, "Upvote comment #{@props.commentId}!")
  
    
MyComponent = React.createClass
  mixins: [ReactTelegraph]
  
  render: ->
    (div {}, (MyButton {commentId: 123}), (MyButton {commentId: 234}))
  
  componentDidMount: ->
    # Listen to the  "upvote"
    # event via BB events, it's going to be
    # sent from one of the children
    @on 'upvote', (cid) ->
      # Do whatever we have to do
      console.debug "Comment #{cid} upvoted"