Next steps: widgets, watchOS, visionOS and the Swift ecosystem

Add extension targets correctly, share code across Apple platforms, depend on Swift packages safely, and choose where to take the project next.

Extension targets and shared containers

• A widget, watch app or share extension is a separate process with its own binary. It cannot reach the app's in-memory state.
• Share data through an App Group: give both targets the same group identifier and use FileManager.containerURL(forSecurityApplicationGroupIdentifier:).
• Widgets get a strict memory budget and are killed if they exceed it. Return a small, pre-computed snapshot.
• Extension background refreshes are scheduled by the system; treat every refresh as best-effort, never as a timer.

import WidgetKit
import SwiftUI

struct Snapshot: TimelineEntry {
    let date: Date
    let openCount: Int
}

struct Provider: TimelineProvider {
    func placeholder(in context: Context) -> Snapshot {
        Snapshot(date: .now, openCount: 3)
    }

    func getSnapshot(in context: Context, completion: @escaping (Snapshot) -> Void) {
        completion(Snapshot(date: .now, openCount: SharedStore.openCount))
    }

    func getTimeline(in context: Context, completion: @escaping (Timeline<Snapshot>) -> Void) {
        let entry = Snapshot(date: .now, openCount: SharedStore.openCount)
        let next = Calendar.current.date(byAdding: .hour, value: 1, to: .now)!
        completion(Timeline(entries: [entry], policy: .after(next)))
    }
}

Dependencies and cross-platform Swift

// Package.swift for a shared module used by the app and the watch app
// swift-tools-version: 6.0
import PackageDescription

let package = Package(
    name: "Core",
    platforms: [.iOS(.v17), .watchOS(.v10), .macOS(.v14)],
    products: [
        .library(name: "Core", targets: ["Core"])
    ],
    dependencies: [
        .package(url: "https://github.com/apple/swift-log.git", from: "1.6.0")
    ],
    targets: [
        .target(name: "Core", dependencies: [.product(name: "Logging", package: "swift-log")]),
        .testTarget(name: "CoreTests", dependencies: ["Core"])
    ]
)

Pin dependencies with a resolved file committed to the repository and update deliberately. A floating branch dependency turns someone else's force-push into your broken build.

Choosing what to learn next

// A design system is the highest-leverage shared package
public struct PrimaryButton: View {
    public let title: String
    public let action: () -> Void

    public init(title: String, action: @escaping () -> Void) {
        self.title = title
        self.action = action
    }

    public var body: some View {
        Button(title, action: action)
            .buttonStyle(.borderedProminent)
            .controlSize(.large)
    }
}

FAQ

Related

Localization, accessibility and system integration Release engineering: TestFlight, CI and App Store Connect

Last refreshed 2026-09-18.