This is the fourth of an eight part series where Robert is joined by Phil Japikse to discuss design patterns. A design pattern is a best practice you can use in your code to solve a common problem. In this episode, Phil demonstrates the Observer pattern. In this pattern, an object, called the subject, maintains a list of its dependents, called observers, and notifies them automatically of any state changes, usually by calling one of their methods. Phil also compares the Observer pattern to the Publish-Subscribe pattern.

- Sample code: https://github.com/skimedic/presentations