Swift - Dispatch Work Item to show search bar typeahead results

SearchViewController.swift

import UIKit

class SearchViewController: UIViewController {
    
    private var searchWorkItem: DispatchWorkItem?

    override func viewDidLoad() {
        super.viewDidLoad()
    }
    
    private func search(withText text: String) {
        searchWorkItem?.cancel()
        
        let task = DispatchWorkItem { [weak self] in
            guard let self = self else { return }
            self.performSearch(with: text)
        }
        
        searchWorkItem = task
        
        // Excute the workitem after 0.3 seconds. 
        DispatchQueue.main.asyncAfter(deadline: .now()+0.3, execute: task)
    }
    
    private func performSearch(with text: String) {
        // Make API request with search text
    }
}

extension SearchViewController: UISearchBarDelegate {
    func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
        search(withText: searchText)
    }
}