2 questions tagged with "iOS"

The Coordinator pattern is an architectural pattern used in iOS development to manage the flow of navigation within an application. Instead of letting view controllers handle the navigation, a separate coordinator object takes over this responsibility. This leads to a more organized structure where view controllers are only responsible for displaying content, and the coordinator handles the logic of navigating between screens.

Code Examples​

Here's a basic example of implementing the Coordinator pattern in Swift:

protocol Coordinator {
    var childCoordinators: [Coordinator] { get set }
    func start()
}

class MainCoordinator: Coordinator {
    var childCoordinators = [Coordinator]()
    var navigationController: UINavigationController

    init(navigationController: UINavigationController) {
        self.navigationController = navigationController
    }

    func start() {
        let vc = ViewController()
        vc.coordinator = self
        navigationController.pushViewController(vc, animated: true)
    }

    func showDetail() {
        let detailVC = DetailViewController()
        detailVC.coordinator = self
        navigationController.pushViewController(detailVC, animated: true)
    }
}

In this example, MainCoordinator is responsible for initializing the first view controller and handling the navigation logic for showing a detail view controller.

Real-World Applications​

The Coordinator pattern is particularly beneficial in large-scale applications where complex navigation flows exist. By separating the navigation logic from view controllers, the code becomes easier to manage, test, and maintain. It also promotes reusability, as the same coordinator can handle similar navigation flows across different parts of the app.

Common Mistakes​

• Tight Coupling: One common mistake when implementing the Coordinator pattern is allowing coordinators to become tightly coupled with specific view controllers, reducing flexibility.
• Overcomplication: Sometimes, developers overcomplicate the Coordinator pattern by creating too many coordinators for simple flows, leading to unnecessary complexity.

App Transport Security (a.k.a ATS) is Apple’s mechanism to ensure developer’s use HTTPS in their app’s communications.

As I’m sure you know, HTTPS is the secure variation of HTTP. In HTTPS, the same fundamentals of HTTP apply, but with the addition of using TLS (Transport Layer Security) to protect the privacy and integrity of the exchanged data from unauthorized parties and Man in the Middle attacks.

TLS relies on encrypting the communication both ways - from the client to the server and the server to the client. So, with App Transport Security, Apple is ensuring that developers use HTTPS (and as a result TLS) in order to ensure privacy and security for all apps and customers.

You can set NSAllowsArbitraryLoads to true in your application’s .plist which will disable the ATS requirement, but your app will likely be rejected unless you can provide a compelling justification to App Review.