Swift helps in implementing the decorator pattern by providing closures (also known as object decorators), and class extensions (also known as Swift extensions). Closures allow us to create decorator functions that can be passed into other functions or classes. This makes it easy to add new functionality to a class without having to subclass it.
For example, we could use a closure to decorate the `drive()` method of our `Car` class. We could add a decorator function that logs the time and date when the car is driven. This would be useful for tracking when the car is driven and how far it’s driven.We could also use closures to decorate the `price` property of our `Car` class. We could add a decorator function that calculates the price of gas for us. This would be useful for calculating the total cost.
Another way Swift helps in implementing the decorator pattern is by providing class extensions. Class extensions allow us to add new methods and properties to an existing class. This is useful for adding new functionality to a class without having to subclass it.For example, we could use a class extension to add the `calculateGasPrice()` method to our `Car` class. This would be useful for calculating the price of gas for us.
Overall, Swift makes it easy to implement the decorator pattern. Using closures and class extensions, we can easily add new functionality to a class without having to subclass it. This makes the decorator pattern a powerful tool for creating flexible and extensible code.
Nyisztor, K. (2019, April 5th). The Decorator Pattern. From the LinkedIn Learning course Pratical Design Patterns in Swift. Retrieved from URL https://www.linkedin.com/learning/practical-design-patterns-in-swift/enhancing-a-type-without-modifying-it