Introduction to SPM artifact bundles

Binary targets and fashionable Swift packages

Swift 5.6 launched numerous new options for the Swift Bundle Supervisor infrastructure. We had been already in a position to outline binary targets, and use xcframeworks as binary goal dependencies for our apps. They work nice in case you are concentrating on Apple platforms, however sadly the xcframework format isn’t appropriate with Linux distributions, to not point out the Home windows working system.

That is the place artifact bundles might help. In case you are creating apps for a number of platforms now you can create an artifact bundle, place all of the appropriate variants into this new construction and SPM can select the suitable one primarily based in your structure. 💪

Earlier than we truly dive in to our predominant matter, I’ll shortly present you the right 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 should use to assemble a FAT binary, however I now not suggest it since XCFrameworks are right here to remain. 🔨

With a purpose to construct an XCFramework, it’s important to use Xcode and a course of could be very easy. You simply have to pick the Framework sort beneath the iOS tab if you create a brand new venture. Be happy to call it, add your Swift supply code and that is it.

You may 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 may even construct variations for Catalyst and different working techniques, if you perform a little search you possibly can simply determine the required parameters and configuration. Lengthy story brief, it’s totally simple to create an xcframework output together with all form of platform slices for particular gadgets. 😊

Now if you wish to use this XCFramework, you possibly can 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 should use Swift package deal 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 seems like.

import PackageDescription

let package deal = Bundle(
    identify: "MySDK",
    merchandise: [
        .library(name: "MySDK", targets: ["MySDK"]),
    ],
    dependencies: [
        
    ],
    targets: [
        .binaryTarget(name: "MySDK", path: "./MySDK.xcframework")
    ]
)

In your venture you should use the library product as a typical dependency, and the underlying binary goal will handle importing the mandatory header information and linking the precise library. The one drawback 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 individuals like to put in writing command line scripts in Swift and use them for server facet tasks. In some circumstances 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 might help, as a result of it makes doable to ship a number of variations of the identical executable binary file. 🤔

Artifact bundles should not a alternative for xcframeworks, however extra like an addition, or enchancment because the proposal title signifies this, for the Swift package deal supervisor plugin structure. They permit us to ship precompiled binary information for a number of platforms, this manner plugin authors do not must compile these instruments from supply and the plugin execution time will 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 main points this time, as a result of it is fairly simple. The proposal itself helps rather a lot to grasp the fundamental setup, additionally the older binary dependencies proposal comprises some associated data good job Swift staff. 👍

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

Anyway, I’ll present you the right way to wrap an executable into an artifact bundle. At present there is not any option 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 package deal 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 package deal 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 data.json file beneath the artifactbundle listing with the next contents. It will describe your bundle with the obtainable binary variants, you possibly can check out the proposals for the obtainable triplets variations.

{
    "schemaVersion": "1.0",
    "artifacts": {
        "myapp": {
            "model": "1.0.0",
            "sort": "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 will make a quite simple command plugin to take advangate of this newly added software.

import PackagePlugin
import Basis

@predominant
struct MyDistCommandPlugin: CommandPlugin {
    
    func performCommand(context: PluginContext, arguments: [String]) throws {
        let myAppTool = attempt context.software(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 every part on this instance, I like to recommend to observe this sample if you create your artifact bundle binaries.

swift package deal plugin --list
# ‘hey’ (plugin ‘HelloCommand’ in package deal ‘MyPluginExample’)
swift package deal hey
# Howdy, world!

That is it, now we have got a working artifact bundle with a customized made executable obtainable for macOS. We are able to use this artifact bundle as a dependency for a plugin and run the software by utilizing 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 possibly can ship binaries for a number of platforms and I hope that we’re going to have the ability to share libraries as nicely in a similar way. 😊