Combine from A to Z

Combine is a powerful framework in Swift that helps you manage asynchronous data streams, providing a declarative way to handle complex asynchronous operations. It is an integral part of modern iOS development, and can be used in a variety of scenarios, such as network requests, user input, and more.

Here’s an A to Z guide on getting started with Combine in Swift, with code examples for those who have zero experience.

A is for Asynchronous Programming

Asynchronous programming is a programming technique that allows your application to perform multiple tasks concurrently. It is essential for building responsive and efficient iOS applications. Combine is designed to help you work with asynchronous data streams by providing a declarative API.

B is for Bind

The Bind operator is used to bind a value from one publisher to another. The bind operator can be used to update a property on a view whenever the underlying data changes. Here’s an example:

let usernamePublisher = NotificationCenter.default.publisher(for: .UITextFieldTextDidChange)
let passwordPublisher = NotificationCenter.default.publisher(for: .UITextFieldTextDidChange)

let combinedPublisher = Publishers.CombineLatest(usernamePublisher, passwordPublisher)
    .map { (username, password) -> Bool in
        !username.isEmpty && !password.isEmpty
    }

combinedPublisher.assign(to: \.isEnabled, on: loginButton)