iOS (UIKit)

ios-uikit renders UINavigationController pushes, a UITabBarController, and system text handling, driven from Rust through objc2. The scaffold is a checked-in Xcode project whose build phase calls back into day, so Xcode, day launch and CI all build the same way.

HomeControlsDate & timeStack

Getting started

xcode-select --install          # plus Xcode itself, with an iOS Simulator runtime
cargo install day-cli
day new app my-app --toolkit ios-uikit
cd my-app
day launch -p ios-uikit          # boots a Simulator and installs

day doctor --toolkit uikit verifies Xcode, the Simulator runtimes and the Rust iOS targets. Opening platform/ios/Runner.xcodeproj in Xcode works too; ⌘R builds the same Rust library through the project’s build phase.

day build also generates a local SwiftPM package at build/day/ios/DayPieces (the Swift shims pieces contribute, their SwiftPM dependencies, and the generated SwiftUI embedding glue), which the checked-in Xcode project links. A piece’s platform metadata key raises the deployment floor: day build prints a Raising status and passes IPHONEOS_DEPLOYMENT_TARGET=<floor> to xcodebuild. That setting does not reach ⌘R builds inside Xcode, so for IDE work raise the value in the pbxproj by hand.

Packaging produces a device .ipa:

day pack -p ios-uikit

With signing.ios configured you get a signed App Store export; without it you get an unsigned device build (<stem>-ios-uikit-unsigned.ipa) for sideloading or your own signing. See packaging.

Caveats

• Development is Simulator-first. Device debugging works but gets far less use than the Simulator path.
• Declare permissions before you use them. A gated API without its NS*UsageDescription key terminates the app on first use. Day generates those keys from your [permissions] table, and day lint fails the build when one is missing, so the mistake surfaces in CI.
• day-piece-combobox has no UIKit arm, because iOS has no native combo-box control; it renders as a placeholder. Use picker().menu().
• iOS has no persistent menu bar, so set_app_menu is a no-op; context menus work (UIContextMenuInteraction).
• Window screenshots aren’t implemented in-process; the walkthrough uses simctl io booted screenshot instead.
• Dynamic Type is live: labels set adjustsFontForContentSizeCategory, so text rescales with the user’s system setting and your layout has to tolerate it.

What each piece becomes

The generated coverage matrix, checked in CI, covers every backend; this table adds links and notes.

toggle is the only boolean control, radio behavior is picker().inline(), and list is the only collection; there is no checkbox, stepper, or table piece.

Text measurement is UIKit’s sizeThatFits: on the realized view, so wrapping matches what the system would do anywhere else on the platform.