[macosx][ios][swift3]build and run minimal ios app for simulator with command line only (Xcode-8.1 env, without Storyboard and InterfaceBuilder)

Info.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	<key>CFBundleDevelopmentRegion</key>
	<string>en</string>
	<key>CFBundleExecutable</key>
	<string>webkit</string>
	<key>CFBundleIdentifier</key>
	<string>bellbind.example.webkit</string>
	<key>CFBundleInfoDictionaryVersion</key>
	<string>6.0</string>
	<key>CFBundleName</key>
	<string>webkitexample</string>
	<key>CFBundlePackageType</key>
	<string>APPL</string>
	<key>CFBundleShortVersionString</key>
	<string>1.0</string>
	<key>CFBundleVersion</key>
	<string>1</string>
	<key>LSRequiresIPhoneOS</key>
	<true/>
	<key>UIRequiresFullScreen</key>
	<true/>
	<key>UISupportedInterfaceOrientations</key>
	<array>
		<string>UIInterfaceOrientationPortrait</string>
		<string>UIInterfaceOrientationLandscapeLeft</string>
		<string>UIInterfaceOrientationLandscapeRight</string>
	</array>
</dict>
</plist>

Makefile

phone:="iPhone 7"
#phone:="iPhone 7 Plus"
udid:=$(shell xcrun simctl list|ruby -ne 'exit(print($$1).to_i) if /^    '$(phone)' \(([\-a-fA-F0-9]+)\)/')

#bin:=webkit
bin:=$(shell xmllint --xpath '//key[text()="CFBundleExecutable"]/following::string[1]/text()' Info.plist)
src:=$(bin).swift
appdir:=webkit.app/
#appid:=bellbind.example.webkit
appid:=$(shell xmllint --xpath '//key[text()="CFBundleIdentifier"]/following::string[1]/text()' Info.plist)

echo:
	echo "$(phone)"
	echo "$(udid)"

simapp:
	xcrun -sdk iphonesimulator swiftc -target x86_64-apple-ios10.2 $(src)
	mkdir -p $(appdir)
	cp Info.plist $(bin) $(appdir)

phoneapp:
	xcrun -sdk iphoneos swiftc -target arm64-apple-ios10.2 $(src)
	mkdir -p $(appdir)
	cp Info.plist $(bin) $(appdir)

open:
	open -a Simulator --args -CurrentDeviceUDID $(udid)

# install and uninstall app to the booted simulator (require to open)
install:
	xcrun simctl install $(udid) $(appdir)

uninstall:
	xcrun simctl uninstall $(udid) $(appid)

showlog:
	tail -f ~/Library/Logs/CoreSimulator/$(udid)/system.log

webkit.swift

//[build for simulator]
// xcrun -sdk iphonesimulator swiftc -target x86_64-apple-ios10.1 webkit.swift
//[build for iphoneos]
// xcrun -sdk iphoneos swiftc -target arm64-apple-ios10.1 webkit.swift

//[app file layout - copy as them]
// - ./webkit.app/webkit
// - ./webkit.app/Info.plist

//[simulator]
// xcrun simctl list # print "Devices" as:
//    # iPhone 7 (692EF6C3-3ED6-4782-AF31-01376D781311) (Shutdown)
//[boot with GUI]
// open -a Simulator \
//    --args -CurrentDeviceUDID 692EF6C3-3ED6-4782-AF31-01376D781311
//[shutdown]
// xcrun simctl shutdown 692EF6C3-3ED6-4782-AF31-01376D781311

//[install app (with directory name)]
// xcrun simctl install 692EF6C3-3ED6-4782-AF31-01376D781311 ./webkit.app
//[uninstall app (with CFBundleIdentifier)]
// xcrun simctl install 692EF6C3-3ED6-4782-AF31-01376D781311 \
//    bellbind.example.webkit

// [file path of the simulator log]
// ~/Library/Logs/CoreSimulator/692EF6C3-3ED6-4782-AF31-01376D781311/system.log
import UIKit

class AppDelegate: UIResponder, UIApplicationDelegate {
    var window: UIWindow?
    func application(
      _ application: UIApplication,
      didFinishLaunchingWithOptions launchingOptions:
        [UIApplicationLaunchOptionsKey : Any]? = nil) -> Bool {
        let frame = UIScreen.main.bounds
        let win = UIWindow(frame: frame)
        // empty rootViewController is required
        win.rootViewController = UIViewController(nibName: nil, bundle: nil)
        win.backgroundColor = UIColor.white
        win.makeKeyAndVisible()
        
        let webview = UIWebView(frame: frame)
        webview.scalesPageToFit = true
        win.addSubview(webview)
        // http url is blocked by default security
        let req = URLRequest(url: URL(string: "https://google.com/")!)
        webview.loadRequest(req)

        // it should keep as member (avoid gc?)
        window = win
        return true
    }
}

CommandLine.unsafeArgv.withMemoryRebound(
  to: UnsafeMutablePointer<Int8>.self, capacity: Int(CommandLine.argc)) {
    argv -> Void in
    UIApplicationMain(
      CommandLine.argc, argv, nil, NSStringFromClass(AppDelegate.self))
}


// references:
// http://onebigfunction.com/tools/2015/02/03/xcrun-execute-xcode-tasks-from-command-line/
// https://forums.developer.apple.com/thread/46405
// http://takuya-1st.hatenablog.jp/entry/2016/05/26/230613
// https://gist.github.com/bellbind/3175073