FB13705327

TextField binded value stops changing after field is empty

Basic Information

Which platform is most relevant for your report?

iOS

Which technology does your report involve?

SwiftUI

What type of feedback are you reporting?

Incorrect/Unexpected Behavior

What build does the issue occur on?

iOS 17.4 Seed 3 (21E5200d)

Where does the issue occur?

On device

Description

• Run the given code.
• Try typing some numbers, and see the binded value update.
• Delete the numbers until the field is empty. The value is correctly set to nil.
• Try typing some numbers again, but this time the binded value won't update.
• I would correctly expect the binded value to be set to nil when empty, but I would also expect the input to work just as normal after.

Evidence

Visual

Demo	Workaround

Code

AppleFeedback/FB13705327/demo.swift

Lines 1 to 30 in 013618a

	import SwiftUI
	struct ContentView: View {
	private static let formatter: NumberFormatter = {
	let formatter = NumberFormatter()
	formatter.numberStyle = .decimal
	formatter.usesGroupingSeparator = false
	return formatter
	}()
	@State private var value: Double? = 3
	var body: some View {
	VStack {
	TextField("Value", value: $value, formatter: Self.formatter)
	.textFieldStyle(.roundedBorder)
	.keyboardType(.decimalPad)
	if let value {
	Text("Value = \(value)")
	} else {
	Text("Value doesn't exist")
	}
	}
	}
	}
	#Preview {
	ContentView()
	}

AppleFeedback/FB13705327/workaround.swift

Lines 1 to 65 in 013618a

	import SwiftUI
	struct ContentView: View {
	private static let formatter: NumberFormatter = {
	let formatter = NumberFormatter()
	formatter.numberStyle = .decimal
	formatter.usesGroupingSeparator = false
	return formatter
	}()
	@FocusState private var focused: Bool
	@State private var value: Double? = 3
	@State private var valueString = Self.doubleToString(3)
	var body: some View {
	VStack {
	TextField("Value", text: valueBinding())
	.textFieldStyle(.roundedBorder)
	.keyboardType(.decimalPad)
	.focused($focused)
	if let value {
	Text("Value = \(value)")
	} else {
	Text("Value doesn't exist")
	}
	}
	.onChange(of: focused) {
	if !focused {
	valueString = value.map(Self.doubleToString) ?? ""
	}
	}
	}
	private func valueBinding() -> Binding<String> {
	Binding(
	get: {
	valueString
	},
	set: { new in
	if new.isEmpty {
	value = nil
	valueString = ""
	} else if let newValue = Double(new) {
	value = newValue
	valueString = Self.doubleToString(newValue)
	// May be needed in the case that it is set more than once
	if new.hasSuffix(Self.formatter.decimalSeparator) {
	valueString.append(Self.formatter.decimalSeparator)
	}
	}
	}
	)
	}
	private static func doubleToString(_ value: Double) -> String {
	let number = NSNumber(value: value)
	return Self.formatter.string(from: number)!
	}
	}
	#Preview {
	ContentView()
	}