I have a subclass of UIView named BaseView. In subclass of BaseView I create didSet with some code. In UIViewController I init this subclass of BaseView and he doesn't invoke his didSet
BaseView code:
class BaseView: UIView {
override init(frame: CGRect) {
super.init(frame: frame)
setupViews()
}
func setupViews() { }
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
Subclass of BaseView code:
class DetailProductView: BaseView {
var product: Product? {
didSet {
productImage.image = UIImage(named: (product?.productImageName)!)
productTitle.text = product?.title
productCompositionLabel.text = product?.description
productPriceLabel.text = "₽" + product!.productPrice!.stringValue
productWeightLabel.text = product!.productWeight!.stringValue + "г."
}
}
UIViewController code:
class DetailProductController: UIViewController {
var product: Product?
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .white
let productView = DetailProductView(frame: self.view.bounds)
view.addSubview(productView)
view.layoutSubviews()
}
}
Everything is correct. You created instance of DetailProductView, but you never set any value to it’s product property. Thus didSet was never called (cause you didn’t set anything).
If you want it to be called you should set any value to this property.
Related
I have a class called UIViewControllerModel which I like to initialize backgroundColor for this class, I am sure this a syntax error, need help for correction please.
class UIViewControllerModel: UIViewController {
var backgroundColor: UIColor
required init(backgroundColor: UIColor) {
super.init()
self.backgroundColor = backgroundColor
}
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = backgroundColor
}
}
The required initializer is not the right one -- because your class is a subclass of UIViewController, you need a required init?(coder: NSCoder). You can put your custom initializer that sets backgroundColor in separate init.
Also, instead of viewDidLoad, use loadView for your custom View Controllers that you make in code. This is how you do it:
class UIViewControllerModel: UIViewController {
var backgroundColor: UIColor
/// Put your custom argument labels here, not inside the `required init?`
init(backgroundColor: UIColor) {
self.backgroundColor = backgroundColor
super.init(nibName: nil, bundle: nil)
}
/// This is in case the View Controller is loaded from the Storyboard
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
/// Use this instead of viewDidLoad
override func loadView() {
/**
Instantiate the base `view`.
*/
view = UIView()
view.backgroundColor = backgroundColor
}
}
let modelVC = UIViewControllerModel(backgroundColor: UIColor.blue)
self.present(modelVC, animated: true)
Result:
Try this
class UIViewControllerModel: UIViewController {
var backgroundColor: UIColor
init(backgroundColor: UIColor) {
self.backgroundColor = backgroundColor
super.init(nibName: nil, bundle: nil)
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func loadView() {
self.view.backgroundColor = backgroundColor
}
}
I have an XIB with a UILabel to it. I have referenced the UILabel to a UIView class that I have created. I can change the label using label.text = "hi" when initializing the view. When I try and call a change from another class it doesn't change the UILabel on screen (but if I print label.text it shows as what I set it to). I cannot make the UILabel load the text when initializing as the text could be changed by the user at any time. (switchText() is called from a UITableCell)
2nd class
class Second {
func switchText() {
let first = First()
DispatchQueue.main.async {
first.label.text = "bye"
}
}
}
1st class
class First: UIView {
let kCONTENT_XIB_NAME = "First"
#IBOutlet var label: UILabel!
#IBOutlet var contentView: UIView!
override init(frame: CGRect) {
super.init(frame: frame)
commonInit()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
commonInit()
}
func commonInit() {
Bundle.main.loadNibNamed(kCONTENT_XIB_NAME, owner: self, options: nil)
contentView.fixInView(self)
}
override func awakeFromNib() {
super.awakeFromNib()
}
}
Also, in my XIB I have my UIView hooked up to File's Owner and contentView inside my UIView class. My label outlet goes to file's owner and then to the UIView class where it is declared as label.
You are not really changing the text on your First() class. What your switchText() function does is create another reference of the class named First and then set the text of the label for that new reference.
let first = First()
DispatchQueue.main.async {
first.label.text = "bye"
}
What you can do is make your switchText() function conform to a protocol then call it on your First() class through a delegate.
protocol SecondClassDelegate {
func didSwitchText(editedText: String)
}
class Second {
var delegate: SecondClassDelegate!
func switchText() {
delegate.didSwitchText("bye")
}
}
Now you can add this to your First() class
class First: SecondClassDelegate {
func didSwitchText(editedText: String) {
label.text = editedText
}
}
Just don't forget to set the delegate wherever you're setting your Second() class
let second = Second()
second.delegate = self
I suggest reading about this for a better understanding of delegates. https://www.appcoda.com/swift-delegate/
I'm trying to achieve something I'm not sure if it's doable. I have a xib for UITableViewCell that has a UIButton in it with custom class assigned in storyboard i.e MainButtonSuperClass. In UITableViewCell.swift outlet is connected like following,
#IBOutlet weak var button: MainButtonSuperClass!
Many different controllers are configuring this TableViewCell but button's UI will be different for all those controllers as defined in subclass i.e.
final class MainButtonSubClass: MainButtonSuperClass {
override func configure(){//different style of button }
}
How can I achieve this? so far I have tried following,
let button: MainButtonSuperClass = MainButtonSubClass()
button.configure()
cell.button = button
But this doesn't pick the style
EDIT:
//tableview cell
class TableViewCell: UITableViewCell {
#IBOutlet weak var button: MainButtonSuperClass!
}
//Controller A wants default style of superclass (MainButtonSuperClass)
func configureButton(buttonCell: TableViewCell) {
buttonCell.button.configure() //works
}
//Controller B wants different style of subclass (MainButtonSubClass)
func configureButton(buttonCell: TableViewCell) {
let button: MainButtonSuperClass = MainButtonSubClass()
button.configure()
cell.button = button // doesn't work or adopts the style
}
//Custom button's classes
final class MainButtonSuperClass: UIButton {
override func configure(){//styled button }
}
final class MainButtonSubClass: MainButtonSuperClass {
override func configure(){//different style of button }
}
Ok understand, let's try this
class CustomClass: UIButton {
class Type1Class: UIButton {
// Do all the setup here
override init(frame: CGRect) {
super.init(frame: frame)
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
class Type2Class: UIButton {
// Do all the setup here
override init(frame: CGRect) {
super.init(frame: frame)
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
}
Then you can initialize it with the following:
#IBOutlet weak var button: CustomClass.Type1Class!
Hope it helps!
I found the solution. I will not use IBOutlet but just a property of UIButton that I will change dynamically with factory method. With IBOutlet it's not possible.
I often use this pattern when creating UIViewController/UIView pairs. It would be nice if I could define a template in Xcode so that I could click New File -> [template] and generate a MyViewController.swift and MyView.swift like in the example below.
MyViewController.swift
class MyViewController: UIViewController {
override func loadView() {
self.view = MyView()
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
}
extension MyViewController : MyViewDelegate
{
// Provide data, pop off a navigation stack, etc
}
MyView.swift
protocol MyViewDelegate : class {
}
class MyView: UIView
{
weak var delegate : MyViewDelegate?
// MARK: - Initialization
override init(frame: CGRect) {
super.init(frame: frame)
setup()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
setup()
}
func setup()
{
// Configure views
// Assemble
}
}
I want to put all subview properties and my subview setup code in a UIView subclass and load that into my UIViewController subclass using loadView(). Then access the UIView subclass members without casting the view property of UIViewController all the time.
This is my UIView subclass AwesomeClass
class AwesomeView: UIView {
lazy var testView:UIView = {
let view = UIView()
view.backgroundColor = UIColor.red
self.addSubview(view)
return view
}()
override init(frame: CGRect) {
super.init(frame: frame)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func layoutSubviews() {
super.layoutSubviews()
testView.frame = CGRect(x: 10
, y: 10
, width: self.bounds.size.width - 20
, height: 100)
}
}
And my UIViewController subclass AwesomeViewController
class AwesomeViewController: UIViewController {
override func loadView() {
let view = AwesomeView()
self.view = view
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
I could do something like:
var subclassedView:AwesomeView {
get {
return self.view as! AwesomeView
}
}
and
subclassedView.testView.backgroundColor = UIColor.blue
But is there a way to call testView directly with self.view in the AwesomeViewController?
Edit:
What I am looking for is Covariant return type in swift.
You can you something like this:
Instantiate an instance of AwesomeViewController in AwesomeView
class AwesomeView: UIView {
var exampleColorVariable:UIColor?
//here you instantiate your view controller
var awesomeViewController = AwesomeViewController()
lazy var testView:UIView = {
let view = UIView()
view.backgroundColor = UIColor.red
self.addSubview(view)
return view
}()
override init(frame: CGRect) {
super.init(frame: frame)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func layoutSubviews() {
super.layoutSubviews()
testView.frame = CGRect(x: 10
, y: 10
, width: self.bounds.size.width - 20
, height: 100)
}
}
then you can access any method in AwesomeView changing a little bit your code
class AwesomeViewController: UIViewController {
lazy var awesomeView: AwesomeView = {
let view = AwesomeView()
view.awesomeViewController = self
return view
}()
func setupView() {
view.addSubview(awesomeView)
// your constraints here
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
setupView()
// NOW YOU CAN ACCESS ANY METHOD IN YOUR VIEW awesomeView.yourFunction()
// or you access that variable
awesomeView.exampleColorVariable = .red // you can now omit UIColor in swift3
}
}