Change Agent Demo

See the change agent documentation for more details.

Here's an example script to track changes in the White House RSS feed over time. This repository is the resulting data store.

require "change_agent"
require 'open-uri'
require "rss"

# init a change agent data store in the ./data folder
change_agent = ChangeAgent.init "data"

# Set up credentials (only required for private repos or pushing)
change_agent.credentials = Rugged::Credentials::UserPassword.new(
:username => "x-oauth-basic",
:password => ENV["GITHUB_TOKEN"]
)

# fetch the White House blog RSS feed and parse
url = "http://www.whitehouse.gov/feed/blog/white-house"
data = open(url).read
feed = RSS::Parser.parse data

# loop through each post
feed.items.each do |post|

  # do some slight string manipulation on the URL to generate a friendly key
  key = post.link.sub("http://www.whitehouse.gov/blog/", "") + ".html"

  # Set the post content as the value
  value = post.description

  # Save via change agent
  change_agent.set key, value
end

# push changes to GitHub
change_agent.push