Observer Design Pattern in Swift
Behavioral design patterns are an important aspect of software design that provide solutions to problems that arise in software development. One such pattern is the Observer pattern, which is used to define a one-to-many dependency between objects so that when one object changes state, all its dependents are notified and updated automatically.
The Observer pattern falls under the category of Behavioral design patterns and is used to decouple an object’s state from the objects that depend on it. In this article, we will discuss the Observer pattern and demonstrate how it can be implemented in Swift using a code example.
Overview of the Observer Pattern
The Observer pattern consists of two primary components:
- Subject: This is the object that is being observed. It maintains a list of its dependents (observers) and notifies them of any changes in its state.
- Observer: This is the object that is notified of any changes in the state of the subject. It has a method that is called by the subject when its state changes.
When the state of the subject changes, it notifies all its observers by calling their update method. The observers then retrieve the updated state of the subject and update their own state accordingly.
