Designing Apps with Swift: Using the Mediator Pattern
As mobile app developers, we know that designing an application’s architecture is a very important task. We must ensure that the app performs well and that it is maintainable and extensible. One of the most popular design patterns for this purpose is the Mediator pattern. In this article, we’ll explore how to use the Mediator pattern to design an iOS application with Swift.
The Mediator pattern is a behavioral design pattern which is used to reduce the complexity of an application by decoupling its components. It defines a “mediator” object which acts as a central hub for communication between the components. The components send messages to the mediator object, and the mediator object then forwards the message to the appropriate component.
This pattern can be particularly useful when developing mobile applications. Mobile apps often have a large number of components, and the Mediator pattern can help reduce the complexity of managing them. It also helps to keep the code clean and organized.
Let’s take a look at an example of how to use the Mediator pattern in a Swift application. We’ll use the basic structure of the MVC (Model-View-Controller) pattern as our starting point. We’ll create a view controller which will act as the mediator object. It will handle communication between the model and the view.
First, let’s define the model object. This could be a simple data object, such as a user profile or a list of items. For this example, we’ll use a simple User object:
struct User {
let name: String
let age: Int
}
Next, we’ll define our view controller. This will act as the mediator object and will handle communication between the model and the view. It will have two properties, one for the model object and one for the view object:
class ViewController: UIViewController {
var model: User?
var view: UIView?
//...
}
Now, we’ll add a method to the view controller which will be used to update the view. This method will take a User object and update the view based on its properties:
func updateView(with user: User) {
// Update the view based on the user's properties
view?.backgroundColor = user.age > 18 ? .green : .red
}
Finally, we need to add a method which will be used to update the model object. This method will take a User object and update the model based on its properties:
func updateModel(with user: User) {
// Update the model based on the user's properties
model = user
}
Now that we’ve defined our model, view, and mediator object, we can use them to build our application. We can use the updateView() and updateModel() methods to communicate between the model and the view. For example, if we receive an updated User object from a web service, we can pass it to the view controller, which will then update the model and the view accordingly.
Using the Mediator pattern is a great way to design an iOS application with Swift. It helps to reduce the complexity of the application by decoupling its components and providing a single point of contact for communication. Furthermore, it keeps the code organized and maintainable. If you’re looking for a way to make your application more scalable and extensible, the Mediator pattern is a great option.