The next stop on our voyage through the Design Patterns galaxy takes us to the Observer design pattern, another of the design patterns found in the GoF catalog. We will find this design pattern useful in situations where one class needs to be kept aware of changes occurring in another class.
The Observer design pattern often is described as a publish and subscribe arrangement between entities. A good example of this is the process of getting a daily newspaper delivered to you. You, as the customer, subscribe to the newspaper. The newspaper publishes a new edition ...
