Handle URIs with custom schemes on macOS

HandleURI.swift

// After your application launches, register to handle Apple Events
func applicationDidFinishLaunching(_ aNotification: Notification)
{
	let appleEventManager = NSAppleEventManager.shared()
	
	appleEventManager.setEventHandler(self,
	                                  andSelector: #selector(AppDelegate.handleGetURLEvent(_:withReplyEvent:)),
	                                  forEventClass: AEEventClass(kInternetEventClass),
	                                  andEventID: AEEventID(kAEGetURL))
}
	
// When the Apple Event is handed to your app, get the URI from it
func handleGetURLEvent(_ event: NSAppleEventDescriptor, withReplyEvent replyEvent: NSAppleEventDescriptor)
{
	let uriString = event.paramDescriptor(forKeyword: keyDirectObject)?.stringValue!
	
	print("\(uriString)")
}

Info.plist

<key>CFBundleURLTypes</key>
<array>
	<dict>
		<key>CFBundleURLName</key>
		<string>MyScheme</string>
		<key>CFBundleURLSchemes</key>
		<array>
			<string>myscheme</string>
		</array>
	</dict>
</array>

OpenURI.swift

import Cocoa

NSWorkspace.shared().open(URL(string: "myscheme://path/to/whatever")!)

In your Info.plist, add the content above to the top-level dictionary