I am working on an app that has a startTime, endTime and duration. The user can set the endTime by click a button and it sets the value to "now" in the format 12:02:03 PM. I then want to be able to enter a duration time in minutes, let's say 20 minutes.
I have everything working where I can read the duration in real time as well as see the current time. The issue is when I try to create a function to subtract the duration from the endTime. I cannot seem to get the syntax or the formatting correct.
I've done quite a bit of searching for examples of this. Here is what I came across so far.
How to add minutes to current time in swift
How to subtract date components?
How to get the current time as datetime
func controlTextDidChange(_ obj: Notification) {
let enteredValue = obj.object as! NSTextField
timeString(time: enteredValue.doubleValue)
}
func timeString(time: TimeInterval) {
formatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
let myString = formatter.string(from: Date())
let yourDate = formatter.date(from: myString)
formatter.dateFormat = "hh:mm:ss a"
yourDate!.addingTimeInterval(0-time)
let wtf = formatter.string(from: yourDate!)
startTime.stringValue = wtf
}
The controlTextDidChange function is watching the durationTextField and I am able to print to console the input. I then want to be able to run the timeString function with the durationTextField value and subtract it from the endTime and then set that value to startTime.
One thing that is weird is Xcode tells me:
Result of call to 'addingTimeInterval' is unused
You are taking too many steps. Just create a Date that is time seconds from "now". Then convert that Date to a String.
func timeString(time: TimeInterval) {
let startDate = Date(timeIntervalSinceNow: -time)
formatter.dateFormat = "hh:mm:ss a"
let wtf = formatter.string(from: startDate)
startTime.stringValue = wtf
}
I'm assuming you want startDate to be time seconds before now.