Asynchronous Programming with SwiftUI and Combine: Functional Programming to Build UIs on Apple Platforms

Table of Contents
About the Author
Foreword
Preface
Acknowledgments
About This Book
Part: 1
	Chapter 1: SwiftUI: A New Beginning
		Why a New UI Framework?
		SwiftUI Principles
			Declarative vs. Imperative
			State Management
			Composition over Inheritance
			Everything Is a View—Except That It Isn’t
			UIs Are a Function of Their State
		A Quick Tour of SwiftUI
			Prerequisites
			Creating a New SwiftUI App
			Adding Some Interaction to Your App
			Using SwiftUI’s State Management to Keep UI and Model in Sync
		Exercises
		Summary
	Chapter 2: Getting Started with SwiftUI
		What We’re Going to Build
		Composing a View for Displaying a Book
		Build the View with Static Data
		Using the Preview to Make Sure Our View Works As Intended
		Displaying a List of Books
		Setting Up Data Binding
		Adjusting the Preview Canvas
		Making the Code Reusable
			Refactoring the Code Using Extract Subview
			Renaming ContentView
			Keep Complexity in Check
		Views and View Modifiers
		Exercises
		Tips and Tricks
		Summary
	Chapter 3: SwiftUI Building Blocks
		Views
			User Interface Views
				Text Input and Output
				Images
				Controls and Indicators
				Shapes
			Container Views
			Layout Behavior
				Hugging
				Expanding
			Views Are Just Descriptions of the UI
		View Modifiers
			Configuring Views
			Applying View Modifiers to Child Views
			Using View Modifiers to Register Action Handlers
		Summary
	Chapter 4: State Management
		Managing State in SwiftUI
		Binding Value Types
		Binding Objects
		ObservableObject
		@StateObject
			When to Use
		@ObservedObject
			When to Use
		@EnvironmentObject
			When to Use
		Summary
	Chapter 5: Displaying Data in Lists
		Getting Started with Lists in SwiftUI
			Using Other SwiftUI Views Inside List Rows
			Building Custom List Rows
			More Complex List Rows
		Dynamic Lists
			Displaying a List of Elements
			Using List Bindings to Allow Modifying List Items
			Asynchronously Fetching Data
			Pull-to-Refresh
			Searching
		Styling
			List Styles
			Headers and Footers
			List Cells
			Separators
		Actions
			Swipe-to-Delete
			Moving and Deleting Items Using EditMode
			Swipe Actions
				Basic Swipe Actions
				Specifying the Edge
				Swipe Actions and onDelete
				Adding More Swipe Actions
				Full Swipe
				Styling Your Swipe Actions
		Managing Focus in Lists
			How to Manage Focus in SwiftUI
			How to Manage Focus in Lists
			Handling the Enter Key
			What About MVVM?
			Eliminating Empty Elements
		Summary
	Chapter 6: Building Input Forms
		Building Simple Forms
		Showing Data in a Form
		Make It Editable
		Drill-Down Navigation
		Input Validation
			Using .onChange(of:)
			Using a View Model to Handle Form Validation
			Synchronizing a Local Source of Truth with the Global Source of Truth by Using @Binding and @ObservableObject
			Using Combine to Perform Form Validation
		Summary
Part: 2
	Chapter 7: Getting Started with Combine
		What Is Functional Reactive Programming?
		Publishers
		Subscribers
		Operators
		Composing Operators
		Combining Publishers
		Summary
	Chapter 8: Driving UI State with Combine
		Input Validation Using Combine
			The Sign-Up Form View
			The View Model
			Validating the Username
			Displaying Validation Messages
			Encapsulating Combine Pipelines in Computed Properties
			Validating the Password
			Putting It All Together
		Exercises
		Summary
	Chapter 9: Networking with Combine
		Fetching Data Using URLSession
		Using Combine to Fetch Data
			Destructuring Tuples Using Key Paths
			Mapping Data
			Fetching Data Using Combine, Simplified
		Connecting to the UI
		Handling Multithreading
		Optimizing Network Access
			Finding the Root Cause
			Using the share Operator to Share a Publisher
			Using debounce to Further Optimize the UX
			Using removeDuplicates to Avoid Sending the Same Request Twice
		Bringing It All Together
		Exercises
		Summary
	Chapter 10: Error Handling in Combine
		Error Handling Strategies
			Ignoring the Error
			Retrying (with Exponential Backoff)
			Showing an Error Message
			Replacing the Entire View with an Error View
			Showing an Inline Error Message
		Typical Error Conditions and How to Handle Them
			Implementing a Fallible Network API
			Calling the API and Handling Errors
			Handling Device/Network Offline Errors
			Handling Validation Errors
			Handling Response Parsing Errors
			Handling Internal Server Errors
		Summary
	Chapter 11: Implementing Custom Combine Operators
		What Is a Combine Operator?
		Implementing Custom Operators
		Implementing a Retry Operator with a Delay
		Conditionally Retrying
		Implementing a Retry Operator for Exponential Backoff
		Summary
	Chapter 12: Wrapping Existing APIs in Combine
		A Case Study
		Using Combine to Access Firestore
			Using View Models and Published Properties
			Using Combine to Wrap APIs
		Creating Your Own Publishers
			Using PassthroughSubject to Wrap Snapshot Listeners
			Using Future to Implement One-Time Fetching from Firestore
		Summary
	Chapter 13: Combine Schedulers and SwiftUI
		What Is a Scheduler
		Types of Schedulers
		Default Behavior
		Switching Schedulers
			Controlling Upstream Publishers Using subscribe(on:)
			Controlling Downstream Subscribers Using receive(on:)
			Other Operators That Influence Scheduling
		Performing Asynchronous Work
		Integrating with Other APIs
			URLSession
			Firebase
		Summary
Part: 3
	Chapter 14: Getting Started with async/await
		Synchronous Programming with Functions
		Asynchronous Programming with Closures
		Asynchronous Programming with async/await
			Defining and Calling Asynchronous Functions
			Calling Asynchronous Functions in Parallel
		Summary
	Chapter 15: Using async/await in SwiftUI
		Fetching Data Asynchronously Using URLSession
		Calling Asynchronous Code
		The Task View Modifier
		Calling Asynchronous Code When the User Taps a Button
		Using Pull-to-Refresh to Update Views Asynchronously
		Searchable Views and async/await
		Updating the UI from the Main Thread
		Summary
	Chapter 16: Bringing It All Together: SwiftUI, async/await, and Combine
		Fetching Data Using Combine
		Fetching Data Using async/await
		Is This the End of Combine?
		Connecting the UI…
		…to a Combine Pipeline
		…to an async/await Method
		Calling Asynchronous Code from Combine
		Summary
Index