CODEWITHSUNDEEP
swiftdate
DanCode
DanCode

Reputation: 673

Swift 4: validating credit card expiration date

I am writing code to check whether the credit card has expired or not.

Here is what I have

let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "MM/yyyy"
let enteredDate = dateFormatter.date(from: expiryDate.text!) /* line 3 - set to first day of month */
let now = Date()
if (enteredDate! < now) {
    //expired
    // does not work if current month and year 
    // is the same as the expiration date, 
    // because expiration day is set to the first day of the month on line 3
} else {
    // valid
    print("valid - now: \(now) entered: \(enteredDate)")
}

Any ideas on how I can change the initialized date to be the last day of the month instead of the first day?

Upvotes: 0

Views: 6073

Answers (6)

hari sri
hari sri

Reputation: 11

Here is the full answer for Expiry date calculation from textfield formatted as MM/YY. Use this in textfieldshouldchangecharactersinrange method

var cleanString = string.replacingOccurrences(of: "/", with: "")
    
    if cleanString.rangeOfCharacter(from: unsupportedCharacterSet) != nil {
        return ""
    }
    
    let dateString: String
    
    if cleanString.count == 0 {
        return string
    } else if cleanString.count > 4 {
        // trim the string down to 4
        
        let reqIndex = cleanString.index(cleanString.startIndex, offsetBy: 4)
        cleanString = String(cleanString[..<reqIndex])
        
    }
    
    if cleanString.hasPrefix("0") == false && cleanString.hasPrefix("1") == false {
        dateString = "0" + cleanString
    } else {
        dateString = cleanString
    }
    let currentYear = Calendar.current.component(.year, from: Date()) % 100   // This will give you current year (i.e. if 2019 then it will be 19)
      let currentMonth = Calendar.current.component(.month, from: Date()) // This will give you current month (i.e if June then it will be 6)
    var newText = ""
    for (index, character) in dateString.enumerated() {
        print("index: \(index)")
        if index == 1 {
            let enterdMonth = Int(dateString.prefix(2)) ?? 0  // get first two digit from entered string as month
            print("enterdMonth at 1:\(enterdMonth)")
            if (1 ... 12).contains(enterdMonth){
                if enterdMonth < 10 {
                    newText = "0" + "\(enterdMonth)" + "/"
                }else {
                    newText = "\(enterdMonth)" + "/"
                }
            }else{
                
            }
        }else if index == 2 {
            if (2 ... 99).contains(Int(String(character))!) { // Entered year should be greater than 2019.
                newText.append(character)
            }else{
                
            }
        }else if index == 3 {
            print("index---: \(index)")
            let enterdYr = Int(dateString.suffix(2)) ?? 0   // get last two digit from entered string as year
            let enterdMonth = Int(dateString.prefix(2)) ?? 0  // get first two digit from entered string as month
            print("enterdYr: \(enterdYr)")
            print("currentYear: \(currentYear)")
            if (2 ... 99).contains(enterdYr) { // Entered year should be greater than 2019
                if enterdYr >= currentYear {
                    if (1 ... 12).contains(enterdMonth) {
                        if enterdMonth < 10 {
                            newText = "0" + "\(enterdMonth)" + "/" + "\(enterdYr)"
                        }else {
                            newText = "\(enterdMonth)" + "/" + "\(enterdYr)"
                        }
                        return newText
                    }
                }
            }
        }
        else {
            newText.append(character)
        }
    }
    return newText
}

Upvotes: 0

RajeshKumar R
RajeshKumar R

Reputation: 15758

Instead of comparing the dates, compare month of the dates using compare(_:to:toGranularity:)

let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "MM/yyyy"
if let enteredDate = dateFormatter.date(from: "05/2019") {
    let result = Calendar.current.compare(Date(), to: enteredDate, toGranularity: .month)
    if result == .orderedSame {
        print("valid")
    } else if result == .orderedAscending {
        print("valid")
    } else if result == .orderedDescending {
        print("expired")
    }
}

Upvotes: 1

Najeeb ur Rehman
Najeeb ur Rehman

Reputation: 413

let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "MM/yyyy"
let enteredDate = dateFormatter.date(from: expiryDate.text!)

//Also convert the current date in the entered date format and then checks that the date is valid if enteredDate month or year is greater than current date. 
let currentDate = dateFormatter.date(from: dateFormatter.string(from: Date()))

if enteredDate.compare(now) != ComparisonResult.orderedAscending {
    print("Valid")   
} else {
    print("Not Valid")
}

As this only compares the month and year so it will resolve your issue of first or last date of month.

Upvotes: 0

rmaddy
rmaddy

Reputation: 318824

enteredDate will be midnight local time on the first of the month of the expiry date. Since you want that whole month to be valid, add 1 month to that value and then compare Date() to that updated value.

let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "MM/yyyy"
let enteredDate = dateFormatter.date(from: expiryDate.text!)!
let endOfMonth = Calendar.current.date(byAdding: .month, value: 1, to: enteredDate)!
let now = Date()
if (endOfMonth < now) {
    print("Expired - \(enteredDate) - \(endOfMonth)")
} else {
    // valid
    print("valid - now: \(now) entered: \(enteredDate)")
}

Please note that I left proper handling of optionals as an exercise for the reader.

Upvotes: 6

Nina
Nina

Reputation: 1679

rmaddy's answer is perfect. Here is how I thought of using Calendar to handle the validation. Perhaps, I wrote it in more complex way.

enum ExpiryValidation {
    case valid, invalidInput, expired
}

func validateCreditCardExpiry(_ input: String) -> ExpiryValidation {

    let dateFormatter = DateFormatter()
    dateFormatter.dateFormat = "MM/yyyy"

    guard let enteredDate = dateFormatter.date(from: input) else {
        return .invalidInput
    }
    let calendar = Calendar.current
    let components = Set([Calendar.Component.month, Calendar.Component.year])
    let currentDateComponents = calendar.dateComponents(components, from: Date())
    let enteredDateComponents = calendar.dateComponents(components, from: enteredDate)

    guard let eMonth = enteredDateComponents.month, let eYear = enteredDateComponents.year, let cMonth = currentDateComponents.month, let cYear = currentDateComponents.year, eMonth >= cMonth, eYear >= cYear else {
        return .expired
    }
    return .valid
}

let invalidInput = validateCreditCardExpiry("hello")
let validInput = validateCreditCardExpiry("09/2020")
let expiredInput = validateCreditCardExpiry("04/2010")

Upvotes: 0

KAREEM MAHAMMED
KAREEM MAHAMMED

Reputation: 1695

if enteredDate.compare(now) == ComparisonResult.orderedDescending
        {
            print("valid")
        }
else{
      print("not valid")
}

Upvotes: -2

Related Questions