Updating Realm through a custom button on the UITableViewCell - swift

Question

I have a tableview of "Books" that are stored in Realm. I want to set the "CurrentBook" property to "True" when hitting a button on a custom UITableViewCell.
I believe my error has something to do with getting the correct book value in "func selectCurrentBook", when I use an optional like below nothing happens.
#objc func selectCurrentBook(sender: UIButton) {
try! realm.write {
book?.currentlyReading = true
}
}
When I don't use an optional for book and use book.currentlyReading = true I get the error "Unexpectedly found nil while implicitly unwrapping an Optional value:"
Am I incorrectly passing the book value somewhere? I can't seem to find out how. Maybe I'm delegating wrong?
My TableViewCell is:
import UIKit
import RealmSwift
protocol MyBooksDelegate {
func currentlyReadingButton()
}
class MyBooksTableViewCell: UITableViewCell {
let realm = try! Realm()
#IBOutlet weak var titleLabel: UILabel!
#IBOutlet weak var authorLabel: UILabel!
#IBOutlet weak var smallThumbnailImageView: UIImageView!
#IBOutlet weak var currentlyReadingButton: UIButton!
#IBAction func currentlyReadingButton(_ sender: Any) {
}
private var book: Book!
func loadImage(smallThumbnailURL: String) {
let imageURL = URL(string: smallThumbnailURL ?? "")
smallThumbnailImageView.sd_setImage(with: imageURL)
}
func configureCell(book: Book, delegate: MyBooksDelegate?) {
titleLabel.text = book.bookTitle
authorLabel.text = book.bookAuthor
loadImage(smallThumbnailURL: book.bookSmallThumbnailImageURL)
currentlyReadingButton.addTarget(self, action: #selector(selectCurrentBook(sender:)), for: .touchUpInside)
}
#objc func selectCurrentBook(sender: UIButton) {
try! realm.write {
book?.currentlyReading = true
}
}
}
My View Controller with TableView is :
import SwiftyJSON
import RealmSwift
class BooksViewController: UIViewController, UITextFieldDelegate, UITableViewDataSource, UITableViewDelegate {
#IBOutlet weak var myBooksTableView: UITableView!
let realm = try! Realm()
var books: Results<Book>?
// Search Bar Properties
var searchParameter = "intitle"
var booksArray: [Book] = []
override func viewDidLoad() {
super.viewDidLoad()
loadBooks()
// Setting up the TableView
self.myBooksTableView.delegate = self
self.myBooksTableView.dataSource = self
self.myBooksTableView.rowHeight = 120.0
// Setup Title
title = "My Books"
// navigationController?.navigationBar.prefersLargeTitles = true
}
override func viewWillAppear(_ animated: Bool) {
navigationController?.navigationBar.barStyle = .black
loadBooks()
}
func loadBooks() {
books = realm.objects(Book.self).sorted(byKeyPath: "DateCreated", ascending: false)
myBooksTableView.reloadData()
}
// TABLEVIEW
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return books?.count ?? 1
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if let cell = tableView.dequeueReusableCell(withIdentifier: "MyBooksTableViewCell", for: indexPath) as? MyBooksTableViewCell {
cell.configureCell(book: (books?[indexPath.row])!, delegate: self as? MyBooksDelegate)
// cell.selectionStyle = UITableViewCell.SelectionStyle.none
return cell
} else {
return UITableViewCell()
}
}
func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
return true
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
self.performSegue(withIdentifier: "myBooksTOMyBooksDetail", sender: self)
myBooksTableView.deselectRow(at: indexPath, animated: true)
}
And my Book Model is:
class Book: Object {
#objc dynamic var bookTitle: String!
#objc dynamic var bookAuthor: String!
#objc dynamic var bookSmallThumbnailImageURL: String!
#objc dynamic var bookThumbnailImageURL: String!
#objc dynamic var bookDescription: String!
#objc dynamic var bookISBN_13: String!
#objc dynamic var currentlyReading = false
#objc dynamic var DateCreated = Date()
#objc dynamic var WordID = UUID().uuidString
// words
let words = List<Word>()
override static func primaryKey() -> String? {
return "WordID"
}
}

Answer 1

The most compatible syntax is
currentlyReadingButton.addTarget(self, action: #selector(selectCurrentBook), for: .touchUpInside)
and
#objc func selectCurrentBook(_ sender: UIButton) {
However as the cell is custom anyway I'd prefer an IBAction over target/action
And the protocol MyBooksDelegate seems to be unused.
Side note:
Force unwrap the cell
let cell = tableView.dequeueReusableCell(withIdentifier: "MyBooksTableViewCell", for: indexPath) as! MyBooksTableViewCell
A crash – with report – reveals a design mistake which can be fixed instantly. With the if let you'll see nothing and have no clue why.
Update:
The crash occurs because you don't set book in the cell, add the first line after the {
func configureCell(book: Book, delegate: MyBooksDelegate?) {
self.book = book
titleLabel.text = book.bookTitle
...