Checking the contents of a TextField variable method not working

Question

Created May ’25

Replies 26

Boosts 0

Participants 3

Hoping someone can help me with this… The error is… Generic parameter ‘/‘ cannot be inferred.

                            .multilineTextAlignment(.center)
                            .onAppear(perform: {
                                var checkFirstCardLatitude = cards.firstCardLatitude
                                let charArray = Array(checkFirstCardLatitude)
                                let allowed: [Character] = ["-", ".", "0", "1", "2", "3", "4", "5", "6", "7", "8", "9"]
                                for char in charArray {
                                    if char != allowed {
                                        cards.firstCardLatitude = "000.000000" // Reset Text Field
                                    }
                                }
                            })

Answered by darkpaw in 838112022

There is a slight issue with the regex, in that it seems to be allowing you to enter something like -12..sssds. It seems that as soon as you enter the second full-stop you can enter anything, so you may want to either check the regex, or work around it with some more code in the Coordinate.validate() function.

Answer 1 · May 19, 2025 07:39 PM

GMacD53 OP

May ’25

Thanks again for your help with this. Although I have not used your solution exactly it did help me a great deal to construct a solution (example enclosed).

Still working on these examples of input error…

-.234567 (If (Left of “.”) contains “-“ then the length of (Left of “.” ) minimum = 2).

1-2.123456 (If (Left of “.”) contains “-“ it should be the first character.

I understand your solution is far better because it reduces the amount of code etc. but I am not ready to rebuild my app from the ground-up yet. I need to learn and understand Swift alot more before I tackle that.

// In this example “coordinate” is either Latitude or Longitude
// Error example = 00.000000

// If coordinate contains more than one  “-“ 
if(coordinate.filter( { $0 == "-" } ).count > 1) {
            coordinate = "00.000000" // Reset coordinate
            }

// If coordinate contains more than one  “.“
if(coordinate.filter( { $0 == "." } ).count != 1) {
                coordinate = "00.000000" // Reset coordinate
            }

// If coordinate contains an illegal character
// Get coordinate length before check
let coordinateLengthBefore = coordinate.count 
let validCharsCoordinate: Set<Character> = ["-", ".", "0", "1", "2", "3", "4", "5", "6", "7", "8", "9"] // Allowed characters
// Remove characters not in Character Set
coordinate.removeAll(where: { !validCharsCoordinate.contains($0) } )
// Get coordinate length after check
let coordinateLengthAfter = coordinate.count
// If coordinate length is different due to illegal character removal
        if coordinateLengthBefore != coordinateLengthAfter {
                coordinate = "00.000000" // Reset coordinate
            }

// Check each side of the "."
// Check coordinate before the "."
        let coordinateStr = coordinate
        let coordinateCh = Character(".")
        let coordinateResult = coordinateStr.split(separator: coordinateCh).map         { String($0) }
        let coordinateLeftSplit = coordinateResult[0]
        let coordinateLeftCount = coordinateLeftSplit.count
        if coordinateLeftCount >= 4 { // More than 3 characters before "."
cards.firstCardLatitude = "00.000000" // Reset coordinate
            }
// Check coordinate after the "."
        let coordinateRightSplit = coordinateResult[1]
if(coordinateRightSplit.filter( { $0 == "-" } ).count > 0) {
                coordinate = "00.000000" // Reset coordinate ("-" not allowed)
            }