3: Polymorphic Associations

It's time to talk about polymorphic-associations! Polymorphic associations will allow us to start laying down the ground work to have multiple types of shouts. We'll first focus on refactoring our application to behave in a polymorphic behavior before we add a new type of shout. In order to migrate our old data, we'll need to write a relatively complex migration. We'll also discuss the differences between polymorphic associations and single-table inheritance or STI for short. We'll discuss why using polymorphic behavior was the best decision for our application.