SwiftUI Views with a custom init

Question

Let's say that I am making a custom input element that looks like this:

struct CustomInput : View {
    @Binding var text: String
    var name: String

    var body: some View {
        TextField(name, text: $text)
            .modifier(InputModifier())

    }
}

Currently, when I instantiate this view I'm required to pass both text and name names to arguments. I want to be able to make the name argument optional, like in the example below.

 CustomInput("Some name", $text)

Typically I'd use an init method for this. But I'm not sure how to handle property wrappers like @Binding in the init function.

Any ideas on how I can achieve this?

kontiki · Accepted Answer · 2019-07-18 05:12:32Z

86

You can write your initializer like this:

struct CustomInput : View {
    @Binding var text: String
    var name: String

    init(_ name: String, _ text: Binding<String>) {
        self.name = name

        // Beta 3
        // self.$text = text

        // Beta 4
        self._text = text
    }

    var body: some View {
        TextField(name, text: $text)
    }
}

edited Jul 18, 2019 at 5:12

answered Jul 6, 2019 at 4:41

kontiki

41k13 gold badges121 silver badges129 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

kontiki Over a year ago

Property wrappers changed in beta 4, code updated to reflect that.

kontiki Over a year ago

@matt: The $ accesor is now non mutable. When initialising it that way with beta4, the compiler will give you: Cannot assign to property: '$text' is immutable. Note that the dollar sign is still used for passing a binding, the underscore is only necessary when initialising it.

matt Over a year ago

Yes, I figured it out. You haven’t quite described correctly what they did but I am really glad you alerted me to this change! Thanks very much. Here is a summary of the change: forums.swift.org/t/se-0258-property-wrappers-third-review/26399

Collectives™ on Stack Overflow

SwiftUI Views with a custom init

1 Answer 1

3 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related