How to show alert message in swiftUI when user enters time below the expected time?

Question

I'm building an alarm kinda app and I just want to display a pop up message (alert message) when user enter time below 2 hours, the user should get a message by saying like, "please enter time more than 2 hours of duration".

This is where I stored the alarm value

myViewModel.myModel.waketime

and I want to display the message when a user click this below image

 Image(systemName: "checkmark.circle")
                        .resizable()
                        .aspectRatio(contentMode: .fit)
                        .clipShape(Circle())
                        .sheet(isPresented: $showPlayer) {
                            SecondView()
                        }

This is another view where the user picks the alarm time

 Text("Alarm : ")
  .font(.body)
   Spacer()
   DatePicker("", selection: self.$myViewModel.myModel.waketime, displayedComponents: .hourAndMinute)

Please help me to solve this!!

jnpdx · Accepted Answer · 2021-03-10T06:44:18.903

You can use Alert to show an alert to the user. In order to do this when the user clicks on the Image, you'd probably want to wrap it in a Button:

struct ContentView : View {
    @State var alertShown = false
    
    var body: some View {
        Button(action: {
            if true { //here, you can check your condition for whether the alert should get triggered -- like checking `myViewModel.myModel.waketime > x`
                alertShown = true
            }
        }) {
            Image(systemName: "checkmark.circle")
                .resizable()
                .aspectRatio(contentMode: .fit)
                .clipShape(Circle())
        }.alert(isPresented: $alertShown) {
            Alert(title: Text("Please enter time more than 2 hours of duration"))
        }
    }
}

You may want to add .buttonStyle(PlainButtonStyle()) as a modifier to the Button if you don't want it to change your Image to the accentColor in your project.

Update in response to comments: The general check you'd want to do is:

if myViewModel.myModel.waketime.timeIntervalSince1970 - Date().timeIntervalSince1970 < 60 * 60 * 2 {

However, be aware that with your current strategy of only showing hours and minutes, this will start to fail at 2 hours before midnight, since the DatePicker will default to the current date, making 1 AM, for example, register as before the current date/time, not after. So, you'll want to add some additional logic to account for things like that. For example, you could add 24 hours to any time before the current date.

but how will it check with my time? it should retrieve time from "myViewModel.myModel.waketime" and check whether the time is less than or more than 2 hrs. example (if the user sets time at 2:00pm and now the time is 1:00pm, it should give a message and indicate user to enter time duration more than 2hrs) — sesaxe7169, Mar 10 '21 at 06:31
Look at the code that I gave -- there's a comment telling you exactly where to do that check. You didn't give any details about what format/time `waketime` is in, so I can't give you the exact code unless you give more details. — jnpdx, Mar 10 '21 at 06:33
thank you for the reply. could you please check my edited question? — sesaxe7169, Mar 10 '21 at 06:37

How to show alert message in swiftUI when user enters time below the expected time?

1 Answers1