Solution for iOS 14 Contextual Menu Button Missing in SwiftUI

MenuButton.swift

//
//  MenuButton.swift
//  Check Register
//
//  Created by Owen Donckers on 7/16/20.
//  Copyright © 2020 Owen Donckers. All rights reserved.
//

import SwiftUI

@available(iOS 14.0, *)
struct MenuButton: UIViewRepresentable {
    let systemImage: String
    var menuTitle: String = ""
    let actions: [Action]
        
    struct Action {
        let title: String
        var systemImage: String? = nil
        var attributes: Attributes = .default
        var action: (() -> Void)? = nil
        
        var options: Options = .default
        var children: [Action]? = nil
        
        enum Attributes {
            case `default`
            case destructive
            
            fileprivate func toUI() -> UIMenuElement.Attributes {
                switch self {
                case .destructive:
                    return .destructive
                default:
                    return .init()
                }
            }
        }
        
        enum Options {
            case `default`
            case displayInline
            case destructive
            
            fileprivate func toUI() -> UIMenu.Options {
                switch self {
                case .displayInline:
                    return .displayInline
                case .destructive:
                    return .destructive
                default:
                    return .init()
                }
            }
        }
                
        static func `default`(title: String, systemImage: String? = nil, action: @escaping () -> Void) -> Action {
            Action(title: title, systemImage: systemImage, attributes: .default, action: action)
        }
        
        static func destructive(title: String, systemImage: String? = nil, action: @escaping () -> Void) -> Action {
            Action(title: title, systemImage: systemImage, attributes: .destructive, action: action)
        }
        
        static func submenu(title: String, systemImage: String? = nil, options: Options = .default, children: [Action]) -> Action {
            Action(title: title, systemImage: systemImage, options: options, children: children)
        }
                
        fileprivate func toUI() -> UIMenuElement {
            if action != nil {
                let uiAction = UIAction(
                    title: title,
                    image: systemImage != nil ? UIImage(systemName: systemImage!) : nil,
                    attributes: attributes.toUI()
                ) { _ in self.action!() }
                
                return uiAction
            } else if children != nil {
                var submenuChildren: [UIMenuElement] = []
                for action in children! {
                    submenuChildren.append(action.toUI())
                }
                
                let uiMenu = UIMenu(
                    title: title,
                    image: systemImage != nil ? UIImage(systemName: systemImage!) : nil,
                    options: options.toUI(),
                    children: submenuChildren
                )
                
                return uiMenu
            } else {
                fatalError("Action requires action or children")
            }
        }
    }
    
    func makeUIView(context: Context) -> UIButton {
        UIButton()
    }
    
    func updateUIView(_ uiButton: UIButton, context: Context) {
        var menuChildren: [UIMenuElement] = []
        for action in actions {
            menuChildren.append(action.toUI())
        }
        
        let menu = UIMenu(
            title: menuTitle,
            children: menuChildren
        )
        
        let uiImage = UIImage(
            systemName: systemImage,
            withConfiguration: UIImage.SymbolConfiguration(scale: .large)
        )
         
        uiButton.setImage(uiImage, for: .normal)
        uiButton.role = .normal
        uiButton.menu = menu
        
        uiButton.showsMenuAsPrimaryAction = true
    }
}

Example Usage:

MenuButton(
    systemImage: "ellipsis.circle",
     menuTitle: "More buttons?",
     actions: [
        .default(title: "Add", systemImage: "plus") {
            print("Add something random")
        },
        .submenu(title: "Edit...", options: .displayInline, children: [
            .default(title: "Rename", systemImage: "pencil") {
                print("Your name is no longer proper!")
            },
            .destructive(title: "Delete", systemImage: "trash") {
                print("Don't delete me, I beg you")
            }
        ])
    ]
)