UISearchBar and your UI

Jul 2, 2019

1*xFFtWEQHa276oEAtmjeh6A 🔭🔮📡

Let’s say you have a wonderful ViewController and you want to add a search bar with dropdown to it. Apple provides you with a tool: UISearchBar. This tutorial will teach you to put UISearchBar and still have that wonderful layout you had. Today we’ll implement a basic level UISearchBar to get you going. Let’s start by creating a new 1-Page project and tangle a bit with the storyboard. We will add a searchbar later. This is how my looks like:

nice and clean simple storyboard Add in a new View, this will be the container for our SearchBar. We will use UISearchBar to make our storyboard easier to read. Connect an outlet of the newly created View to your ViewController. Create a new swift file, change the class to UITableViewController, then name it anything that make sense to you. This new UITableViewController will be show on the SearchViewController.

Insert just enough code to present a tableViewController.

import UIKitclass SearchTableViewController: UITableViewController {    
  var filterData: [String]!    
  override func viewDidLoad() {        
    super.viewDidLoad()    
  }    
// MARK: - Table view data source    
  override func numberOfSections(in tableView: UITableView) -> Int {    
    return 1   
  }    
  override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {        
    return filterData.count    
  }        
  override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {        
      let cell = UITableViewCell(style: .default, reuseIdentifier: "cell")
      cell.textLabel?.text = filterData[indexPath.row]        
      return cell    
    }    
  }

Add the following code to ViewController.

import UIKitclass ViewController: UIViewController {    
  @IBOutlet weak var searchBar: UISearchBar!        
  /// Search controller to help us with filtering.    
  private var searchController: UISearchController!        
  /// Secondary search results table view.    
  private var resultsTableController: SearchTableViewController!
  override func viewDidLoad() {        
    super.viewDidLoad()                
    resultsTableController = SearchTableViewController()
    resultsTableController.tableView.delegate = self                
    // 1        
    searchController = UISearchController(searchResultsController: resultsTableController)        
    searchController.searchResultsUpdater = self        
    searchController.searchBar.autocapitalizationType = .none
    // replace searchBar with searchController's searchbar
    searchBar.addSubview(searchController.searchBar)
    searchController.delegate = self
    searchController.dimsBackgroundDuringPresentation = false 
    // The default is true.        
    searchController.searchBar.delegate = self 
    // Monitor when the search button is tapped.                
    // set true to make searchbar moves to navigatoion        
    searchController.hidesNavigationBarDuringPresentation = false
    /** Search presents a view controller by applying normal view controller presentation semantics.         This means that the presentation moves up the view controller hierarchy until it finds the root         view controller or one that defines a presentation context.         */
    /** Specify that this view controller determines how the search controller is presented.         The search controller should be presented modally and match the physical size of this view controller.         */
    definesPresentationContext = true            
    }
  }
  // MARK: - UITableViewDelegateextension 
  ViewController: UITableViewDelegate {        
    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {        
      let selectedString: String        
      // 2         
      // Check to see which table view cell was selected.        
      if tableView === resultsTableController.tableView {
      selectedString = resultsTableController.filterData[indexPath.row]
    } else {            
      selectedString = ""        
    }                
    print(selectedString)                
    tableView.deselectRow(at: indexPath, animated: false)    
  }    
}
// MARK: - UISearchBarDelegate
extension ViewController: UISearchBarDelegate {
  func searchBarSearchButtonClicked(_ searchBar: UISearchBar) {
    searchBar.resignFirstResponder()
  }
}
// MARK: - UISearchControllerDelegate
// Use these delegate functions for additional control over the search controller.
extension ViewController: UISearchControllerDelegate {
   func presentSearchController(_ searchController: UISearchController) {
    // 3        
    // to move table under searchbar
    resultsTableController.view.frame = CGRect(x: 0, y: searchBar.frame.maxY, width: self.view.frame.width, height: self.view.frame.height - searchBar.frame.maxY)
    debugPrint("UISearchControllerDelegate invoked method: \(#function).")
  }
  func willPresentSearchController(_ searchController: UISearchController) {
    debugPrint("UISearchControllerDelegate invoked method: \(#function).")
  }
  func didPresentSearchController(_ searchController: UISearchController) {
    // to move content to correct location
    resultsTableController.tableView.contentInset = UIEdgeInsets(top: searchBar.frame.size.height, left: 0, bottom: 0, right: 0)
    debugPrint("UISearchControllerDelegate invoked method: \(#function).")
  }
  func willDismissSearchController(_ searchController: UISearchController) {
    debugPrint("UISearchControllerDelegate invoked method: \(#function).")
  }
  func didDismissSearchController(_ searchController: UISearchController) {
    debugPrint("UISearchControllerDelegate invoked method: \(#function).")
  }    
}
// MARK: - UISearchResultsUpdating
extension ViewController: UISearchResultsUpdating {    
  func updateSearchResults(for searchController: UISearchController) {        // Update the filtered array based on the search text.        
  let searchResults = ["abcde","cdefg","efghi","ghijk"]                
  // Strip out all the leading and trailing spaces.        
  let whitespaceCharacterSet = CharacterSet.whitespaces        
  let strippedString =            searchController.searchBar.text!.trimmingCharacters(in: whitespaceCharacterSet)                
  let filteredResults = searchResults.filter { $0.contains(strippedString) }
  // Apply the filtered results to the search results table.        
  if let resultsController = searchController.searchResultsController as? SearchTableViewController {            
  resultsController.filterData = filteredResults            
  resultsController.tableView.reloadData()        
  }    
 }    
}

Create a new SearchBarViewController. Add a searchbar to our view. Connect SearchBarViewController to our SearchTableViewController. SearchTableViewController datasource. Move SearchBarViewController tableView right under the searchBar.

Build and run. — — — — — — — — — — — — — — — — — — — — — — — — — To improve: Make SearchTableViewController a ViewController. Animation.

Confusians