How to format a textfield so when user inputs data its in format similar to 80/150?

Question

Currently there is a textfield that after a user enters data it has to post to a server in a format similar to 60/500, so basically a fraction. I'm familiar with setting up a textfield and connecting it via storyboard along with setting up text input traits so the number pad will show up. I'm just not sure how to change the entered textfield into the '30/90' fraction format and posting it. Any help will be greatly appreciated!

Answer 1

You could do it this way, after setting self as the delegate:

let slash = "/"
let digits = CharacterSet(charactersIn: "0123456789")

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

    //Deleting
    if string.count == 0 {
        var text = textField.text!
        let start = text.startIndex
        let beginRange = text.index(start, offsetBy: range.location)
        let endRange = text.index(start, offsetBy: range.location + range.length)
        text = String(text.prefix(upTo: beginRange))
            + String(text.suffix(from: endRange))
        text = text.replacingOccurrences(of: "/", with: "")
        if text.count >= 3 {
            text = String(text.prefix(2)) + "/" + String(text.dropFirst(2))
        }

        textField.text = text

        return false
    }

    //Typing

    let count = textField.text!.count
    guard string.count == 1,
        count < 6,
        let scalar = Character(string).unicodeScalars.first else {
            return false
    }

    let isDigit = digits.contains(scalar)

    switch count {
    case 0, 3..<6 :
        return isDigit
    case 1:
        if isDigit {
            textField.text = textField.text! + string + "/"
        }
        return false
    case 2:
        if string == slash {
            return true
        } else {
            textField.text = textField.text! + "/" + string
            return false
        }
    default:
        return false
    }
}

This code works with the default keyboard too, and not just the numeric pad.