Recursive Menu Swift

RecursivePlayground.swift

import UIKit

struct MenuItem {
    var title = ""
    var children: [MenuItem]?
}

struct Menu {
    var title = ""
    var items: [MenuItem] = []
}

var items = [
    MenuItem(
        title: "Item 1",
        children: [
            MenuItem(title: "Item 1-1", children: []),
            MenuItem(title: "Item 1-2", children: [
                MenuItem(title: "Item 1-2-1", children: []),
            ]),
        ]),
    MenuItem(
        title: "Item 2",
        children: []),
    MenuItem(
        title: "Item 3",
        children: [
            MenuItem(title: "Item 3-1", children: [
                MenuItem(
                    title: "Item 3-1-1",
                    children: [
                        MenuItem(title: "Item 3-1-1-1", children: [])
                    ]),
            ]),
        ])
]

var menu = Menu(title: "/", items: items)

import UIKit
import PlaygroundSupport
import Foundation

class TableViewController: UITableViewController {
    var menuItems: [String] = []
    var level = 0

/*** IMPORTANT STUFF ***/  
  
    func buildMenu(_  menu: Menu) {
        menuItems.append(menu.title)
        getChildren(menu.items)
    }

    func getChildren(_ items: [MenuItem]) {
        for item in items {
            level += 1
            let prefix = String(repeating: "\t", count: level)
            menuItems.append(prefix + " -> " + item.title)
            if let children = item.children {
                getChildren(children)
            }
        }
        level -= 1
        return
    }

/*** END OF IMPORTANT STUFF ***/  

    override func viewDidLoad() {
        super.viewDidLoad()
        buildMenu(menu)
        tableView.register(UITableViewCell.self, forCellReuseIdentifier: "cell")
    }

    override func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }

    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return menuItems.count
    }

    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as UITableViewCell
        cell.textLabel?.text = menuItems[indexPath.row]
        return cell
    }
}

let controller = TableViewController()
PlaygroundPage.current.liveView = controller