The document describes a Node Knockout entry called TweetIRC that allows users to follow Twitter sources in a chatroom-like interface. It discusses how TweetIRC was built using Node.js on the backend with a Dojo-based frontend. Key aspects included a plugin framework to handle features and messaging, with the kernel class managing registration and communication between plugins.

1. A Node Knockout entry TweetIRC[.com] London Ajax User Group: JavaScript MiniConf (18 th September 2010)

3. Teams from 1 to 4 members

4. Deployment to Heroku or Joyent, using Git

5. 215 teams around the world

6. My (solo) team was “Celestial Being”, 10 th place “Overall” About nodeko

8. User interface built upon Diijit, inheriting its high-quality widgets browser support and flexibility

9. Will allow the user to “follow” a large number of Twitter “sources” (searches, users, lists, …) in a compact and user friendly interface About TweetIRC

11. Create a solid codebase (don't give in to spaguetti)

12. Maximum browser compatibility

13. Lay groundwork for easy extensibility and modularity

14. Simple straightforward development Project goals

16. Dijit.Layout containers

17. Dojo.publish / dojo.subscribe

18. Dojox.dtl /dojo.cache

19. A core class (“kernel”) to handle features

20. Plugin framework How i built it

22. dijit.layout.TabContainer on the “center” region

23. Chatrooms are a custom TweetIRC.ChatRoom class which extends dijit.layout.BorderContainer

24. London Ajax User Group: JavaScript MiniConf (18 th September 2010) dijit.layout.BorderContainer

25. London Ajax User Group: JavaScript MiniConf (18 th September 2010) The kernel class definition dojo.provide('TweetIRC.Kernel'); dojo.declare("TweetIRC.Kernel", null, { registerPlugin: function(plugin); onTimerTick: function(); onGlobalMessage: function(message); onMessage: function(message); onCommand: function(event); startup: function(/* Object */args); }

26. London Ajax User Group: JavaScript MiniConf (18 th September 2010) The kernel class use dojo.ready(function(){ var kernel = new TweetIRC.Kernel(); // Register plugins kernel.registerPlugin(new TweetIRC.plugins.ChatRoomPlugin()); kernel.registerPlugin(new TweetIRC.plugins.NodeKOPlugin()); kernel.startup(); // Force 1st tick kernel.onTimerTick(); });

27. London Ajax User Group: JavaScript MiniConf (18 th September 2010) Plugins dojo.declare("TweetIRC.BasePlugin", null, { _features: {}, _commands: [], ...

28. London Ajax User Group: JavaScript MiniConf (18 th September 2010) ChatRoomPlugin dojo.declare("TweetIRC.plugins.ChatRoomPlugin", [TweetIRC.BasePlugin], { _chatRooms: [], _selectedChatRoom: null, constructor: function(/* Object */args) { this._features = { 'TweetIRC.features.CommandListener': true, 'TweetIRC.features.GlobalMessageListener': true, 'TweetIRC.features.MessageListener': true, 'TweetIRC.features.DataPoller': true }; this._commands = [ 'JOIN', 'J' ];

29. London Ajax User Group: JavaScript MiniConf (18 th September 2010) Messaging dojo.publish(&quot;/commands&quot;, [{publisher:this, command:'/JOIN #dojo'}]); Pushing messages is easy, from anywhere on the browser onCommand: function(event) { if (event.command.indexOf('/')===0) { <...> for (var i=0; i<this._registeredPlugins.length; i++) { var plugin = this._registeredPlugins[i]; if (plugin.hasFeature('TweetIRC.features.CommandListener') && plugin.hasCommand(command)) { plugin.onCommand(command, args, event); }}} Goes into kernel …

30. London Ajax User Group: JavaScript MiniConf (18 th September 2010) Messaging /** * Handler for /commands */ onCommand: function(command, args, event) { //console.debug(&quot;got command:&quot;+command); //console.debug(args, event); if(command==='JOIN' || command==='J') { this._JOIN(args[0]); } }, … and ends in a plugin

32. Long polling / streaming / Web sockets

33. HTML5 Storage

34. Support for additional networks (Facebook, ...)

35. London Ajax User Group: JavaScript MiniConf (18 th September 2010) The end Q. & A. José Moreira http://zemanel.eu http://twitter.com/zemanel http://pt.linkedin.com/in/josemoreira