djangocon europe 2012 - sync-models
TRANSCRIPT
Sync-ModelsSynchronizing Object Graphs in Realtime
Wednesday, 6. June 2012 [W]
Basic idea
Synchronize object graphs
Push changes via long-polling(future plan: WebSockets, SSE)
Every object gets an unique idto identify the object
Once part of the graph - push updates to the client automatically
Server
Client
Push!!!11one
Wednesday, 6. June 2012 [W]
Ingredients
Django (only some nifty bits of it)
gevent
“Simple JavaScript Inheritance” by John Resig
KnockoutJS
kodex.sync (to be released under F/OSS license) Help wanted. Meet me
at the sprint on thursday.
Wednesday, 6. June 2012 [W]
Architecture
Server
Client
Long pollingCall WebSocketSSE*
*Server-sent eventsWednesday, 6. June 2012 [W]
Server side
from kodex.sync import models
class BulletinBoard(models.RootModel): messages = models.ReferenceListField()
class Message(models.Model): user = models.ReferenceField() text = models.StringField()
Wednesday, 6. June 2012 [W]
Server side
from kodex.sync import server
class Server(server.SyncServer):
def __init__(self): self.root = BulletinBoard()
def post(message): self.root.messages.append(message)
Wednesday, 6. June 2012 [W]
Client side<div id=”bb”> <ul class=”messages” data-bind=” foreach: root.messages”> <li> <span class=”user” data-bind=” text: user”></span>: <span class=”text” data-bind=” text: user”></span> </li> </ul></div>
Wednesday, 6. June 2012 [W]
Client side
bb.Client = kodex.sync.Client.extend({ post: function(text) { this.request(‘post’, { text: text }) }})
var client = new bb.Client();$(‘#bb’).koApplyBindings(client);
Wednesday, 6. June 2012 [W]
Live Demo
Wednesday, 6. June 2012 [W]
Protocol(Snapshot)
{ “0”: { “class”: “bb.BulletinBoard”, “messages*”: [1] }, “1”: { “class”: “bb.Message”, “user*”: 2, “text”: “What rocks?” }, “2”: { “class”: “auth.User”, “username”: “bikeshedder” }}
Wednesday, 6. June 2012 [W]
Protocol(Updates)
{ “0”: { “messages*”: [2, 4] }, “4”: { “class”: “bb.Message”, “user*”: 5, “text”: “Django and DjangoCon Europe 2012” }, “5”: { “class”: “auth.User”, “username”: “solid” }}
Wednesday, 6. June 2012 [W]
Protocol(Delete)
{ “0”: { “messages*”: [4] }, “1”: null, “2”: null}
Not implemented, yet.
Wednesday, 6. June 2012 [W]
http://bikeshedder.com/
KODEX beta sign-up:http://kodexgame.com/beta/
Wednesday, 6. June 2012 [W]