How to get te text of a textfield from inside a function?

Question

I want to make an app that has 2 textfields, 4 buttons and a Text view. 1 button that clears the content of the first textfield and another button that inputs the current time rounded to the nearest 4 and the Text view to display the total time in minutes. Same with the other textfield. It's an app to calculate the total time spent on something in minutes.

I also want to limit the amount of possible insertable characters to 5 as a time has a maximum of 5 characters as in "15:00". I have been able to make an observable object:

class TextFieldManager: ObservableObject {

    let characterLimit = 5

    @Published var userInput = "" {
        didSet {
            // Limit the max length of the field
            if userInput.count > characterLimit {
                userInput = String(userInput.prefix(characterLimit))
            } else if userInput.count >= 4 {
                // call the setTotalTime func or something to set totalTime
            }
        }
    }
}

which works really well.

I am also able to clear the textfield and set the current time rounded to the nearest 5, but i am unable to limit the characters to 5 AND have the buttons do something at the same time.

So right now it's either being able to: - Limit characters to a maximum of 5

OR being able to:

• clear textfield with a button
• input time now rounded to nearest 5 into textfield with a button.

If i go with the observable object method, when i have this above the body block of my ContentView:

@ObservedObject var startTimeManager = TextFieldManager()
@ObservedObject var endTimeManager = TextFieldManager()

and this inside the body for the textfields:

TextField("hh:mm", text: $startTimeManager.userInput)
TextField("hh:mm", text: $endTimeManager.userInput)

and the TextFieldManager class as shown above, than now i don't know how to get the value of the Textfield anymore.

If inside the input the current time button i try to set the time by doing

$startTimeManager.userInput = "whatever the current time is"

i get an error saying that i can't change the value of a binding<String> type something something. Likewise i also can't clear the textfield in the same way.

Also i would like to call a function inside this part:

} else if userInput.count >= characterLimit {
    // call the setTotalTime func or something to set totalTime
}

I have a Functions.swift file where both the TextFieldManager class is and my function that i want to call, but if i try to call a function inside here, it says that the function doesn't exist? And inside the function i again would like to have access to the textfield values at the time of the call, but i don't know how to read the value of the textfields from inside the function.

I hope i am making sense and that someone is able to help me, or point me in the right direction. I made the same app for android (android studio), windows (python3) and Mac (python3), but this iphone and Xcode thing really doesn't want to work. I have watched a bunch of tutorial videos and guides, but none are trying to do what i am trying to do. Like i said i can get either to work, but never together and in both cases i am unable to somehow access the textfield values inside the function. I feel like i should be so close, but something is not coming together for me in my head.

Also while i'm at it, in Python 3 to catch all errors and let them pass silently i can do:

Try:
    break_my_stuff = int("Break my stuff)"
    ignore_some_more_stuff = int("ignore some more stuff)"
    etc.
    etc.
except Exception:
    # catch silently and do nothing
    pass

Is there something similar in swift, because

do {
    breakMyStuff = whatever might make something break in swift
    ignoreSomeMoreStuff = whatever might make something break in swift
    etc.
    etc.
} catch {
    // do nothing and pass silently
}

doesn't work because it needs something to try and i wasn't able to try a complete section like i can with Python.

Answer 1

If inside the input the current time button i try to set the time by doing

$startTimeManager.userInput = "whatever the current time is"

you don't need binding in this case, just assign property in regular way

self.startTimeManager.userInput = "whatever the current time is"