How do I use delegation and data source patterns in Swift?

Delegation and data source patterns are essential design patterns in Swift, widely used in iOS development. They allow for communication between objects and help to manage data flow effectively.

Delegation Pattern

The delegation pattern enables one object to send messages to another object when a specific event happens. This is useful in scenarios like handling user input in a view or responding to network events.

Data Source Pattern

The data source pattern is often used alongside the delegate pattern, primarily in UITableView and UICollectionView data handling. The data source provides the necessary data to fill the table or collection view.

Implementation Example

// Define a protocol for the delegate protocol MyDelegate: AnyObject { func didUpdateData(data: String) } class DataManager { weak var delegate: MyDelegate? func fetchData() { // Simulating a network call or data fetching let data = "Hello, World!" delegate?.didUpdateData(data: data) } } class ViewController: UIViewController, MyDelegate { let dataManager = DataManager() override func viewDidLoad() { super.viewDidLoad() dataManager.delegate = self dataManager.fetchData() } func didUpdateData(data: String) { print(data) // Output: Hello, World! } }

Swift Delegation Pattern Data Source Pattern iOS Development

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