How to check whether a module is available using canImport()
Swift version: 5.4
Writing multi-platform code has its own challenges, but if you use the canImport() compiler test then one big challenge is solved for you: you can write one chunk code to run if a specific module is available, and another chunk otherwise.
For example, this code will check for UIKit, AppKit, and all other possibilities so that you can pick whichever color type is best for the current platform:
#if canImport(UIKit)
// iOS, tvOS, and watchOS – use UIColor
#elseif canImport(AppKit)
// macOS – use NSColor
#else
// all other platforms – use a custom color object
#endifBefore canImport() was available we need to use #if os(macOS) instead, like this:
#if os(iOS) || os(tvOS) || os(watchOS)
// use UIColor
#else
// use NSColor
#endifUsing canImport() is an improvement because it lets you focus on what functionality you want rather than what operating system. So, if UIKit became available on macOS tomorrow you wouldn’t need to change your code to use it.
SPONSORED Join a FREE crash course for iOS devs who want to become complete senior developers — from October 18th to 24th. Learn how to apply iOS app architecture patterns through a series of lectures and practical coding sessions.
Sponsor Hacking with Swift and reach the world's largest Swift community!
Available from iOS 8.0
Similar solutions…
- What is whole module optimization?
- How to use #available to check for API availability
- How to use @available to deprecate old APIs
- How to display different strings based on available space using variantFittingPresentationWidth()
- How to check whether an integer lies inside a range
About the Swift Knowledge Base
This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.
