Project structure and MVVM

Small SwiftUI apps can live in a few files. Real apps need structure so models, views, networking, and business rules do not blend together.

Feature-based organization

Prefer grouping by feature as projects grow:

Features/
  Articles/
    Article.swift
    ArticleService.swift
    ArticleListView.swift
    ArticleDetailView.swift
    ArticleListViewModel.swift
Shared/
  Networking/
  Persistence/
  DesignSystem/

This keeps related files close. A feature can be understood without jumping across many technical folders.

MVVM, practically

MVVM means Model, View, ViewModel.

Model represents app data and rules:

struct Article: Identifiable, Codable {
    let id: String
    let title: String
    let body: String
}

View describes UI:

struct ArticleListView: View {
    @StateObject private var viewModel = ArticleListViewModel()

    var body: some View {
        List(viewModel.articles) { article in
            Text(article.title)
        }
    }
}

ViewModel coordinates loading, user actions, and UI-facing state:

@MainActor
final class ArticleListViewModel: ObservableObject {
    @Published private(set) var articles: [Article] = []

    func refresh() async {
        // Load, validate, and publish state.
    }
}

Keep views honest

Views should not parse JSON, build URLs, decide business rules, or contain large workflows. They should render state and send actions.

Good view code answers: what should appear?

Good view model code answers: what state should the view show next?

Good model code answers: what data is valid?

Swift Package Manager

Swift Package Manager, or SPM, is Swift’s built-in dependency and package tool. In Xcode, you can add packages through package dependencies. In command-line packages, dependencies live in Package.swift.

Use dependencies for clear value: networking helpers, database libraries, image loading, testing tools. Do not add a package for code that is smaller and clearer to write yourself.

What to carry forward

• group larger apps by feature
• models describe valid data
• views render state
• view models coordinate actions and UI-facing state
• keep business logic out of SwiftUI bodies
• SPM manages Swift packages and dependencies

Next, you will test and debug Swift code.