Implementing a Twitter like system for companies notifications.

_tweet.html.mustache

{{#user}}
  <div class="lefted gravatar-box">
    <a href="#tweets/users/{{id}}">
      <img alt="{{full_name}} avatar" src="http://gravatar.com/avatar/{{email_md5}}.png?s=30" title="{{full_name}}">
    </a>
  </div>
{{/user}}
<div class="lefted">
  {{{decorated_status}}}<br/>
  <small><abbr class="timeago" title="{{created_at}}">{{created_at}}</abbr></small>
</div>

_twitter_sidebar.haml

= template_include_tag '/tweets/tweet'
= hidden_field_tag 'current_user_json_info', current_user_json_info
#twitter-sidebar.sidebar
  .right-module.block
    %h3 Team Notifications
    %ul.activity-items
      %li.wat-cf
        = form_tag '', :id => 'tweet-form' do
          = text_field_tag 'new-status', '', :id => 'new-tweet', :placeholder => 'Compose a new notification...'
      %li#waiting-tweets.hidden.wat-cf
    %ul#tweets-list.activity-items

tweet.rb

class Tweet < ActiveRecord::Base
  belongs_to :company
  belongs_to :user

  validates :status, :presence => true

  scope :company, lambda {|company| where(:company_id => company.id) }
  scope :by_date, order('created_at DESC')

  before_save :set_company_id

protected

  def set_company_id
    self.company_id = user.company_id
  end

end

tweet_presenter.rb

class TweetPresenter
  def initialize(tweet)
    @tweet = tweet
  end

  def as_json(*)
    {
      :status => @tweet.status,
      :user_id => @tweet.user_id,
      :created_at => @tweet.created_at && @tweet.created_at.getutc.iso8601,
      :user => {
        :id => @tweet.user.to_param,
        :full_name => @tweet.user.full_name,
        :email_md5 => @tweet.user.email_md5
      }
    }
  end
end

tweet_spec.rb

require 'spec_helper'

describe Tweet do
  subject { Tweet.new }

  describe 'validations' do
    it { should validate_presence_of(:status) }
  end

  describe 'callbacks' do
    it 'stores company_id from the user associated to the tweet' do
      user = Factory.create(:user)
      subject.status = 'This is a tweet'
      subject.user_id = user.id
      subject.save
      subject.company_id.should eql(user.company_id)
    end
  end

end

tweets_controller.rb

class TweetsController < InheritedResources::Base
  actions :index, :create
  respond_to :js

  before_filter :set_default_params, :only => :create

  def index
    index! do |format|
      format.js do
        render :json => 
          collection.reverse.map{|tweet| TweetPresenter.new(tweet)}
      end
    end
  end

  def create
    create! do |format|
      format.js do
        render :json => resource
      end
    end
  end

end

twitter.js.coffee

window.twitter =
  views: {}
  models: {}
  collections: {}



class twitter.Helpers
  @timeago: ->
    $("abbr.timeago").timeago()

  @add_counter_on_title: (cnt) ->
    @strip_counter_on_title()
    document.title = "(#{cnt}) #{document.title}"

  @strip_counter_on_title: ->
    current_title  = document.title
    document.title = current_title.replace(/^\(\d+\)\s/, '')

  @new_tweets_text: (cnt) ->
    if cnt > 1
      "#{cnt} new notifications."
    else
      "#{cnt} new notification."



class twitter.models.Tweet extends Backbone.Model
  status: ->
    @get('status')
  created_at: ->
    @get('created_at') || ISODateString(new Date())
  user: ->
    @get('user')
  decorated_status: ->
    @status().replace /(^|\s)#(\w*[a-zA-Z_]+\w*)/g, (t) ->
      "#{t[0]}<b>#{t.trim()}</b>"



class twitter.collections.Tweets extends Backbone.Collection
  model: twitter.models.Tweet
  url: '/tweets'



class twitter.views.Tweet extends Backbone.View
  tagName: 'li'

  initialize: (options) ->
    super
    # Esta clase no debería ser agregada, pero hay que modificar el CSS
    # para que lo estilos que tiene asociados se apliquen de todos modos.
    @$el.addClass('wat-cf')
    @template = $('#tweets-tweet-template').html()

  render: ->
    @$el.html(Mustache.to_html(@template, @model))
    @



class twitter.views.App extends Backbone.View
  el: '#twitter-sidebar'

  events:
    'submit #tweet-form': 'create_tweet'
    'click #waiting-tweets': 'discover_hidden_tweets'

  initialize: ->
    @input          = @$('#new-tweet')
    @waiting_tweets = @$('#waiting-tweets')
    @tweets_list    = @$('#tweets-list')
    twitter.models.Tweet.defaultUserInfo = JSON.parse($('#current_user_json_info').val())

    @tweets = new twitter.collections.Tweets()
    @tweets.on 'add', @new_tweet, @
    @tweets.on 'reset', @add_all, @
    @tweets.fetch()

  add_one: (tweet, options = {}) ->
    view = new twitter.views.Tweet
      model: tweet
      className: options['className']
    @tweets_list.prepend(view.render().el)
    unless options['batch']
      twitter.Helpers.timeago()

  add_all: ->
    @tweets_list.html('')
    iterator = (tweet) ->
      @add_one(tweet, batch: true)
    @tweets.each iterator, @
    twitter.Helpers.timeago()

  new_tweet: (tweet) ->
    @discover_hidden_tweets()
    @add_one(tweet)
    @input.val('')
    pusher.pushNewTweet(tweet)

  create_tweet: (event) ->
    event.preventDefault()
    event.stopPropagation()
    status = @input.val().trim()
    if status != ''
      new_attributes =
        status: status
        user: twitter.models.Tweet.defaultUserInfo
      @tweets.create new_attributes, {wait: true}

  discover_hidden_tweets: (event) ->
    @tweets_list.find('li.new').removeClass('new')
    @tweets_list.find('li.hidden').removeClass('hidden').addClass('new')
    @waiting_tweets.hide()
    twitter.Helpers.strip_counter_on_title()
    @tweets_list.find('li.new').effect("highlight", {}, 3000);

  receive_tweet_broadcast: (tweet) ->
    @add_one(new twitter.models.Tweet(tweet), {className: 'hidden'})
    @waiting_tweets.show()
    cnt = @tweets_list.find('li.hidden').length
    @waiting_tweets.html(twitter.Helpers.new_tweets_text(cnt))
    twitter.Helpers.add_counter_on_title(cnt)




$ ->
  window.twitterApp = new twitter.views.App()