Usage

The ActivityStream class makes it easy to keep track of things your friends do online, like making blog posts and Twitter updates, etc. It's super simple:

from foaflib.classes.person import Person
from foaflib.utils.activitystream import ActivityStream

# Fetch the FOAF profile of the friend to watch
p = Person("http://www.bill.bloggs.net/foaf.rdf")

# Create an ActivityStream object for that friend
stream = ActivityStream(p)

# Iterate over the latest things they've done:
for event in stream.get_latest_events():
    event_handler(event)

Each value of event in that final loop is an instance of the AcctivityStreamEvent class. This is a very simple class with four attributes:

• type - A string conveying what type of event this is - like "Blog post" or "Twitter", etc.
• detail - A string that explains the gist of the event - like the title of a blog post, or a Twitter status, etc.
• link - A string holding the URL for this event - like the URL of a blog post
• timestamp - A time.struct_time instance representing the time of the event

That's all there is to it!

How does this work?

The ActivityStream object makes use of the weblog property of a FOAF profile to pull in blog posts, and OnlineAccounts specified by the holdsAccount property of a FOAF profile to pull in things like Twitter statuses. If a certain FOAF profile does not have a specified weblog or some OnlineAccounts then an ActivityStream object for that profile will return an empty list of events every time.

Blog posts are pulled in on the basis of the weblog property by using the BeautifulSoup library to parse the HTML of the blog page and look for <link type="rel"/> tags that include the addresses of RSS or Atom feeds. These feeds are then parsed using the feedpraser library.

Everything else is pulled in on the basis of a holdsAccount property using something called a helper. foaflib comes with a number of helpers which use either third party Python libraries (like [code.google.com/p/python-twitter/ Python Twitter]) or foaflib-developed code to create ActivityStreamEvent objects. You can find a complete list of current foaflib helpers at the HelpersList page, and you can find instructions on how to write your own helper for a currently unsupported service at the WritingHelpers page.