SearchController filtering problem in TableView - ios

Question

I've next model:
struct HashTags {
var title = ""
var tags = [String]()
}
and I try use UISearchController for seach text in tags array.
I impelemented UISearchController in my TableViewController:
class TagsController: UITableViewController {
var hashtags = [HashTags]()
var filtered = [HashTags]()
let searchController = UISearchController(searchResultsController: nil)
var searchBarIsEmpty: Bool {
guard let text = searchController.searchBar.text else { return false }
return text.isEmpty
}
var isFiltering: Bool {
return searchController.isActive && !searchBarIsEmpty
}
override func viewDidLoad() {
super.viewDidLoad()
searchController.searchResultsUpdater = self
searchController.obscuresBackgroundDuringPresentation = false
searchController.searchBar.placeholder = "Search"
navigationItem.searchController = searchController
definesPresentationContext = true
}
override func numberOfSections(in tableView: UITableView) -> Int {
if isFiltering {
return filtered.count
}
return hashtags.count
}
override func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
if isFiltering {
return filtered[section].title
}
return hashtags[section].title
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if isFiltering {
return filtered[section].tags.count
}
return 1
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Tags", for: indexPath)
var item = HashTags()
if isFiltering {
item = filtered[indexPath.section]
} else {
item = hashtags[indexPath.section]
}
let tags = item.tags
cell.textLabel?.text = tags.joined(separator: ", ")
return cell
}
}
extension TagsController: UISearchResultsUpdating {
func updateSearchResults(for searchController: UISearchController) {
filterContentForSearchText(searchController.searchBar.text!)
}
func filterContentForSearchText(_ searchText: String) {
filtered = hashtags.filter({ (hashtag: HashTags) -> Bool in
return hashtag.tags.contains(searchText.lowercased())
})
tableView.reloadData()
}
}
But it doesn't work as it should and when I start type text I receive blank screen. I need UISearchController work correctctly and search for text in HashTags tags arrays, showing correct number of sections and rows.