Swift scripts and macOS apps
Swift compiler 101, you may create, construct and run a Swift file utilizing the swiftc command. Think about the simplest Swift program that we are able to all think about in a major.swift file:
print("Hey world!")In Swift if we need to print one thing, we do not even need to import the Basis framework, we are able to merely compile and run this piece of code by operating the next:
swiftc major.swift # compile major.swift
chmod +x major # add the executable permission
./major # run the binary
The excellent news that we are able to take this one step additional by auto-invoking the Swift compiler underneath the hood with a shebang).
#! /usr/bin/swift
print("Hey world!")Now should you merely run the ./major.swift file it’s going to print out the well-known “Hey world!” textual content. 👋
Due to the program-loader mechanism and naturally the Swift interpreter we are able to skip an additional step and run our single-source Swift code as straightforward as an everyday shell script. The excellent news is that we are able to import all kind of system frameworks which are a part of the Swift toolchain. With the assistance of Basis we are able to construct fairly helpful or fully ineffective command line utilities.
#!/usr/bin/env swift
import Basis
import Dispatch
guard CommandLine.arguments.depend == 2 else {
fatalError("Invalid arguments")
}
let urlString = CommandLine.arguments[1]
guard let url = URL(string: urlString) else {
fatalError("Invalid URL")
}
struct Todo: Codable {
let title: String
let accomplished: Bool
}
let activity = URLSession.shared.dataTask(with: url) { information, response, error in
if let error = error {
fatalError("Error: (error.localizedDescription)")
}
guard let response = response as? HTTPURLResponse, response.statusCode == 200 else {
fatalError("Error: invalid HTTP response code")
}
guard let information = information else {
fatalError("Error: lacking response information")
}
do {
let decoder = JSONDecoder()
let todos = strive decoder.decode([Todo].self, from: information)
print("Checklist of todos:")
print(todos.map { " - [" + ($0.completed ? "✅" : "❌") + "] ($0.title)" }.joined(separator: "n"))
exit(0)
}
catch {
fatalError("Error: (error.localizedDescription)")
}
}
activity.resume()
dispatchMain()When you name this instance with a URL that may return an inventory of todos it’s going to print a pleasant record of the gadgets.
./major.swift https://jsonplaceholder.typicode.com/todos
Sure, you may say that this script is totally ineffective, however in my view it is an incredible demo app, because it covers verify command line arguments (CommandLine.arguments), it additionally reveals you wait (dispatchMain) for an async activity, resembling a HTTP name by the community utilizing the URLSession API to complete and exit utilizing the best methodology when one thing fails (fatalError) or should you attain the tip of execution (exit(0)). Only a few strains of code, nevertheless it incorporates a lot information.
Have you ever observed the brand new shebang? In case you have a number of Swift variations put in in your system, you need to use the env shebang to go along with the primary one which’s out there in your PATH.
It is not simply Basis, however you may import AppKit and even SwiftUI. Effectively, not underneath Linux in fact, since these frameworks are solely out there for macOS plus you will have Xcode put in in your system, since some stuff in Swift the toolchain remains to be tied to the IDE, however why? 😢
Anyway, again to the subject, this is the boilerplate code for a macOS software Swift script that may be began from the Terminal with one easy ./major.swift command and nothing extra.
#!/usr/bin/env swift
import AppKit
import SwiftUI
@out there(macOS 10.15, *)
struct HelloView: View {
var physique: some View {
Textual content("Hey world!")
}
}
@out there(macOS 10.15, *)
class WindowDelegate: NSObject, NSWindowDelegate {
func windowWillClose(_ notification: Notification) {
NSApplication.shared.terminate(0)
}
}
@out there(macOS 10.15, *)
class AppDelegate: NSObject, NSApplicationDelegate {
let window = NSWindow()
let windowDelegate = WindowDelegate()
func applicationDidFinishLaunching(_ notification: Notification) {
let appMenu = NSMenuItem()
appMenu.submenu = NSMenu()
appMenu.submenu?.addItem(NSMenuItem(title: "Stop", motion: #selector(NSApplication.terminate(_:)), keyEquivalent: "q"))
let mainMenu = NSMenu(title: "My Swift Script")
mainMenu.addItem(appMenu)
NSApplication.shared.mainMenu = mainMenu
let measurement = CGSize(width: 480, top: 270)
window.setContentSize(measurement)
window.styleMask = [.closable, .miniaturizable, .resizable, .titled]
window.delegate = windowDelegate
window.title = "My Swift Script"
let view = NSHostingView(rootView: HelloView())
view.body = CGRect(origin: .zero, measurement: measurement)
view.autoresizingMask = [.height, .width]
window.contentView!.addSubview(view)
window.heart()
window.makeKeyAndOrderFront(window)
NSApp.setActivationPolicy(.common)
NSApp.activate(ignoringOtherApps: true)
}
}
let app = NSApplication.shared
let delegate = AppDelegate()
app.delegate = delegate
app.run()Particular thanks goes to karwa for the authentic gist. Additionally in case you are into Storyboard-less macOS app improvement, you must positively check out this text by @kicsipixel. These assets helped me loads to place collectively what I wanted. I nonetheless needed to lengthen the gist with a correct menu setup and the activation coverage, however now this model acts like a real-world macOS software that works like a appeal. There is just one subject right here… the script file is getting crowded. 🙈
Swift Bundle Supervisor and macOS apps
So, if we observe the identical logic, meaning we are able to construct an executable bundle that may invoke AppKit associated stuff utilizing the Swift Bundle Supervisor. Straightforward as a pie. 🥧
mkdir MyApp
cd MyApp
swift bundle init --type=executable
Now we are able to separate the parts into standalone information, we are able to additionally take away the provision checking, since we’ll add a platform constraint utilizing our Bundle.swift manifest file. If you do not know a lot about how the Swift Bundle Supervisor works, please learn my SPM tutorial, or in case you are merely curious concerning the construction of a Bundle.swift file, you may learn my article concerning the Swift Bundle manifest file. Let’s begin with the manifest updates.
import PackageDescription
let bundle = Bundle(
identify: "MyApp",
platforms: [
.macOS(.v10_15)
],
dependencies: [
],
targets: [
.target(name: "MyApp", dependencies: []),
.testTarget(identify: "MyAppTests", dependencies: ["MyApp"]),
]
)Now we are able to place the HelloView struct into a brand new HelloView.swift file.
import SwiftUI
struct HelloView: View {
var physique: some View {
Textual content("Hey world!")
}
}The window delegate can have its personal place inside a WindowDelegate.swift file.
import AppKit
class WindowDelegate: NSObject, NSWindowDelegate {
func windowWillClose(_ notification: Notification) {
NSApplication.shared.terminate(0)
}
}We are able to apply the identical factor to the AppDelegate class.
import AppKit
import SwiftUI
class AppDelegate: NSObject, NSApplicationDelegate {
let window = NSWindow()
let windowDelegate = WindowDelegate()
func applicationDidFinishLaunching(_ notification: Notification) {
let appMenu = NSMenuItem()
appMenu.submenu = NSMenu()
appMenu.submenu?.addItem(NSMenuItem(title: "Stop", motion: #selector(NSApplication.terminate(_:)), keyEquivalent: "q"))
let mainMenu = NSMenu(title: "My Swift Script")
mainMenu.addItem(appMenu)
NSApplication.shared.mainMenu = mainMenu
let measurement = CGSize(width: 480, top: 270)
window.setContentSize(measurement)
window.styleMask = [.closable, .miniaturizable, .resizable, .titled]
window.delegate = windowDelegate
window.title = "My Swift Script"
let view = NSHostingView(rootView: HelloView())
view.body = CGRect(origin: .zero, measurement: measurement)
view.autoresizingMask = [.height, .width]
window.contentView!.addSubview(view)
window.heart()
window.makeKeyAndOrderFront(window)
NSApp.setActivationPolicy(.common)
NSApp.activate(ignoringOtherApps: true)
}
}Lastly we are able to replace the principle.swift file and provoke every little thing that must be carried out.
import AppKit
let app = NSApplication.shared
let delegate = AppDelegate()
app.delegate = delegate
app.run()The excellent news is that this method works, so you may develop, construct and run apps domestically, however sadly you may’t submit them to the Mac App Retailer, because the last software bundle will not appear to be an actual macOS bundle. The binary isn’t code signed, plus you will want an actual macOS goal in Xcode to submit the appliance. Then why trouble with this method?
Effectively, simply because it’s enjoyable and I may even keep away from utilizing Xcode with the assistance of SourceKit-LSP and a few Editor configuration. The most effective half is that SourceKit-LSP is now a part of Xcode, so you do not have to put in something particular, simply configure your favourite IDE and begin coding.
You too can bundle assets, since this function is out there from Swift 5.3, and use them by the Bundle.module variable if wanted. I already tried this, works fairly properly, and it’s so a lot enjoyable to develop apps for the mac with out the additional overhead that Xcode comes with. 🥳
