How to create custom menus using UIMenuController

Swift version: 5.10

Paul Hudson @twostraws May 28th 2019

iOS has a built-in menu system that, while useful, doesn't actually get much use – because users don't expect to see it, developers don't use it, thus making it even less likely that users expect to see it.

Anyway, if you want to attach multiple actions to elements in your UI – pieces of text in a text view or web view, table view rows, and so on – you might find iOS menus are for you, so you need to turn to UIMenuController. This has extremely simple API: you just create a UIMenuItem object for every action you want, then register them all and wait for the user to do something.

Below is a complete example for a view controller that has a web view inside it – you'll need to create that in your storyboard. The code sets up a new menu item named "Grok" that runs the runGrok() method when tapped. I've made it do something real: when the user selects some text, they tap Grok to have that printed out to the Xcode console.

Here's the code:

class ViewController: UIViewController, UITextViewDelegate {
    @IBOutlet var webView: UIWebView!

    override func viewDidLoad() {
        super.viewDidLoad()

        webView.loadHTMLString("<p>Hello, world!</p>", baseURL: nil)
        enableCustomMenu()
    }

    func enableCustomMenu() {
        let lookup = UIMenuItem(title: "Grok", action: #selector(runGrok))
        UIMenuController.shared.menuItems = [lookup]
    }

    func disableCustomMenu() {
        UIMenuController.shared.menuItems = nil
    }

    @objc func runGrok() {
        let text = webView.stringByEvaluatingJavaScript(from: "window.getSelection().toString();")
        print(text)
    }
}