How to create UISearchBar to search option for my Tableview data using Swift?

Question

In my case, I am trying to implement search functionality for my tableview data. Here, I am loading JSON data into my Tableview section and rows. In custom cell I am showing name, I would like to create search by name. I tried below code but nothing display in my result. How to do in a proper way of search functionality.

var sections = [Section]()
var filteredNames = [Section]()
var searchController : UISearchController!

Tableview Delegates

// MARK: UITableview Delegates

    func numberOfSections(in tableView: UITableView) -> Int {
        return sections.count
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        if isFiltering {
            return filteredNames[section].result.count
        } else {
            return sections[section].result.count
        }
    }

    func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
        return sections[section].title
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell:MyCustomCell = self.tableView.dequeueReusableCell(withIdentifier: cellReuseIdentifier) as! MyCustomCell
        let item = sections[indexPath.section].result[indexPath.row]
        let filteritem = filteredNames[indexPath.section].result[indexPath.row]
        if isFiltering {
            cell.nameLabel.text = filteritem.name
        } else {
            cell.nameLabel.text = item.name
        }
        return cell
    }

SearchBarAction and Delegates

 // MARK: UISearchBar Delegates

@IBAction func searchAction(_ sender: Any) {

    searchController = UISearchController(searchResultsController: nil)
    searchController.hidesNavigationBarDuringPresentation = false
    searchController.searchBar.keyboardType = UIKeyboardType.asciiCapable
    searchController.searchBar.barTintColor = #colorLiteral(red: 0.317096545, green: 0.5791940689, blue: 0.3803742655, alpha: 1)
    searchController.searchBar.backgroundColor = #colorLiteral(red: 1.0, green: 1.0, blue: 1.0, alpha: 1.0)
    searchController.dimsBackgroundDuringPresentation = false

    // Make this class the delegate and present the search
    self.searchController.searchBar.delegate = self
    searchController.searchResultsUpdater = self
    present(searchController, animated: true, completion: nil)
}

func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
    guard let searchText = searchBar.text else {
        isFiltering = false
        return
    }
    filteredNames = sections[indexPath.section].result[indexPath.row].filter({
        return $0.lowercased().contains(searchText.lowercased())
    })
    isFiltering = filteredNames.count > 0
    self.tableView.reloadData()
}

Error: I am getting error - Use of unresolved identifier 'indexPath'; did you mean 'IndexPath'?

Answer 1

I'm taking a bit of a calculated guess here, you may need to make some amends yourself.

In my example (link provided in comments above) I am just filtering an array of names. It is more difficult if you have sections as you want to filter the items in the sections and then remove any empty sections.

So your filter method should probably look something like this:

guard let searchText = searchBar.text else {
    isFiltering = false
    return
}

self.filteredNames = sections.map({ 
    let filteredResult = $0.result.filter { $0.name.contains(searchText) }
    $0.result = filteredResult
    return $0
)).filter { !$0.result.isEmpty } 

So here you are looping through each section, then filtering the result array for matches in the search string, then removing any sections that have 0 results in.

Note you might be able to shorten that

self.filteredNames = sections.map({ 
    $0.result = $0.result.filter { $0.name.contains(searchText) }
)).filter { !$0.result.isEmpty } 

EDIT:

import UIKit
import PlaygroundSupport
import UIKit
import PlaygroundSupport

struct Section {
    let title: String
    var result: [String]
}

class ViewController: UITableViewController {

    let searchController = UISearchController(searchResultsController: nil)

    let names = [
        Section(title: "J", result: [
            "John",
            "Jason"
        ]),
        Section(title: "M", result: [
            "Martin",
            "Michael",
            "Mattew"
        ]),
        Section(title: "T", result: [
            "Terry",
            "Thomas"
        ]),
        Section(title: "S", result: ["Steven"])
    ]
    var filteredNames = [Section]()

    override func viewDidLoad() {
        super.viewDidLoad()

        self.title = "Search Example"

        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 filteredNames.count
        } else {
            return names.count
        }
    }

    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        if isFiltering() {
            return filteredNames[section].result.count
        } else {
            return names[section].result.count
        }
    }

    override func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
        if isFiltering() {
            return filteredNames[section].title
        } else {
            return names[section].title
        }
    }

    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = UITableViewCell() // don't do this, i am for example.

        var name: String
        if isFiltering() {
            name = filteredNames[indexPath.section].result[indexPath.row]
        } else {
            name = names[indexPath.section].result[indexPath.row]
        }

        cell.textLabel?.text = name
        return cell
    }

    func searchBarIsEmpty() -> Bool {
        // Returns true if the text is empty or nil
        return searchController.searchBar.text?.isEmpty ?? true
    }

    func isFiltering() -> Bool {
        return searchController.isActive && !searchBarIsEmpty()
    }

    func filterContentForSearchText(_ searchText: String, scope: String = "All") {

        filteredNames = names.map({
            let result = $0.result.filter {
                $0.localizedLowercase.contains(searchText.lowercased())
            }
            return Section(title: $0.title, result: result)
        }).filter { !$0.result.isEmpty }

        tableView.reloadData()
    }
}

extension ViewController: UISearchResultsUpdating {
    func updateSearchResults(for searchController: UISearchController) {
        filterContentForSearchText(searchController.searchBar.text!)
    }
}

let vc = ViewController()
let nav = UINavigationController()
nav.viewControllers = [vc]

PlaygroundPage.current.liveView = nav

Answer 2

First of all you are filtering sections so name the array

var filteredSections = [Section]()

filteredNames is misleading and implies that the array is [String]

A possible solution is to create new sections with the filtered content

func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
    if !searchText.isEmpty {
        filteredSections = sections.compactMap { section -> Section? in
            let filteredContent = section.result.filter {$0.name.range(of: searchText, options: .caseInsensitive) != nil }
            return filteredContent.isEmpty ? nil : Section(title: section.title, result: filteredContent)
        }
        isFiltering = true  
    } else {  
        filteredSections.removeAll()
        isFiltering = false
    }
    self.tableView.reloadData()
}

And the table view data source methods must be changed to

func numberOfSections(in tableView: UITableView) -> Int {
    return isFiltering ? filteredSections.count : sections.count
}

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    let currentSection = isFiltering ? filteredSections[section] : sections[section]
    return currentSection.result.count
}

func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
    return isFiltering ? filteredSections[section].title : sections[section].title
}

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = self.tableView.dequeueReusableCell(withIdentifier: cellReuseIdentifier, for: indexPath) as! MyCustomCell
    let section = isFiltering ? filteredSections[indexPath.section] : sections[indexPath.section]
    let item = section.result[indexPath.row]
    cell.nameLabel.text = item.name
    return cell
}