== Intro == This package is an early-release of the webhooks / publish-subscribe protocol that http://pubsubhubbub.googlecode.com/ is working and rapidly deploying for various Google services. The protocol itself isn't tied or limited to a Google service; a number of hubs have been created and deployed already (see the above URL for list.) This Haskell package adds support for working with these HTTP-based publish-subscribe hub servers, i.e., you may subscribe to notification to URLs ('topics') from a hub and it will push updates down as they occur (rather than you polling.) == Getting started == The protocol is dependent on having some callback/endpoints to forward 'topic' updates to you locally. There's a number of ways of providing this in Haskell...for testing purposes, I've included a 'fastcgi' proxy/relaying script that handles this; see examples/Main.hs It operates by forwarding incoming requests to a local server for processing -- the thinking being that it provides a robust web front-end, leaving your basic Haskell code to do the interesting bits of proccessing the pubsub notifications. An example of how this could be done is provided in examples/Feeder.hs which uses the pubsubhub service that superfeedr.com provides. To use, you need to: * build the cabal package..(!) * Make the fastcgi script pubsub.fcgi available on 'web-visible' URL. * Adjust the settings at the top of examples/Feeder.hs to match your local settings for the script's URL + settle on a hub to use. For actual code / documentation on the bits that implement the very-straightforward PubSubHub protocol, see Web/PubSub.hs enjoy --sigbjorn 09/08/2009