SwiftUI Form Validation

Main Idea

SwiftUI’s Form view lets us store user input in a really fast and convenient way, but sometimes it’s important to go a step further – to check that input to make sure it’s valid before we proceed.

Well, we have a modifier just for that purpose: disabled(). This takes a condition to check, and if the condition is true then whatever it’s attached to won’t respond to user input – buttons can’t be tapped, sliders can’t be dragged, and so on. You can use simple properties here, but any condition will do: reading a computed property, calling a method, and so on,

struct ContentView: View {
    @State private var username = ""
    @State private var email = ""
    
    var disableForm: Bool {
        username.count < 5 || email.count < 5
    }
    
    var body: some View {
        Form {
            Section {
                TextField("Username", text: $username)
                TextField("Email", text: $email)
            }
            
            Section {
                Button("Create account") {
                    print("Creating account...")
                }
            }
            .disabled(disableForm)
        }
    }
}

Notes mentioning this note

SwiftUI Form
Main Idea Forms are scrolling lists of static controls like text and images, but can also include user interactive controls...

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