Format Currency in Textfield in Swift on Input

How to input currency format on a text field (from right to left) using Swift?

For Swift 3. Input currency format on a text field (from right to left)

override func viewDidLoad() {
    super.viewDidLoad()

    textField.addTarget(self, action: #selector(myTextFieldDidChange), for: .editingChanged)
}

@objc func myTextFieldDidChange(_ textField: UITextField) {

    if let amountString = textField.text?.currencyInputFormatting() {
        textField.text = amountString
    }
}

extension String {

    // formatting text for currency textField
    func currencyInputFormatting() -> String {
    
        var number: NSNumber!
        let formatter = NumberFormatter()
        formatter.numberStyle = .currencyAccounting
        formatter.currencySymbol = "$"
        formatter.maximumFractionDigits = 2
        formatter.minimumFractionDigits = 2
    
        var amountWithPrefix = self
    
        // remove from String: "$", ".", ","
        let regex = try! NSRegularExpression(pattern: "[^0-9]", options: .caseInsensitive)
        amountWithPrefix = regex.stringByReplacingMatches(in: amountWithPrefix, options: NSRegularExpression.MatchingOptions(rawValue: 0), range: NSMakeRange(0, self.count), withTemplate: "")
    
        let double = (amountWithPrefix as NSString).doubleValue
        number = NSNumber(value: (double / 100))
    
        // if first number is 0 or all numbers were deleted
        guard number != 0 as NSNumber else {
            return ""
        }
    
        return formatter.string(from: number)!
    }
}

Format currency in textfield in Swift on input

I modified the function from earlier today. Works great for "en_US" and "fr_FR". However, for "ja_JP", the division by 100 I do to create decimals is a problem. You will need to have a switch or if/else statement that separates currencies with decimals and those that do not have them when formatted by the formatter. But I think this gets you in the space you wanted to be.

import UIKit

class ViewController: UIViewController, UITextFieldDelegate {

    @IBOutlet weak var textField: UITextField!
    var currentString = ""

    override func viewDidLoad() {
        super.viewDidLoad()

        self.textField.delegate = self
    }

    //Textfield delegates
    func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool { // return NO to not change text

        switch string {
        case "0","1","2","3","4","5","6","7","8","9":
            currentString += string
            println(currentString)
            formatCurrency(string: currentString)
        default:
            var array = Array(string)
            var currentStringArray = Array(currentString)
            if array.count == 0 && currentStringArray.count != 0 {
                currentStringArray.removeLast()
                currentString = ""
                for character in currentStringArray {
                    currentString += String(character)
                }
                formatCurrency(string: currentString)
            }
        }
        return false
    }

    func formatCurrency(#string: String) {
        println("format \(string)")
        let formatter = NSNumberFormatter()
        formatter.numberStyle = NSNumberFormatterStyle.CurrencyStyle
        formatter.locale = NSLocale(localeIdentifier: "en_US")
        var numberFromField = (NSString(string: currentString).doubleValue)/100
        textField.text = formatter.stringFromNumber(numberFromField)
        println(textField.text )
    }
}

SwiftUI input currency format in a text field (from right to left)

I have created a currencyTextField that wraps around a UITextfield. It's not right to left, but you can modify it to be so by removing some cursor code.

Here's the demo

and here's the repo https://github.com/youjinp/SwiftUIKit

UITextField display formatted as currency without decimal

Try below code

extension ViewController: UITextFieldDelegate {

    func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {

        let text: NSString = (textField.text ?? "") as NSString
        let finalString = text.replacingCharacters(in: range, with: string)

        // 'currency' is a String extension that doews all the number styling
        amountTextField.text = finalString.currency

        // returning 'false' so that textfield will not be updated here, instead from styling extension
        return false
    }
}

extension String {
    var currency: String {
        // removing all characters from string before formatting
        let stringWithoutSymbol = self.replacingOccurrences(of: "$", with: "")
        let stringWithoutComma = stringWithoutSymbol.replacingOccurrences(of: ",", with: "")

        let styler = NumberFormatter()
        styler.minimumFractionDigits = 0
        styler.maximumFractionDigits = 0
        styler.currencySymbol = "$"
        styler.numberStyle = .currency

        if let result = NumberFormatter().number(from: stringWithoutComma) {
            return styler.string(from: result)!
        }

        return self
    }
}

UITextField to Input Money Amount

Xcode 9 • Swift 4

import UIKit

class IntegerField: UITextField {
    var lastValue = 0
    let maxValue = 1_000_000_000
    var amount: Int {
        if let newValue = Int(string.digits), newValue < maxValue {
            lastValue = newValue
        } else if !hasText {
            lastValue = 0
        }
        return lastValue
    }
    override func didMoveToSuperview() {
        textAlignment = .right
        keyboardType = .numberPad
        text = Formatter.decimal.string(for: amount)
        addTarget(self, action: #selector(editingChanged), for: .editingChanged)
    }
    @objc func editingChanged(_ textField: UITextField) {
        text = Formatter.decimal.string(for: amount)
    }
}

---

extension NumberFormatter {
    convenience init(numberStyle: Style) {
        self.init()
        self.numberStyle = numberStyle
    }
}
struct Formatter {
    static let decimal = NumberFormatter(numberStyle: .decimal)
}
extension UITextField {
    var string: String { return text ?? "" }
}

extension String {
    private static var digitsPattern = UnicodeScalar("0")..."9"
    var digits: String {
        return unicodeScalars.filter { String.digitsPattern ~= $0 }.string
    }
}

extension Sequence where Iterator.Element == UnicodeScalar {
    var string: String { return String(String.UnicodeScalarView(self)) }
}

Trying to format a UITextField to behave like a currency calculator for only numeric input in iOS

Here's a nice way to do it. Remember to set your UITextField to self in the viewDidLoad method and your header file must conform to the UITextFieldDelegate protocol

-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{

    NSString *cleanCentString = [[textField.text componentsSeparatedByCharactersInSet: [[NSCharacterSet decimalDigitCharacterSet] invertedSet]] componentsJoinedByString:@""];
    NSInteger centValue = [cleanCentString intValue];
    NSNumberFormatter * f = [[NSNumberFormatter alloc] init];
    NSNumber *myNumber = [f numberFromString:cleanCentString];
    NSNumber *result;

    if([textField.text length] < 16){
        if (string.length > 0)
        {
            centValue = centValue * 10 + [string intValue];
            double intermediate = [myNumber doubleValue] * 10 +  [[f numberFromString:string] doubleValue];
           result = [[NSNumber alloc] initWithDouble:intermediate];
        }
        else
        {
            centValue = centValue / 10;
            double intermediate = [myNumber doubleValue]/10;
            result = [[NSNumber alloc] initWithDouble:intermediate];
        }

        myNumber = result;
         NSLog(@"%ld ++++ %@", (long)centValue, myNumber);
            NSNumber *formatedValue;
            formatedValue = [[NSNumber alloc] initWithDouble:[myNumber doubleValue]/ 100.0f];
            NSNumberFormatter *_currencyFormatter = [[NSNumberFormatter alloc] init];
            [_currencyFormatter setNumberStyle:NSNumberFormatterCurrencyStyle];
            textField.text = [_currencyFormatter stringFromNumber:formatedValue];
            return NO;
    }else{

        NSNumberFormatter *_currencyFormatter = [[NSNumberFormatter alloc] init];
        [_currencyFormatter setNumberStyle:NSNumberFormatterCurrencyStyle];
        textField.text = [_currencyFormatter stringFromNumber:00];

        UIAlertView *alert = [[UIAlertView alloc]initWithTitle: @"Deposit Amount Limit"
                                                       message: @"You've exceeded the deposit amount limit. Kindly re-input amount"
                                                      delegate: self
                                             cancelButtonTitle:@"Cancel"
                                             otherButtonTitles:@"OK",nil];

        [alert show];
        return NO;
    }
    return YES;
}

Currency input in SwiftUI TextField

I have created a component that wraps around a UITextfield.

You can check it out here https://github.com/youjinp/SwiftUIKit

Here's the demo

How to make it so that user enters currency only with numbers in SwiftUI textfield, while preserving the $ and the .?

To create a currency field that allow the user to type an amount from right to left you would need an observable object (binding manager), a currency number formatter and observe every time the value changes using onChange method:

import SwiftUI

---

struct ContentView: View {
    @ObservedObject private var currencyManager = CurrencyManager(amount: 0)
    @ObservedObject private var currencyManagerUS = CurrencyManager(
        amount: 0,
        locale: .init(identifier: "en_US")
    )
    @ObservedObject private var currencyManagerUK = CurrencyManager(
        amount: 0,
        locale: .init(identifier: "en_UK")
    )
    @ObservedObject private var currencyManagerFR =  CurrencyManager(
        amount: 0,
        locale: .init(identifier: "fr_FR")
    )
    @ObservedObject private var currencyManagerBR =  CurrencyManager(
        amount: 100,
        maximum: 100,
        locale: .init(identifier: "pt_BR")
    )
    var body: some View {
        VStack(alignment: .trailing, spacing: 0) {
            Spacer()
            Group {
                Text("Locale currency")
                TextField(currencyManager.string, text: $currencyManager.string)
                    .keyboardType(.numberPad)
                    .multilineTextAlignment(.trailing)
                    .onChange(of: currencyManager.string, perform: currencyManager.valueChanged)
                Spacer()
            }
            Group {
                Text("American currency")
                TextField(currencyManagerUS.string, text: $currencyManagerUS.string)
                    .keyboardType(.numberPad)
                    .multilineTextAlignment(.trailing)
                    .onChange(of: currencyManagerUS.string, perform: currencyManagerUS.valueChanged)
                Spacer()
            }
            Group {
                Text("British currency")
                TextField(currencyManagerUK.string, text: $currencyManagerUK.string)
                    .keyboardType(.numberPad)
                    .multilineTextAlignment(.trailing)
                    .onChange(of: currencyManagerUK.string, perform: currencyManagerUK.valueChanged)
                Spacer()
            }
            Group {
                Text("French currency")
                TextField(currencyManagerFR.string, text: $currencyManagerFR.string)
                    .keyboardType(.numberPad)
                    .multilineTextAlignment(.trailing)
                    .onChange(of: currencyManagerFR.string, perform: currencyManagerFR.valueChanged)
                Spacer()
            }
            Group {
                Text("Brazilian currency")
                TextField(currencyManagerBR.string, text: $currencyManagerBR.string)
                    .keyboardType(.numberPad)
                    .multilineTextAlignment(.trailing)
                    .onChange(of: currencyManagerBR.string, perform: currencyManagerBR.valueChanged)
                
            }
            Spacer()
        }.padding(.trailing, 25)
    }
}

---

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

---

class CurrencyManager: ObservableObject {
    
    @Published var string: String = ""
    private var amount: Decimal = .zero
    private let formatter = NumberFormatter(numberStyle: .currency)
    private var maximum: Decimal = 999_999_999.99
    private var lastValue: String = ""
    
    init(amount: Decimal, maximum: Decimal = 999_999_999.99, locale: Locale = .current) {
        formatter.locale = locale
        self.string = formatter.string(for: amount) ?? "$0.00"
        self.lastValue = string
        self.amount = amount
        self.maximum = maximum
    }
    
    func valueChanged(_ value: String) {
        let newValue = (value.decimal ?? .zero) / pow(10, formatter.maximumFractionDigits)
        if newValue > maximum {
            string = lastValue
        } else {
            string = formatter.string(for: newValue) ?? "$0.00"
            lastValue = string
        }
    }
}

---

extension NumberFormatter {
    
    convenience init(numberStyle: Style, locale: Locale = .current) {
        self.init()
        self.locale = locale
        self.numberStyle = numberStyle
    }
}

---

extension Character {
    
    var isDigit: Bool { "0"..."9" ~= self }
}

---

extension LosslessStringConvertible {
    
    var string: String { .init(self) }
}

---

extension StringProtocol where Self: RangeReplaceableCollection {
    
    var digits: Self { filter (\.isDigit) }
    
    var decimal: Decimal? { Decimal(string: digits.string) }
}

---

This is the SwiftUI equivalent to the custom CurrencyField I have implemented for UIKit.

---

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