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Xcode – How do I get my new text entry into a UITextfield to store when closing app?

small4
July 21, 2021
93 views
1 vote
2 Answers

I’m completely new to programming. Trying to learn Swift. I’ve created the UI for my app. A simple data entry app for weight lifting PB’s. However when I close the app my data doesn’t update to new stored values. How do assign a variable string to each UITextfield entry, which when I close the app it will display its last stored value?

import UIKit

class ViewController: UIViewController, UITextFieldDelegate {
    @IBOutlet weak var benchPressPB: UITextField!
    @IBOutlet weak var squatPB: UITextField!
    @IBOutlet weak var deadliftPB: UITextField!
    @IBOutlet weak var ohpPB: UITextField!
    @IBOutlet weak var rackPullPB: UITextField!
    @IBOutlet weak var legPressPB: UITextField!
    @IBOutlet weak var pullUpsPB: UITextField!
    override func viewDidLoad() {
        super.viewDidLoad()
        self.benchPressPB.delegate = self
        self.squatPB.delegate = self
        self.deadliftPB.delegate = self
        self.ohpPB.delegate = self
        self.rackPullPB.delegate = self
        self.legPressPB.delegate = self
        self.pullUpsPB.delegate = self
    }
    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        textField.resignFirstResponder()
        return true
    }
}

P.S this may completely wrong and long already, but currently its achieving what I want it do, just not saving new inputted data. If there’s any shorter way to get the keyboard to hide on return, let me know!

Answers

You can subclass UITextField and add a target for editing changed. Every time your text changes you can simply save its new value into user defaults. To make sure you use a unique key for each field you can override the accessibilityIdentifier and implement didSet to load the old values when you set its identifier:

import UIKit

class PersistentTextField: UITextField, UITextFieldDelegate {
    override var accessibilityIdentifier: String? {
        didSet {
            text = UserDefaults.standard.string(forKey: accessibilityIdentifier ?? "")
        }
    }
    override func didMoveToSuperview() {
        addTarget(self, action: #selector(editingChanged), for: .editingChanged)
        autocapitalizationType = .none
        autocorrectionType = .no
        delegate = self
    }
    @objc func editingChanged(_ textField: UITextField) {
        UserDefaults.standard.set(text ?? "", forKey: accessibilityIdentifier ?? "")
    }
    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        resignFirstResponder()
        return true
    }
}

Then in your view controller just make sure to set their id when your view loads:

import UIKit

class ViewController: UIViewController {
    
    @IBOutlet weak var benchPressPB: PersistentTextField!
    @IBOutlet weak var squatPB: PersistentTextField!
    @IBOutlet weak var deadliftPB: PersistentTextField!
    @IBOutlet weak var ohpPB: PersistentTextField!
    @IBOutlet weak var rackPullPB: PersistentTextField!
    @IBOutlet weak var legPressPB: PersistentTextField!
    @IBOutlet weak var pullUpsPB: PersistentTextField!


    override func viewDidLoad() {
        super.viewDidLoad()
        benchPressPB.accessibilityIdentifier = "bench press"
        squatPB.accessibilityIdentifier = "squat"
        deadliftPB.accessibilityIdentifier = "dead lift"
        ohpPB.accessibilityIdentifier = "ohp"
        rackPullPB.accessibilityIdentifier = "rack pull"
        legPressPB.accessibilityIdentifier = "leg press"
        pullUpsPB.accessibilityIdentifier = "pull ups"
    }
}

Your current code doesn’t do anything with the values a user enters into your text fields.

You should

Set up a model object to hold the values that the user enters.
In your textFieldShouldReturn, collect the user input and save it
into your model.
Decide on how you want to persist your app’s state so it restores
when the app is launched. At it’s simplest, this could be saving each
string to a different key/value pair in UserDefaults, or grouped
together in a dictionary or an array.

The code might look something like this: (not tested. Not even compiled. It will need cleanup before you can use it:

@IBOutlet weak var benchPressPB: UITextField!
@IBOutlet weak var squatPB: UITextField!
@IBOutlet weak var deadliftPB: UITextField!
@IBOutlet weak var ohpPB: UITextField!
@IBOutlet weak var rackPullPB: UITextField!
@IBOutlet weak var legPressPB: UITextField!
@IBOutlet weak var pullUpsPB: UITextField!

var textFields = [UITextField]
var textFieldKeys = [
  "benchPressPB", 
  "squatPB", 
  "deadliftPB", 
  "ohpPB", 
  "rackPullPB", 
  "legPressPB", 
  "pullUpsPB"
]
var textFieldStrings = [String]()


override func viewDidLoad() {
    super.viewDidLoad()
    
    // Note that you can hook up the delegates for your 
    // text fields in your Storyboard.
    self.benchPressPB.delegate = self
    self.squatPB.delegate = self
    self.deadliftPB.delegate = self
    self.ohpPB.delegate = self
    self.rackPullPB.delegate = self
    self.legPressPB.delegate = self
    self.pullUpsPB.delegate = self 

    textFields = [benchPressPB, squatPB, deadliftPB, ohpPB, rackPullPB, legPressPB, pullUpsPB] 
    // Read values from UserDefaults into the text fields.
    for (index, key) in textFieldKeys.enumerated() {
        let aValue = UserDefaults.standard.string(forKey: key)
        textFields[index].text = aValue
        textFieldStrings.append(aValue ?? "")
    }
        
}

func textFieldShouldReturn(_ textField: UITextField) -> Bool {
    textField.resignFirstResponder()
    let newText = textField.text
    if let index = textFields.firstIndex(of: textField) {
       textFieldStrings[index] = newText
       UserDefaults.standard.set(newText, forKey: textFieldKeys[index])
    }
    return true
}

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