The document discusses real-time web APIs and protocols for pushing data from servers to web clients in real-time, including long-polling, PubSubHubbub, webhooks, websockets, and server-sent events. It also examines services like Pusher and Kaazing that provide these capabilities and promising approaches like using PubSubHubbub, server-sent events, or websockets with additional protocols to indicate media types and enable bi-directional communication.

1. Real-TimeWeb APIs
Ryan J. McDonough
@damnhandy | http://damnhandy.com

2. Options
Protocols
• Long-Polling
• PubSubHubbub
• WebHooks
• WebSockets
• Server-Sent Events
Services
• Pusher
• Kaazing
• PubNub

3. Promising Directions
• PubSubHubbub
• Server-Sent Events (SSE)
• WebSockets + “Something Else”

4. PubSubHubbub

5. WebSockets
• STOMP +WebSockets is an interesting idea
• No ideal way for indicating the sub-protocol used by
theWebSocket
• No way to express what media type is coming over the
wire
• Not sure bi-direction communication is necessary

6. Server-Sent Events
Connection: keep-alive
Content-Type: text/event-stream
Date: Sat, 21 Sep 2013 13:31:59 GMT
data: {"msg": "First message"}nn
event: userlogonn
data: {"username": "John123"}nn
event: updaten
data: {"username": "John123", "emotion": "happy"}nn

7. WhatWould Browser Do?
<script>
var source = new EventSource(’/updates');
source.addEventListener('add',
addHandler,
false);
</script>

8. WhatWould PSHB Do?
Link: <http://example.com/events>;
rel=”hub";

9. Ideas: Links for SSE
Link: <http://example.com/events>; rel="notifications";
type="text/event-stream;data='application/ld+json'";

10. Links forWebSockets +
“Something”
Link: <ws://example.com/events>;
rel=”websocket/something";
type=“application/ld+json";