CODEWITHSUNDEEP
swift
Rob N
Rob N

Reputation: 16399

How to mark Swift declaration as available in iOS and unavailable in macOS

I have a class that only works on iOS 10.0 and up. It's in a Swift package, so Xcode 11 is trying to compile it for macOS too, and complaining. How do I say that it's available on iOS 10.0 only.

These don't work:

@available(iOS 10.0, *)
class Thing { ... }

@available(macOS, unavailable)
@available(iOS 10.0, *)
class Thing { ... }

Some docs: https://docs.swift.org/swift-book/ReferenceManual/Attributes.html

Upvotes: 3

Views: 2375

Answers (2)

Mojtaba Hosseini
Mojtaba Hosseini

Reputation: 119128

Wrap it inside this

#if canImport(UIKit)
    // iOS Only code
#endif

This way it will remove from compiled project if it's not going to iOS device.

You can check with OS type like #if os(iOS) too, but be specific to why you should care about the OS? isn't it because of something especially for iOS like UIKit ? If not, be more general and limit the OS as @Shreeram mentioned.

Upvotes: 4

Shreeram Bhat
Shreeram Bhat

Reputation: 3157

From docs

iOS iOSApplicationExtension macOS macOSApplicationExtension watchOS watchOSApplicationExtension tvOS tvOSApplicationExtension swift You can also use an asterisk (*) to indicate the availability of the declaration on all of the platform names listed above.

So * in @available(iOS 10.0, *) saying that declaration is available in all the other platforms. But we are also specifying that it is not available in macOS. So in the end compiler gets confused and availability wins the war. Instead of using @available you can use compiler flags,

#if os(iOS)
#endif

to specify the compiler to compile code only on iOS.

Upvotes: 7

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