Introduction to SPM artifact bundles

Binary targets and fashionable Swift packages

Swift 5.6 launched numerous new options for the Swift Package deal Supervisor infrastructure. We had been already capable of outline binary targets, and use xcframeworks as binary goal dependencies for our apps. They work nice if you’re focusing on Apple platforms, however sadly the xcframework format will not be suitable with Linux distributions, to not point out the Home windows working system.

That is the place artifact bundles may also help. If you’re creating apps for a number of platforms now you can create an artifact bundle, place all of the suitable variants into this new construction and SPM can select the fitting one primarily based in your structure. 💪

Earlier than we really dive in to our primary matter, I’ll shortly present you the way to create an xcframework and ship it as a binary goal by way of SPM.

XCFrameworks and SPM

Earlier than the introduction of the brand new format we needed to fiddle with FAT binaries to assist a number of platforms. I’ve a deep dive article about frameworks and instruments that you need to use to assemble a FAT binary, however I not advocate it since XCFrameworks are right here to remain. 🔨

As a way to construct an XCFramework, it’s important to use Xcode and a course of may be very easy. You simply have to pick out the Framework kind beneath the iOS tab once you create a brand new venture. Be happy to call it, add your Swift supply code and that is it.

You possibly can construct this venture utilizing the command line for a number of platforms by way of the next script.

# construct for iOS gadgets
xcodebuild archive 
  -scheme MySDK 
  -sdk iphoneos 
  -archivePath "construct/ios_devices.xcarchive" 
  BUILD_LIBRARY_FOR_DISTRIBUTION=YES 
  SKIP_INSTALL=NO
  
# construct for iOS simulators
xcodebuild archive 
  -scheme MySDK 
  -sdk iphonesimulator 
  -archivePath "construct/ios_simulators.xcarchive" 
  BUILD_LIBRARY_FOR_DISTRIBUTION=YES 
  SKIP_INSTALL=NO

# construct for macOS gadgets
xcodebuild archive 
  -sdk macosx MACOSX_DEPLOYMENT_TARGET=11.0 
  -arch x86_64 -arch arm64 
  BUILD_LIBRARY_FOR_DISTRIBUTION=YES 
  -scheme "MySDK" 
  -archivePath "construct/macos_devices.xcarchive" SKIP_INSTALL=NO

# mix the slices and create the xcframework file
xcodebuild -create-xcframework 
  -framework construct/ios_devices.xcarchive/Merchandise/Library/Frameworks/MySDK.framework 
  -framework construct/ios_simulators.xcarchive/Merchandise/Library/Frameworks/MySDK.framework 
  -framework construct/macos_devices.xcarchive/Merchandise/Library/Frameworks/MySDK.framework 
  -output MySDK.xcframework

You possibly can even construct variations for Catalyst and different working programs, if you perform a little search you may simply work out the required parameters and configuration. Lengthy story quick, it is very straightforward to create an xcframework output together with all sort of platform slices for particular gadgets. 😊

Now if you wish to use this XCFramework, you may merely drag and drop it to your Xcode venture and it ought to work with out additional points (if it comprises the mandatory slices). Alternatively you need to use Swift bundle supervisor and create a binary goal an hook up your exterior framework bundle by way of SPM. That is how a quite simple configuration file appears like.

import PackageDescription

let bundle = Package deal(
    title: "MySDK",
    merchandise: [
        .library(name: "MySDK", targets: ["MySDK"]),
    ],
    dependencies: [
        
    ],
    targets: [
        .binaryTarget(name: "MySDK", path: "./MySDK.xcframework")
    ]
)

In your venture you need to use the library product as a regular dependency, and the underlying binary goal will deal with importing the mandatory header information and linking the precise library. The one downside with this method is that it’s macOS (or to be much more exact Apple OS solely).

Say hey to artifact bundles for Swift PM

All proper, so XCFrameworks cannot be used beneath Linux, however folks like to jot down command line scripts in Swift and use them for server aspect initiatives. In some instances these scripts (or plugins), wish to name exterior scripts that aren’t put in on the system by default. That is the place artifact bundles may also help, as a result of it makes potential to ship a number of variations of the identical executable binary file. 🤔

Artifact bundles aren’t a substitute for xcframeworks, however extra like an addition, or enchancment because the proposal title signifies this, for the Swift bundle supervisor plugin structure. They permit us to ship precompiled binary information for a number of platforms, this fashion plugin authors do not should compile these instruments from supply and the plugin execution time might be closely lowered.

There’s a nice weblog submit about wrapping the SwiftLint executable in an artifact bundle, so I do not actually wish to get into the small print this time, as a result of it is fairly simple. The proposal itself helps rather a lot to know the essential setup, additionally the older binary dependencies proposal comprises some associated information good job Swift crew. 👍

I would like to provide an honorable point out to Karim Alweheshy, who’s actively working with the brand new Swift bundle supervisor plugin infrastructure, he has a tremendous repository on GitHub that demos artifact bundles so please have a look in case you have time. 🙏

Anyway, I’ll present you the way to wrap an executable into an artifact bundle. At the moment there is not any solution to wrap libraries into artifact bundles, that is going to be added in a while.

# create a easy hey world executable venture
mkdir MyApp
cd $_
swift bundle init --type=executable

# construct the venture utilizing launch config
swift construct -c launch

# copy the binary
cp $(swift construct --show-bin-path -c launch)/MyApp ./myapp


# init a brand new instance venture
mkdir MyPluginExample
cd $_
swift bundle init 

mkdir myapp.artifactbundle
cd $_
mkdir myapp-1.0.0-macos
cd $_
mkdir bin

Now the file construction is prepared, we must always create a brand new information.json file beneath the artifactbundle listing with the next contents. This may describe your bundle with the out there binary variants, you may check out the proposals for the out there triplets variations.

{
    "schemaVersion": "1.0",
    "artifacts": {
        "myapp": {
            "model": "1.0.0",
            "kind": "executable",
            "variants": [
                {
                    "path": "myapp-1.0.0-macos/bin/myapp",
                    "supportedTriples": ["x86_64-apple-macosx", "arm64-apple-macosx"]
                }
            ]
        }
    }
}

Copy the myapp binary beneath the myapp-1.0.0-macos/bin/myapp location, and at last we’ll make a quite simple command plugin to take advangate of this newly added instrument.

import PackagePlugin
import Basis

@primary
struct MyDistCommandPlugin: CommandPlugin {
    
    func performCommand(context: PluginContext, arguments: [String]) throws {
        let myAppTool = attempt context.instrument(named: "myapp")
        let myAppToolURL = URL(fileURLWithPath: myAppTool.path.string)

        let course of = attempt Course of.run(myAppToolURL, arguments: [])
        course of.waitUntilExit()
    }
}

Watch out with the paths and file names, I used lowercase letters for the whole lot on this instance, I like to recommend to comply with this sample once you create your artifact bundle binaries.

swift bundle plugin --list
# ‘hey’ (plugin ‘HelloCommand’ in bundle ‘MyPluginExample’)
swift bundle hey
# Hiya, world!

That is it, now we have a working artifact bundle with a customized made executable out there for macOS. We are able to use this artifact bundle as a dependency for a plugin and run the instrument through the use of the plugin APIs. I would actually love to have the ability to cross compile Swift libraries and executable information in a while, this might make the event / deployment workflow a bit simpler. Anyway, artifact bundles are a pleasant little addition, I actually like the way in which you may ship binaries for a number of platforms and I hope that we’re going to have the ability to share libraries as properly similarly. 😊