How to Send Data as Parameter to UIButton Selector Method - ios

Question

So I'm building an app similar to Tinder where there is a card "deck" (referred to in this code as cardsDeckView) filled with UIViews (referred to in this code as cardView). Each of these "cards" display user information such as profile images (which you can cycle through), name, age, and profession. They also have a button on them that, when pressed, go to a user info screen where more information about that user is shown. Here is where I'm having trouble. I figured I could pass each user's id to each respective "card" when users are loaded on the deck, and pass this data through the button target when pressed, but I haven't found anything on Stack Overflow regarding passing parameters into button selectors in Swift. Here is my code, that essentially loads existing users with some filters, and creates cardViews with each user's info:
import UIKit
import SDWebImage
import SLCarouselView
import JGProgressHUD
class DeckVC: UIViewController {
let headerView = UIView()
let cardsDeckView = SLCarouselView(coder: NSCoder.empty())
let menuView = BottomNavigationStackView()
var users: [User] = []
var userId: String?
let hud = JGProgressHUD(style: .extraLight)
override func viewDidLoad() {
super.viewDidLoad()
hud.textLabel.text = "Loading nearby users..."
hud.layer.zPosition = 50
hud.show(in: view)
headerView.heightAnchor.constraint(equalToConstant: 70).isActive = true
menuView.heightAnchor.constraint(equalToConstant: 70).isActive = true
let stackView = UIStackView(arrangedSubviews: [headerView, cardsDeckView!, menuView])
stackView.axis = .vertical
view.addSubview(stackView)
stackView.frame = .init(x: 0, y: 0, width: 300, height: 200)
stackView.fillSuperview()
stackView.isLayoutMarginsRelativeArrangement = true
stackView.layoutMargins = .init(top: 0, left: 12, bottom: 0, right: 12)
stackView.bringSubviewToFront(cardsDeckView!)
menuView.settingsButton.addTarget(self, action: #selector(handleSettings), for: .touchUpInside)
menuView.messagesButton.addTarget(self, action: #selector(handleMessages), for: .touchUpInside)
setupUI()
}
func setupUI() {
observeUsers { (user) in
API.User.observeCurrentUser(completion: { (currentUser) in
if (user.id != API.User.CURRENT_USER?.uid) && (currentUser.preferedGender == user.gender) && (currentUser.minAge!...currentUser.maxAge! ~= user.age!) {
self.users.append(user)
DispatchQueue.main.async {
self.setupCards()
}
} else if (user.id != API.User.CURRENT_USER?.uid) && (currentUser.preferedGender == "Both") && (currentUser.minAge!...currentUser.maxAge! ~= user.age!) {
self.users.append(user)
DispatchQueue.main.async {
self.setupCards()
}
}
})
}
}
func observeUsers(completion: #escaping (User) -> Void) {
API.User.REF_USERS.observe(.childAdded) { (snapshot) in
if let dict = snapshot.value as? [String : Any] {
let user = User.transformUser(dict: dict, key: snapshot.key)
completion(user)
}
}
}
#objc func handleSettings() {
let transition = CATransition()
transition.duration = 0.3
transition.type = CATransitionType.push
transition.subtype = CATransitionSubtype.fromLeft
transition.timingFunction = CAMediaTimingFunction(name:CAMediaTimingFunctionName.easeInEaseOut)
view.window!.layer.add(transition, forKey: kCATransition)
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let profileVC = storyboard.instantiateViewController(withIdentifier: "ProfileVC")
self.present(profileVC, animated: true, completion: nil)
}
#objc func handleMessages() {
let transition = CATransition()
transition.duration = 0.3
transition.type = CATransitionType.push
transition.subtype = CATransitionSubtype.fromRight
transition.timingFunction = CAMediaTimingFunction(name:CAMediaTimingFunctionName.easeInEaseOut)
view.window!.layer.add(transition, forKey: kCATransition)
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let messagesVC = storyboard.instantiateViewController(withIdentifier: "MessagesVC")
self.present(messagesVC, animated: true, completion: nil)
}
#objc func moreInfoTapped() {
let userDetailsController = UserDetailsVC()
userDetailsController.userId = userId
present(userDetailsController, animated: true, completion: nil)
}
#objc func messageUserTapped() {
let transition = CATransition()
transition.duration = 0.3
transition.type = CATransitionType.push
transition.subtype = CATransitionSubtype.fromRight
transition.timingFunction = CAMediaTimingFunction(name:CAMediaTimingFunctionName.easeInEaseOut)
view.window!.layer.add(transition, forKey: kCATransition)
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let messagesVC = storyboard.instantiateViewController(withIdentifier: "MessagesVC")
let m = MessagesVC()
m.userId = userId
self.present(messagesVC, animated: true, completion: nil)
// go to specific user chat after this transition
}
func setupCards() {
for user in users {
let gradientView = GlympsGradientView()
let barsStackView = UIStackView()
let moreInfoButton = UIButton(type: .system)
moreInfoButton.setImage(#imageLiteral(resourceName: "info_icon").withRenderingMode(.alwaysOriginal), for: .normal)
moreInfoButton.isUserInteractionEnabled = true
moreInfoButton.addTarget(self, action: #selector(moreInfoTapped), for: .touchUpInside)
let messageUserButton = UIButton(type: .system)
messageUserButton.setImage(#imageLiteral(resourceName: "message-icon2").withRenderingMode(.alwaysOriginal), for: .normal)
messageUserButton.isUserInteractionEnabled = true
messageUserButton.addTarget(self, action: #selector(messageUserTapped), for: .touchUpInside)
gradientView.layer.opacity = 0.5
let cardView = CardView(frame: .zero)
cardView.userId = user.id
userId = user.id
cardView.images = user.profileImages
if let photoUrlString = user.profileImages {
let photoUrl = URL(string: photoUrlString[0])
cardView.imageView.sd_setImage(with: photoUrl)
}
(0..<user.profileImages!.count).forEach { (_) in
let barView = UIView()
barView.backgroundColor = UIColor(white: 0, alpha: 0.1)
barView.layer.cornerRadius = barView.frame.size.height / 2
barsStackView.addArrangedSubview(barView)
barsStackView.arrangedSubviews.first?.backgroundColor = .white
}
let nametraits = [UIFontDescriptor.TraitKey.weight: UIFont.Weight.semibold]
var nameFontDescriptor = UIFontDescriptor(fontAttributes: [UIFontDescriptor.AttributeName.family: "Avenir Next"])
nameFontDescriptor = nameFontDescriptor.addingAttributes([UIFontDescriptor.AttributeName.traits: nametraits])
let agetraits = [UIFontDescriptor.TraitKey.weight: UIFont.Weight.light]
var ageFontDescriptor = UIFontDescriptor(fontAttributes: [UIFontDescriptor.AttributeName.family: "Avenir Next"])
ageFontDescriptor = ageFontDescriptor.addingAttributes([UIFontDescriptor.AttributeName.traits: agetraits])
let jobtraits = [UIFontDescriptor.TraitKey.weight: UIFont.Weight.light]
var jobFontDescriptor = UIFontDescriptor(fontAttributes: [UIFontDescriptor.AttributeName.family: "Avenir Next"])
jobFontDescriptor = jobFontDescriptor.addingAttributes([UIFontDescriptor.AttributeName.traits: jobtraits])
let attributedText = NSMutableAttributedString(string: user.name!, attributes: [.font: UIFont(descriptor: nameFontDescriptor, size: 30)])
attributedText.append(NSAttributedString(string: " \(user.age!)", attributes: [.font: UIFont(descriptor: ageFontDescriptor, size: 24)]))
if user.profession != "" && user.company != "" {
attributedText.append(NSAttributedString(string: "\n\(user.profession!) # \(user.company!)", attributes: [.font: UIFont(descriptor: jobFontDescriptor, size: 20)]))
}
cardView.informationLabel.attributedText = attributedText
// cardsDeckView.addSubview(cardView)
cardView.addSubview(gradientView)
cardView.addSubview(barsStackView)
cardView.addSubview(moreInfoButton)
cardView.addSubview(messageUserButton)
cardView.moreInfoButton = moreInfoButton
cardView.messageUserButton = messageUserButton
cardView.stackView = barsStackView
moreInfoButton.anchor(top: nil, leading: nil, bottom: cardView.bottomAnchor, trailing: cardView.trailingAnchor, padding: .init(top: 0, left: 0, bottom: 20, right: 20), size: .init(width: 50, height: 50))
messageUserButton.anchor(top: cardView.topAnchor, leading: nil, bottom: nil, trailing: cardView.trailingAnchor, padding: .init(top: 25, left: 0, bottom: 0, right: 25), size: .init(width: 44, height: 44))
barsStackView.anchor(top: cardView.topAnchor, leading: cardView.leadingAnchor, bottom: nil, trailing: cardView.trailingAnchor, padding: .init(top: 8, left: 8, bottom: 0, right: 8), size: .init(width: 0, height: 4))
barsStackView.spacing = 4
barsStackView.distribution = .fillEqually
cardView.fillSuperview()
gradientView.fillSuperview()
hud.textLabel.text = "All done! \u{1F389}"
hud.dismiss(afterDelay: 0.0)
self.cardsDeckView?.appendContent(view: cardView)
}
}
}
extension NSCoder {
class func empty() -> NSCoder {
let data = NSMutableData()
let archiver = NSKeyedArchiver(forWritingWith: data)
archiver.finishEncoding()
return NSKeyedUnarchiver(forReadingWith: data as Data)
}
}
extension Array {
public mutating func appendDistinct<S>(contentsOf newElements: S, where condition:#escaping (Element, Element) -> Bool) where S : Sequence, Element == S.Element {
newElements.forEach { (item) in
if !(self.contains(where: { (selfItem) -> Bool in
return !condition(selfItem, item)
})) {
self.append(item)
}
}
}
}
See setupUsers(), and see how the cardView is being created with buttons. How do I get these userIds from the cardViews and pass them to the UserDetails ViewController once the moreInfo button is pressed? Could I add target/selector to these buttons in the cardView? Any suggestions would help! Thanks!

Answer 1

This will definitely works!
In setupCards() function, use below code as follows:
Button layer's name is of type String which will contain your user id and catch it further using it's layer's name.
moreInfoButton.layer.name = user.id
moreInfoButton.addTarget(self, action: #selector(moreInfoTapped(_:)), for: .touchUpInside)
In moreInfoTapped selector method, add parameters as mentioned below and pass it further to desired controller.
#objc func moreInfoTapped(_ sender: UIButton) {
let userDetailsController = UserDetailsVC()
userDetailsController.userId = sender.layer.name
present(userDetailsController, animated: true, completion: nil)
}

Answer 2

There are two problems.
First, the thing you want to do is impossible. You cannot pass extra data into an target/action button event call, because it is not your call. It is Cocoa's call.
Second, your action method signature is defective:
#objc func moreInfoTapped() {
The correct signature is:
#objc func moreInfoTapped(_ sender:Any) {
If you write the action method that way, you can retrieve the sender — the particular button that was tapped. Now you can work out what button this is and where it is, and so forth, and figure out what data you want to pass in response.

Answer 3

What you can do is Create a Custom class of UIButton. Create your required variables in that custom button class.
Pass your userId, add addTarget.
moreInfoButton.userId = user.id
moreInfoButton.addTarget(self, action: #selector(moreInfoTapped(_:)), for: .touchUpInside)
class CustomButton: UIButton {
var userId: String?
}
#objc func moreInfoTapped(_ sender: CustomButton) {
print(sender.userId)
}

Answer 4

You don't send parameters to button selectors. There is a fixed method signature for IBAction methods.
The IBAction is a method of the target (usually the view controller). The target should hold the additional state data you need to decide what to do.
You posted a lot of code without much explanation and I don't have time to go through that code and figure it out.
I gather you have a button action on one view controller that needs to link to another view controller. The first view controller should know the userIDs that it need to send to the other view controller. The first view controller should have instance variables that give it access to that information. Your IBAction methods have access to the instance variables of the object that implements those IBActions.