Make CouchDB accept and store PubSubHubbub feeds! Original concept by @rdfturtle (Tyler Gillies)

So I reckon you have some old and busted RSS or ATOM feeds that you need to pull from whenever you want updates, right?

Well, little buddy, it's time to enter the world of push!

Hook your pull feeds into the magic that is PubSubHubbubb (superfeedr.com does this for you... for free!) and they will push to a specific PubSubHubbubb subscriber endpoint whenever they have new content.

You might be asking "where am I going to get a valid PubSubHubbubb subscriber endpoint to store all of these awesome feed pushes"? Well, i'm glad you asked!

With Couchpubtato, you can make any Couch database act like a valid PubSubHubbubb subscriber endpoint.

Ok, so lets say you want to embed a feed of upcoming calendar events on your sweet blog, but the calendar page only has a junky RSS feed! You can use Superfeedr to push new RSS updates in realtime to a CouchDB of your choice, which turns your previously junky RSS feed into a full JSONP enabled API for maximum client side widget goodness!

Here's an example of this whole thingy working: I log all Portland, OR 911 calls and make them available as ActivityStreams here: http://pdxapi.com/pdx911/feed?descending=true&limit=5

By default this will convert any incoming XML RSS/ATOM feed data into JSON ActivityStreams format. ActivityStreams are the new hotness, pure XML ATOM/RSS is old and busted. Here's an example of an ActivityStreams formatted feed item:

{
   "postedTime":"2010-10-14T00:58:32Z",
   "object": {
       "permalinkUrl": "http://rss.cnn.com/~r/rss/cnn_latest/~3/s52R1lImWu0/index.html",
       "objectType": "article",
       "summary": "O'Donnell, Coons stage feisty debate in Delaware"
   },
   "verb": "post",
   "actor": {
       "permalinkUrl": "http://rss.cnn.com/~r/rss/cnn_latest/~3/s52R1lImWu0/index.html",
       "objectType": "service",
       "displayName": "CNN.com Recently Published/Updated"
   }
}

You can use any CouchDB hosted pubicly (so that Superfeedr can post updates to it), but I'll assume you're working with a free Couch hosted by CouchOne.

Couchpubtato is a CouchApp, which means that you'll have install the CouchApp command line utility to deploy it.

Once you have the couchapp utility working, git clone this repo and go into this folder and execute couchapp init.

You'll have to create a new database to store your data. I'll call mine awesome-events. When you run couchapp push http://your.couchone.com/awesome-events it will enhance your new database with the magical PubSubHubbubb sprinkles contained in Couchpubtato and teach your database how to store PubSubHubbubb data.

Once your database is ready to store data, we need to use Superfeedr to hook up a feed to dump into your new PubSubHubbubb enabled Couch database.

Go get a free Subscriber account at Superfeedr and use the PubSubHubbubb console to make a new PUSH request. Set the Topic to the URL of your RSS or ATOM feed.

For the Callback field, here's what to enter:

http://your.couchone.com/awesome-events/_design/push/_rewrite/xml

When you submit the request on Superfeedr, it should say that everything worked okay.

You can also obviously use the regular PubSubHubbub protocol (that is actually being used by the console) by doing a call like this :

$ curl -X POST http://superfeedr.com/hubbub -u'<superfeedr_user>:<superfeedr_password> -d'hub.mode=subscribe' -d'hub.verify=sync' -d'hub.topic=<feed url> -d'hub.callback=http://your.couchone.com/awesome-events/_design/push/_rewrite/xml' -D-

It should return a 204 if everything was fine, and if not, it will indicate what was wrong in the BODY. There exists PubSubHubbub libraries in many languages.

Now any feed updates will get sent to your Couch and will be converted and saved as JSON ActivityStreams objects.

The MIT License

Copyright (c) 2010 Max Ogden and Tyler Gillies

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

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