class BaseWebSocketHandler(tornado.websocket.WebSocketHandler):
def __init__(self, application, request, **kwargs):
tornado.websocket.WebSocketHandler.__init__(self, application, request,
**kwargs)
"""
Instantiate an instance-scoped pubsub to handle websocket
event subscriptions. Allow websocket handlers to treat messages
like events, registering with on:
self.on('frame:update', self._handle_event)
Which would get triggered when an evented 'frame:update'
message comes over the pipe
"""
self.ps = MicroPubSub()
@property
def db(self):
"""A connection to the PostgreSQL database."""
return self.application.db
@property
def pubsub(self):
"""Access to the application-wide pubsub system."""
return self.application.pubsub
def on_message(self, message):
"""
Extract event name and data from message,
call corresponding event handler.
"""
message = json_decode(message)
event = message['name']
data = message['data']
self.ps.publish(event, data=data)
def on(self, event, callback):
"""
Subscribe to some event, presumably coming from the websocket message
"""
self.ps.subscribe(event, callback)
def send(self, event, data=None):
"""
Send an "evented" message out to the websocket client,
i.e. in the form:
{
'name': 'some:event',
'data': {
'some': 'data',
'thinga': 'mabob'
}
}
"""
message = dumps({'name': event, 'data': data})
self.write_message(message)
def __init__(self, application, request, **kwargs):
tornado.websocket.WebSocketHandler.__init__(self, application, request,
**kwargs)
"""
Instantiate an instance-scoped pubsub to handle websocket
event subscriptions. Allow websocket handlers to treat messages
like events, registering with on:
self.on('frame:update', self._handle_event)
Which would get triggered when an evented 'frame:update'
message comes over the pipe
"""
self.ps = MicroPubSub()