SwiftUI Course Overview

Overview

This lecture introduces the Stanford CS193p course on developing iOS applications using SwiftUI, covering course structure, prerequisites, the basics of Xcode, SwiftUI's functional programming model, and an initial project: the "Memorize" card game app.

Course Structure & Prerequisites

• The course teaches iOS app development using SwiftUI, focusing on the system's design.
• Prior experience in coding and familiarity with at least one programming language (ideally more) is required.
• No prior knowledge of functional/reactive programming or UI frameworks is assumed.
• The course emphasizes coding assignments, with no concept quizzes.
• Major prerequisites: CS106A, B, 107/108 or equivalent experience.

Learning Approach

• Combines a narrative approach (building a single large app over several weeks) with "vignette" (topic-focused) learning for balance.
• The main project is a card-matching game ("Memorize"), to be expanded with features like animation and scoring.
• Later in the course, skills will be transferable to Mac, Watch, and TV apps using SwiftUI.

Course Mechanics & Assignments

• Communication via Ed Discussion on Canvas is encouraged.
• Reading assignments (Swift Programming Language reference guide) are given for foundational knowledge—focus on content awareness, not memorization.
• There are six programming assignments and a final project; both must be passed to complete the course.
• Assignment 0 is setup: installing Xcode, connecting GitHub/Apple ID (free accounts).
• Assignments are mostly weekly, with Assignment 3 serving as a "midterm" for independent app development.

Xcode & SwiftUI Basics

• Xcode's main areas: Navigator (left), Editor (center), Inspector (right), Preview/Canvas (right), and Debug/Console (bottom).
• SwiftUI apps are organized into structs that "behave like" views, using : View and required computed property var body: some View.
• Views are composed hierarchically, similar to nesting Lego bricks (analogy).
• Instantiating structs: StructName(arguments); parameter labels like systemName or named specify argument purposes.
• Parameter defaults allow omission of non-essential arguments.
• Modifiers (e.g., .foregroundColor, .padding) adjust views and can be chained or scoped to groups of views.
• Stacks (VStack, HStack, ZStack) arrange views vertically, horizontally, or in depth.

SwiftUI Key Programming Concepts

• struct Name: View { var body: some View { ... } } defines a custom view.
• Views are composed via stacks and modifiers; child views can inherit properties from parent views.
• Conditional logic in view composition is done using if statements inside the view's body.
• New custom views (e.g., CardView) are created to break down complex UI into manageable components.
• Passing data to subviews is done via struct properties with default values as needed.
• SwiftUI uses "View Builders" to convert lists of views into a group (tuple view) for stacks.

Key Terms & Definitions

• SwiftUI — A declarative UI framework for building apps on Apple platforms.
• View — A rectangular screen area that draws content and handles events.
• Struct — A value type in Swift used as the basis for views in SwiftUI.
• Modifier — A function called on a view that returns a modified view.
• Stack — A view that arranges child views vertically (VStack), horizontally (HStack), or in depth (ZStack).
• Computed Property — A property whose value is calculated by code, not stored.
• Protocol — A blueprint for types, e.g., View is a protocol that structs conform to for UI rendering.
• View Builder — A construct to assemble lists of views for layout containers.

Action Items / Next Steps

• Complete Assignment 0: set up Xcode, GitHub, and Apple ID.
• Begin Assignment 1: replicate demonstration code and add enhancements.
• Start reading the Swift programming language reference (follow course reading guide).
• Review course details document on Canvas for logistics and assignment expectations.
• Prepare for next lecture: building game logic and transitioning to grid layouts.