UITextField format in xx-xx-xxx

Question

I am using UITextField and i want that should take character in the format of xx-xx-xxx only numbers.

any help ?

Answer 1

My solution works like that:

Implement in your textfield delegates:

func textFieldDidBeginEditing(_ textField: UITextField) {
        // When you start editing check if there is nothing, in that case add the entire mask
        if let text = textField.text, text == "" || text == "DD/MM/YYYY" {
            textField.text = "DD/MM/YYYY"
            textField.textColor = .lightGray
            textField.setCursor(position: text.count)
        }
    }

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

    guard var number = textField.text else {
        return true
    }
    // If user try to delete, remove the char manually
    if string == "" {
        number.remove(at: number.index(number.startIndex, offsetBy: range.location))
    }
    // Remove all mask characters
    number = number.replacingOccurrences(of: "/", with: "")
    number = number.replacingOccurrences(of: "D", with: "")
    number = number.replacingOccurrences(of: "M", with: "")
    number = number.replacingOccurrences(of: "Y", with: "")

    // Set the position of the cursor
    var cursorPosition = number.count+1
    if string == "" {
        //if it's delete, just take the position given by the delegate
        cursorPosition = range.location
    } else {
        // If not, take into account the slash
        if cursorPosition > 2 && cursorPosition < 5 {
            cursorPosition += 1
        } else if cursorPosition > 4 {
            cursorPosition += 2
        }
    }
    // Stop editing if we have rich the max numbers
    if number.count == 8 { return false }
    // Readd all mask char
    number += string
    while number.count < 8 {
        if number.count < 2 {
            number += "D"
        } else if number.count < 4 {
            number += "M"
        } else {
            number += "Y"
        }
    }
    number.insert("/", at: number.index(number.startIndex, offsetBy: 4))
    number.insert("/", at: number.index(number.startIndex, offsetBy: 2))

    // Some styling
    let enteredTextAttribute = [NSForegroundColorAttributeName: UIColor.black, NSFontAttributeName: UIFont.systemFont(ofSize: 15)]
    let maskTextAttribute = [NSForegroundColorAttributeName: UIColor.lightGray, NSFontAttributeName: UIFont.systemFont(ofSize: 15)]

    let partOne = NSMutableAttributedString(string: String(number.prefix(cursorPosition)), attributes: enteredTextAttribute)
    let partTwo = NSMutableAttributedString(string: String(number.suffix(number.count-cursorPosition)), attributes: maskTextAttribute)

    let combination = NSMutableAttributedString()

    combination.append(partOne)
    combination.append(partTwo)

    textField.attributedText = combination
    textField.setCursor(position: cursorPosition)


    return false
}

func textFieldDidEndEditing(_ textField: UITextField) {
    if let text = textField.text, text != "" && text != "DD/MM/YYYY" {
        // Do something with your value
    } else {
        textField.text = ""
    }
}

And that little helper as an extension:

extension UITextField {
    func setCursor(position: Int) {
        let position = self.position(from: beginningOfDocument, offset: position)!
        selectedTextRange = textRange(from: position, to: position)
    }
}

PS: there is still a bug in that implementation when you try to move the cursor while editing