Newsfeed Module Update

This week, a lot of the work I'm doing is of the fixing/testing/documenting variety.

There are two new features that change the functionality of the newsfeed in notable ways.

One is PubSubHubbub support. It's working, and was surprisingly easy to get running.

It works with a hook in the newsfeed update process. Remember how the feed update process includes a sender (the updated entity) and a list of receivers? Because it's the feed of the receivers thats is being updated, the pubsub ping is made for each of these receivers.

First we get the feed URL for the receiver:

# resolve the URL of the entity's ATOM feed
entity_feed_url = news_feed.getFeedUrl()

Then a POST request is sent to a central hub that includes the feed_url:

headers = {'content-type': 'application/x-www-form-urlencoded'}
post_params = {
'hub.mode': 'publish',
'hub.url': entity_feed_url,
}
payload = urllib.urlencode(post_params)
try:
# can these be sent in a batch?
response = urlfetch.fetch(HUB_URL, method='POST', payload=payload)
except urlfetch.Error:
logging.exception('Failed to deliver publishing message to %s', HUB_URL)

Wow, that was easy, wasn't it?


The second feature is the subscribe-by-star pattern, which already appears in plenty of other Google products and should be useful for people who don't like/understand RSS feeds, since subscribing by the star signs you up for email updates.



Finally, I've posted questions that would be useful to ask Melange users in an optional survey.


The questions are on a survey on my staging server: http://jamstage.appspot.com/survey/take/program/google/gsoc2009/updatepreferences