Creating and writing multiple lines of text to a text file (CSV)? - swift

Question

I'm trying to create a way for a user to sign in and store their username and password in a text file. This is for a school project, so it's not stored securely and I don't think I'll have time to set up/learn how to serialize the data anyways.
The main part I'm having issues with is trying to write the data as a CSV to later split the user's scores into an array based off of the data it received from the text file.
I've tried a different method of writing to the text file which was:
writeString.data(using: String.Encoding.utf8)?.write(to: fileURL, options: Data.WritingOptions.withoutOverwriting) But this didn't seem to work for me
struct UserAccount: Codable {
var username: String
var password: String
var scores: [Int]
}
var user = UserAccount(username: "", password: "", scores: [0])
func writeTextFile(_ user: UserAccount) {
//Creating text file to read and write user's data (username, password, and score values)
let fileName = "UserDataQuizApp"
let dir = try? FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
do {
let fileManager = FileManager.default
if fileManager.fileExists(atPath: "UserDataQuizApp") {
try fileManager.removeItem(atPath: fileName)
}
} catch {print("error when deleting \(fileName)") }
// If the directory was found, we write a file to it and read it back
if let fileURL = dir?.appendingPathComponent(fileName).appendingPathExtension("txt") {
print("The path is: \(fileURL)")
do {
try user.username.write(to: fileURL, atomically: false, encoding: .utf8)
try ",".write(to: fileURL, atomically: false, encoding: .utf8)
try user.password.write(to: fileURL, atomically: false, encoding: .utf8)
for i in 0 ... user.scores.count {
try ",".write(to: fileURL, atomically: true, encoding: .utf8)
try String(user.scores[i]).write(to: fileURL, atomically: true, encoding: .utf8)
}
} catch {
print("Failed writing to URL: \(fileURL), Error: " + error.localizedDescription)
}
}
}
Writing the array to the text file doesn't work at all right now because it says the index is out of range, but when I commented it out and tried to only write the username and password, only the password would be in the file when I checked it. I was expecting the username, a comma, and then the password to be in it

Answer 1

Reason for crash is in line for i in 0 ... user.scores.count it should be either for i in 0 ..< user.scores.count or for score in user.scores.
And you are trying to write each text to a file.
That means only last write(to:.. will have effect. Everything written will be overwritten.
To fix that, create a single string contains all info then write it to the file.
For eg the write function should be like :
func writeTextFile(_ user: UserAccount) {
//Creating text file to read and write user's data (username, password, and score values)
let fileName = "UserDataQuizApp"
let dir = try? FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
do {
let fileManager = FileManager.default
if fileManager.fileExists(atPath: "UserDataQuizApp") {
try fileManager.removeItem(atPath: fileName)
}
} catch {print("error when deleting \(fileName)") }
// If the directory was found, we write a file to it and read it back
if let fileURL = dir?.appendingPathComponent(fileName).appendingPathExtension("txt") {
print("The path is: \(fileURL)")
do {
var contents = [user.username, user.password]
contents.append(contentsOf: user.scores.map { "\($0)"})
let string = contents.joined(separator: ",")
print("contents \(string)")
try string.write(to: fileURL, atomically: false, encoding: .utf8)
} catch {
print("Failed writing to URL: \(fileURL), Error: " + error.localizedDescription)
}
}
}