React.js tutorial in coffeescript. http://facebook.github.io/react/docs/tutorial.html

react-tutorial.coffee

dom = React.DOM


CommentBox = React.createClass
  getInitialState: ->
    {data: []}

  loadCommentsFromServer: ->
    $.ajax
      url: 'comments.json',
      dataType: 'json',
      success: (data) =>
        @setState {data: data}
      error: (xhr, status, err) ->
        console.error 'comments.json', status, err.toString()

  handleCommentSubmit: (comment) ->
    comments = @state.data
    newComments = comments.concat [comment]
    @setState {data: newComments}

    $.ajax
      url: @props.url
      type: 'POST'
      data: comment
      success: (data) =>
        @setState {data: data}

  componentWillMount: ->
    @loadCommentsFromServer()
    setInterval @loadCommentsFromServer, @props.pollInterval

  render: ->
    dom.div {className: 'commentBox'},
      dom.h1(null, 'Comments'),
      CommentList({data: @state.data}),
      CommentForm({onCommentSubmit: @handleCommentSubmit})
      

CommentList = React.createClass
  render: ->
    commentNodes = @props.data.map (comment) ->
      Comment {author: comment.author}, comment.text

    dom.div {className: 'commentList'}
      commentNodes


CommentForm = React.createCLass
  handleSubmit: (ev) ->
    author = @refs.author.getDOMNode().value.trim()
    text = @refs.text.getDOMNode().value.trim()

    @props.onCommentSubmit {author: author, text: text}
    @refs.author.getDOMNode().value = ''
    @refs.text.getDOMNode().value = ''

    preventDefault ev

  render: ->
    dom.form {className: 'commentForm', onSubmit: @handleSubmit}
      dom.input(
        type: 'text'
        placeholder: 'Your name'
        ref: author
      ),
      dom.input(
        type: 'text'
        placeholder: 'Say something fun !'
        ref: text
      ),
      dom.input(
        type: 'submit'
        value: 'Post'
      )



Comment = React.createClass
  render: ->
    converter = new Showdown.converter()
    rawMarkup = converter.makeHtml @props.children.toString()

    dom.div {className: 'comment'},
      dom.h2({className: 'commentAuthor'},
        @props.author
      ),
      dom.span({dangerouslySetInnerHTML: {__html: rawMarkup}})
        

React.renderComponent
  CommentBox({url: 'comments.json', pollInterval: 2000}),
  document.getElementById('content')
  
                  

example.coffee:46:1: error: unexpected indentation
commentNodes
^^^^^^

lol.. Warning don't ever try this at home kids.