Compare date components Swift - ios

Question

I have a task where I have to read the file once a day.
1)Label with text and the date blank.
2)When the user first goes to view. I need to show the text, save it and the date when it was followed
3)Leave it all on the screen all day.
4)When the next day comes. Compare the saved date with the current date.
5)If the current date is greater than the stored date. then read the file again, show the text and the date when this is done and save
(While there is this. The text changes every time you enter the application.
A saved date = 0,)
// compare oderDate and currentDate
func showTextToDay() {
let newDatePredict = Date()
let olderDate = UserDefaults.standard.object(forKey: dateUser) as! Date // THIS PROBLEM
let order = Calendar.current.compare(olderDate, to: newDatePredict, toGranularity: .day)
switch order {
case .orderedDescending:
print("DESCENDING")
case .orderedAscending:
readFilePrediction() //read again file bcs new day
print("ASCENDING")
case .orderedSame:
print("SAME")
}
}
func readFilePrediction() {
//some code
}
// save olderDate Func
func saveDatePredictFunc() {
let oldDatePredict = Date()
UserDefaults.standard.set(oldDatePredict, forKey: dateUser)
let dateLabel = UserDefaults.standard.object(forKey: dateUser) as! Date
let df = DateFormatter()
df.dateFormat = "dd/MM/yyyy"
toDateOutlet.text = df.string(from: dateLabel)
defaults.set(toDateOutlet.text, forKey: dateUser)
}

Answer 1

You have to check also if a date a available at all.
The guard statement represents a NOR expression. readFilePrediction will be executed if the date does NOT exist OR the date comparison is ascending.
func showTextToDay()
{
guard let olderDate = UserDefaults.standard.object(forKey: dateUser) as? Date,
Calendar.current.compare(olderDate, to: Date(), toGranularity: .day) != .orderedAscending else {
readFilePrediction()
saveDatePredictFunc()
return
}
}
And reading the data right after saving it to UserDefaults (dateLabel) is very bad practice. You got the value. And delete also the line to save the string representation of the date. The line breaks the ability to read the value as Date.
func saveDatePredictFunc()
{
let oldDatePredict = Date()
UserDefaults.standard.set(oldDatePredict, forKey: dateUser)
let df = DateFormatter()
df.dateFormat = "dd/MM/yyyy"
toDateOutlet.text = df.string(from: oldDatePredict)
}