How to pass type Namespace.ID in preview parameter in SwiftUI?

Question

I am creating a subview in SwiftUI with few parameters. One of the parameters' type is Namspace.ID. So I have to pass the Namespace.ID type parameter through preview to see the view in Xcode canvas. I don't know how to do it. My codes look like this.

    struct BagView: View {
        var bagData:BagModel
        var animation:Namespace.ID
        var body: some View {
            VStack{
                ZStack{
                    Color(bagData.image)
                        .cornerRadius(15)
                    Image(bagData.image)
                        .resizable()
                        .aspectRatio(contentMode: .fit)
                        .padding(20)
                        .matchedGeometryEffect(id: bagData.image, in: animation)
                }
                Text(bagData.title)
                    .fontWeight(.heavy)
                    .foregroundColor(.gray)
                Text(bagData.price)
                    .fontWeight(.heavy)
                    .foregroundColor(.black)
            }
        }
    }
    
    struct BagView_Previews: PreviewProvider {
        static var previews: some View {
            BagView(bagData: BagModel(image: "bag1", title: "The Bag", price: "$123")) 
// I am getting an error here: Missing argument for parameter 'animation' in call
        }
    }

How can I see the view in Canvas by resolving the error?

Zelko · Accepted Answer · 2022-05-31 05:43:06Z

16

The error tells you, that you forgot a parameter, since animation is a required and non-optional field. So you need to add a value for the property "animation". Something like that:

BagView(bagData: BagModel(...), animation: <valueHere>)

EDIT: You should be able to inject a Namespace value doing the following:

struct BagView_Previews: PreviewProvider {
    @Namespace static var namespace // <- This

    static var previews: some View {
        BagView(bagData: BagModel(image: "bag1", title: "The Bag", price: "$123"), animation: namespace) 
    }
}

edited May 31, 2022 at 5:43

Zelko

3,9913 gold badges37 silver badges42 bronze badges

answered Jan 28, 2021 at 9:38

fusion

4575 silver badges15 bronze badges

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

3 Comments

Tanvirgeek Over a year ago

I know that, Thats what I am asking what to give as a parameter there.

fusion Over a year ago

yikes my fault, didn't read your question carefully. look at my edit

lmunck Over a year ago

This is actually the more elegant solution. Too bad it takes a second read to get there :)

Gagan_iOS · Accepted Answer · 2023-07-03 21:39:29Z

10

Late Answer but I found one more option below (I came here on SO to search for Namespace)

add Namespace().wrappedValue

example: -

struct TabItemView_Previews: PreviewProvider {
    static var previews: some View {
        TabItemView(tintColor: .blue, inActiveColor: .gray, tab: .home, tabAnimation: Namespace().wrappedValue, activeTab: .constant(.home))
    }
}

edited Jul 3, 2023 at 21:39

answered Jul 3, 2023 at 21:29

Gagan_iOS

4,2123 gold badges37 silver badges59 bronze badges

Comments

Asperi · Accepted Answer · 2021-01-28 09:53:09Z

9

Here is possible approach - use intermediate test/preview view:

struct BagView_Previews: PreviewProvider {
    struct TestView: View {
        @Namespace var ns
        var body: some View {
            BagView(bagData: BagModel(image: "bag1", title: "The Bag", price: "$123"), 
                    animation: ns)
        }
    }
    static var previews: some View {
        TestView()
    }
}

answered Jan 28, 2021 at 9:53

Asperi

262k28 gold badges594 silver badges889 bronze badges

2 Comments

Tanvirgeek Over a year ago

Yes it is working, Can you please explain a little, what's happening? Thank You.

Asperi Over a year ago

We just create preview-only wrapper view that provides all needed parameters to actually target view.

Collectives™ on Stack Overflow

How to pass type Namespace.ID in preview parameter in SwiftUI?

3 Answers 3

3 Comments

Comments

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

3 Comments

Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related