onChange Notify

When people post blog entries these days, they tend to notify a number of public services which keep a list of recently changed blogs. The first was weblogs.com. Then there was blo.gs and a host of other places to ping when one changed an entry.

But what about the service side of things. Perhaps it’s so simple that no one bothered to release code. Or maybe I’m just ignorant.

Anyway, the process is somewhat straightforward, even if the weblogs.com documentation is unnecessarily obtuse.

  1. A change is made to a thing.
  2. The thing making the change notifies another thing.
  3. The thing receiving the notification notes the change.
  4. Other things ask the second thing for a list of things which changed.
  5. Other things ask the first thing for the change.