Class Has No Initializers Swift
I Have a Problem with Swift Class. I Have a Swift File for Uitableviewcontroller Class and Uitableviewcell Class. My Problem Is the Uitableviewcell Class, and...
I have a problem with Swift class. I have a swift file for UITableViewController class and UITableViewCell class. My problem is the UITableViewCell class, and outlets. This class has an error Class "HomeCell" has no initializers, and I don't understand this problem.
Thanks for your responses.
import Foundation
import UIKit
class HomeTable: UITableViewController, UITableViewDataSource, UITableViewDelegate {
@IBOutlet var tableViex: UITableView!
var items: [(String, String, String)] = [
("Test", "123", "1.jpeg"),
("Test2", "236", "2.jpeg"),
("Test3", "678", "3.jpeg")
]
override func viewDidLoad() {
super.viewDidLoad()
var nib = UINib(nibName: "HomeCell", bundle: nil)
tableView.registerNib(nib, forCellReuseIdentifier: "bookCell")
}
// Number row
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return self.items.count
}
// Style Cell
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var cell:UITableViewCell = self.tableView.dequeueReusableCellWithIdentifier("bookCell") as UITableViewCell
// Style here
return cell
}
// Select row
override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
// Select
}
}
// PROBLEM HERE
class HomeCell : UITableViewCell {
@IBOutlet var imgBook: UIImageView
@IBOutlet var titleBook: UILabel
@IBOutlet var pageBook: UILabel
func loadItem(#title: String, page: String, image:String) {
titleBook.text = title
pageBook.text = page
imgBook.image = UIImage(named: image)
}
}
7 Answers
You have to use implicitly unwrapped optionals so that Swift can cope with circular dependencies (parent <-> child of the UI components in this case) during the initialization phase.
@IBOutlet var imgBook: UIImageView!
@IBOutlet var titleBook: UILabel!
@IBOutlet var pageBook: UILabel!
Read this doc, they explain it all nicely.
Quick fix - make sure all variables which do not get initialized when they are created (eg var num : Int? vs var num = 5) have either a ? or !.
Long answer (reccomended) - read the doc as per mprivat suggests...
My answer addresses the error in general and not the exact code of the OP. No answer mentioned this note so I just thought I add it.
The code below would also generate the same error:
class Actor {
let agent : String? // BAD! // Its value is set to nil, and will always be nil and that's stupid so Xcode is saying not-accepted.
// Technically speaking you have a way around itπ€, you can help the compiler and enforce your value as a constant. See Option3
}
Others mentioned that Either you create initializers or you make them optional types, using ! or ? which is correct. However if you have an optional member/property, that optional should be mutable ie var. If you make a let then it would never be able to get out of its nil state. That's bad!
So the correct way of writing it is:
Must Read
Option1
class Actor {
var agent : String? // It's defaulted to `nil`, but also has a chance so it later can be set to something different || GOOD!
}
Or you can write it as: