Programming

Manging the state of objects and state specific behavior is always an interesting problem to deal with. The Rails community has done a great job of developing libraries to help manage this. Most of these libraries come in the form of State Machines. These typically have the pattern of defining states, events to change states, and constraints by which those states can or cannot change. Usually, this code is maintained in your model, and in some cases states can have their very own model and DB table and keep an audit history of some kind. ...

Polymorphic associations is a common theme among many applications. Things can get complicated, especially as far as naming is concerned, when you consider having a double polymorphic association. Rails provides all the necessary mechanisms by which to manage this in a way that makes sense for most business needs as well as leaving it readable for future programmers that come by in the future. In programming languages and type theory, polymorphism is the provision of a single interface to entities of different types or the use of a single symbol to represent multiple different types. ...