Combine: Asynchronous Programming with Swift

The best book to master declarative asynchronous programming with Swift using the Combine framework!The introduction of Combine into the Swift ecosystem now gives you a native way to manage asynchronous events in Swift, meaning you don’t have to rely on third-party reactive frameworks for event-driven systems.Master declarative asynchronous programming with Swift using the Combine framework!Writing asynchronous code can be challenging, with a variety of possible interfaces to represent, perform, and consume asynchronous work — delegates, notification center, KVO, closures, etc. Juggling all of these different mechanisms can be somewhat overwhelming. Does it really have to be this hard? Not anymore!With Apple’s introduction of the Combine framework in WWDC 2019, it is clear that Apple aims to position declarative and reactive programming in Swift as a long-term investment and a game-changer in how developers perform and compose pieces of asynchronous work, making it a must-have tool at your disposal.The introduction of Combine as a built-in framework in Apple’s ecosystem is promising news to developers who were interested in frameworks such as RxSwift or ReactiveSwift, but didn’t want the overhead of a third-party dependency; and while experience with either of the above could be useful, it is not a prerequisite for this book. You’ll learn everything from the ground up to become a true Combine master. About the Cover About the Authors About the Artist What You Need Book License Book Source Code & Forums Chapter 1: Hello, Combine! Asynchronous programming Foundation of Combine Combine basics What's the benefit of Combine code over "standard" code? App architecture Book projects Key points Where to go from here? Chapter 2: Publishers & Subscribers Getting started Hello Publisher Hello Subscriber Hello Cancellable Understanding what’s going on Creating a custom subscriber Hello Future Hello Subject Dynamically adjusting demand Type erasure Challenge Key points Where to go from here? Chapter 3: Transforming Operators Getting started Collecting values Mapping values Flattening publishers Replacing upstream output Incrementally transforming output Challenge Key points Where to go from here? Chapter 4: Filtering Operators Getting started Filtering basics Compacting and ignoring Finding values Dropping values Limiting values Challenge Key points Where to go from here? Chapter 5: Combining Operators Getting started Prepending Appending Advanced combining Key points Where to go from here? Chapter 6: Time Manipulation Operators Getting started Shifting time Collecting values Collecting values (part 2) Holding off on events Timing out Measuring time Challenge Key points Where to go from here? Chapter 7: Sequence Operators Getting started Finding values Querying the publisher Key points Where to go from here? Chapter 8: In Practice: Project "Collage" Getting started with "Collage" Talking to other view controllers Wrapping a callback function as a future Presenting a view controller as a future Sharing subscriptions Publishing properties with @Published Operators in practice Challenges Key points Where to go from here? Chapter 9: Networking URLSession extensions Codable support Publishing network data to multiple subscribers Key points Where to go from here? Chapter 10: Debugging Printing events Acting on events — performing side effects Using the debugger as a last resort Key points Where to go from here? Chapter 11: Timers Using RunLoop Using the Timer class Using DispatchQueue Key points Where to go from here? Chapter 12: Key-Value Observing Introducing publisher(for:options:) Preparing and subscribing to your own KVO-compliant properties ObservableObject Key points Where to go from here? Chapter 13: Resource Management The share() operator The multicast(_:) operator Future Key points Where to go from here? Chapter 14: In Practice: Project "News" Getting started with the Hacker News API Getting a single story Multiple stories via merging publishers Getting the latest stories Challenges Key points Where to go from here? Chapter 15: In Practice: Combine & SwiftUI Hello, SwiftUI! Getting started with "News" A first taste of managing view state Fetching the latest stories Using ObservableObject for model types Displaying errors Subscribing to an external publisher Initializing the app's settings Editing the keywords list Challenges Key points Where to go from here? Chapter 16: Error Handling Getting started Never Dealing with failure Key points Where to go from here? Chapter 17: Schedulers An introduction to schedulers Operators for scheduling Scheduler implementations Challenges Key points Where to go from here? Chapter 18: Custom Publishers & Handling Backpressure Creating your own publishers Publishers as extension methods The subscription mechanism Publishers emitting values Publishers transforming values Handling backpressure Key points Where to go from here? Chapter 19: Testing Getting started Testing Combine operators Testing production code Challenges Key points Where to go from here? Chapter 20: In Practice: Building a Complete App Getting started Setting goals Implementing JokesViewModel Wiring JokesViewModel up to the UI Implementing Core Data with Combine Challenge Key points Where to go from here? Conclusion