Search functionality is not working in table view

Question

I have created a search bar programmatically and I also defined the search function as well. But the problem is when I enter the text into the search bar, it is not filtering the data. I have set the filtered data into the viewDidLoad method.

Here is the view model code.

enum MoviesViewModelState {
    case loading
    case loaded([Movie])
    case error

    var movies: [Movie] {
        switch self {
        case .loaded(let movies):
            return movies
        case .loading, .error:
            return []
        }
    }
}

final class MoviesViewModel {
    
    private let apiManager: APIManaging
    
    init(apiManager: APIManaging = APIManager()) {
        self.apiManager = apiManager
    }
    
    var updatedState: (() -> Void)?
    
    var state: MoviesViewModelState = .loading {
        didSet {
            updatedState?()
        }
    }
    
    func fetchData() {
        apiManager.execute(Movie.topRated) { [weak self] result in
            switch result {
            case .success(let page):
                self?.state = .loaded(page.results)
            case .failure:
                self?.state = .error
            }
        }
    }
}

Here is the view controller code.

import UIKit

final class MoviesViewController: UITableViewController, UISearchResultsUpdating {
    
    private let viewModel: MoviesViewModel
    private var filteredData: [Movie] = []
    var searchViewController: UISearchController!
    
    init(viewModel: MoviesViewModel) {
        self.viewModel = viewModel
        super.init(nibName: nil, bundle: nil)
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        title = LocalizedString(key: "movies.title")

        NotificationCenter.default.addObserver(self, selector: #selector(textSizeChanged), name: UIContentSizeCategory.didChangeNotification, object: nil)
        filteredData = viewModel.state.movies
        searchViewController = UISearchController(searchResultsController: nil)
        searchViewController.searchResultsUpdater = self
        
        configureSearchBar()
        configureTableView()
        updateFromViewModel()
        bindViewModel()
        viewModel.fetchData()
    }
    
    override func viewDidAppear(_ animated: Bool) {
        searchViewController.searchResultsUpdater = self
        navigationItem.searchController = searchViewController
        navigationItem.hidesSearchBarWhenScrolling = false
        definesPresentationContext = true
    }

    func updateSearchResults(for searchController: UISearchController) {
        let data = viewModel.state.movies
        if let searchText = searchController.searchBar.text {
            filteredData = searchText.isEmpty ? data : filteredData
        
            tableView.reloadData()
        }
    }

    private func configureTableView() {
        tableView.dm_registerClassWithDefaultIdentifier(cellClass: MovieCell.self)
        tableView.rowHeight = UITableView.automaticDimension

        refreshControl = UIRefreshControl()
        refreshControl?.addTarget(self, action: #selector(refreshData), for: .valueChanged)
    }

    private func bindViewModel() {
        viewModel.updatedState = { [weak self] in
            guard let self else { return }
            DispatchQueue.main.async {
                self.updateFromViewModel()
            }
        }
    }

    private func updateFromViewModel() {
        switch viewModel.state {
        case .loading, .loaded:
            tableView.reloadData()
        case .error:
            showError()
        }
        refreshControl?.endRefreshing()
    }

    private func showError() {
        let alertController = UIAlertController(title: "", message: LocalizedString(key: "movies.load.error.body"), preferredStyle: .alert)
        let alertAction = UIAlertAction(title: LocalizedString(key: "movies.load.error.actionButton"), style: .default, handler: nil)
        alertController.addAction(alertAction)
        present(alertController, animated: true, completion: nil)
    }

    @objc private func refreshData() {
        viewModel.fetchData()
    }

    @objc private func textSizeChanged() {
        tableView.reloadData()
    }

    private func configureSearchBar() {

        let searchTextField = searchViewController.searchBar.searchTextField
        searchTextField.attributedPlaceholder = NSAttributedString(string: "Search", attributes: [.font: UIFont.Body.medium, .foregroundColor: UIColor.Text.charcoal])
        searchTextField.font = UIFont(name: "Poppins-Regular", size: 16)
        searchTextField.backgroundColor = UIColor(red: 248 / 255.0, green: 248 / 255.0, blue: 248 / 255.0, alpha: 1)
        searchTextField.borderStyle = .none
        searchTextField.layer.borderColor = UIColor.black.withAlphaComponent(0.08).cgColor
        searchTextField.layer.borderWidth = 1.0
        searchTextField.layer.cornerRadius = 8

        searchViewController.searchBar.setLeftImage(UIImage(named: "Search"))
        searchViewController.searchBar.barTintColor = .clear
        searchViewController.searchBar.setImage(UIImage(named: "Filter"), for: .bookmark, state: .normal)
        searchViewController.searchBar.showsBookmarkButton = true
        searchViewController.searchBar.delegate = self
        searchViewController.searchBar.tintColor = UIColor.Brand.popsicle40
    }
}

// MARK: - UITableViewDataSource
extension MoviesViewController {

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

    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell: MovieCell = tableView.dm_dequeueReusableCellWithDefaultIdentifier()

        let movie = filteredData[indexPath.row]
        cell.configure(movie)

        return cell
    }

}

// MARK: - UITableViewControllerDelegate
extension MoviesViewController {

    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        let movie = viewModel.state.movies[indexPath.row]
        let viewModel = MoviesDetailsViewModel(movie: movie, apiManager: APIManager())
        let viewController = MovieDetailsViewController(viewModel: viewModel)
        self.navigationController?.pushViewController(viewController, animated: true)
    }
}

extension MoviesViewController: UISearchBarDelegate {
    func searchBarBookmarkButtonClicked(_ searchBar: UISearchBar) {
        
    }
}

Here is the screenshot of the result.

Answer 1

Here is solution I have used to fixed it.

func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
        filteredMovie = []
        if searchText == "" {
            filteredMovie = viewModel.state.movies
        }
        for movie in viewModel.state.movies {
            if movie.title.uppercased()
                .contains(searchText.uppercased()) {
                filteredMovie.append(movie)
            }
        }
        tableView.reloadData()
    }