I want to make a system for users to specify their own rules for when to receive alerts when something happens in their facebook feed. I want them to be able to say 'please send me an alert when Z happens' and then specify that Z is: 'my friend X posts something that contains Y' or 'my friend X doesnt post anything for two days in a row' or something to that effect.
I want this to be easy for the end-user and allow them to define complex trigger events . Is there a specific method to do that? I know that by modeling the specific entities and their relationships I can probably come up with something. My question is: what domain of computer science is this (some subset of AI?)? Are there generic methods to allow the creation of rules? What can I read before I start?
Thanks