Manual formatting - ios

Question

Newbie in Swift, please help me out, when I type . or after .0 or .00 it should reflect with 0.00, but this is not visible to myTxtField.text.
Following is my code -
func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
// return NO to not change text
//Decimal
switch string {
case "0","1","2","3","4","5","6","7","8","9",".":
currentString += string
print(currentString)
formatCurrency(currentString)
default:
if string.characters.count == 0 && currentString.characters.count != 0 {
currentString = String(currentString.characters.dropLast())
formatCurrency(currentString)
}
}
return false
}
func formatCurrency(string: String) {
let formatter = NSNumberFormatter()
formatter.numberStyle = NSNumberFormatterStyle.DecimalStyle
formatter.maximumFractionDigits = 2
formatter.roundingMode = .RoundDown
formatter.locale = NSLocale(localeIdentifier: "en_US")
let numberFromField = (NSString(string: currentString).doubleValue)
let tAmount:String!
if string == "" {
myTxtField.text = ""
tAmount = "$" + formatter.stringFromNumber(numberFromField)!
}else {
myTxtField.text = "$" + formatter.stringFromNumber(numberFromField)!
tAmount = "$" + formatter.stringFromNumber(numberFromField)!
}
print("value=\(HManager.convertCurrencyToDouble(tAmount))")
}

Answer 1

The following is an example of using shouldChangeCharactersIn delegate method and editingDidEnd to achieve your goal.
The shouldChangeCharactersIn to limit the text field to accepting only number and decimal point ..
The editingDidEnd is to format the text field with 2 decimal digits.
import UIKit
class ViewController: UIViewController, UITextFieldDelegate {
#IBOutlet weak var textField: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
textField.delegate = self
}
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
let allowedCharacters = CharacterSet.decimalDigits
if string.rangeOfCharacter(from: allowedCharacters.inverted) != nil {
// If the added character is not a number
if string == "." {
// If the added character is the decimal point
let countDots = textField.text!.components(separatedBy: ".").count - 1
if countDots == 0 {
return true
}
}
return false
}
return true
}
#IBAction func editingDidEnd(_ sender: UITextField) {
// Format the input with 2 decimal digits.
if let input = sender.text, let inputDouble = Double(input) {
sender.text = String(format: "%.2f", inputDouble)
} else {
sender.text = "0.00"
}
}
}
UPDATE
In order to add a currency symbol ($) and remove the fractional part if needed, you need to have a function to check whether the input is double or Int.
#IBAction func editingDidEnd(_ sender: UITextField) {
// Format the input with 2 decimal digits.
if let input = sender.text, let number = Double(input) {
if canConvertToInt(number) {
sender.text = "$\(Int(number))"
} else {
sender.text = "$\(number)"
}
} else {
sender.text = "$0"
}
}
// Check if the number is not decimal
func canConvertToInt(_ double: Double) -> Bool {
return rint(double) == double
}