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swiftuianyobjectviewmodifier

how do I make a swiftui viewmodifier that accepts any object?


I have a quite few reusable viewmodifiers in my projects, but I have never been able to make one that accepts any object instead of a specific object.

Fx. in below viewmodifier, how would I make it accept any object instead of just "StopContent" so I didn't have to write a new viewModifier each time I wanted to use it on a new object?

struct DragToDeleteContent: ViewModifier {
    
    let stopContent:StopContent
    @Binding var contentArray: [StopContent]
    @State private var deleted:Bool = false
    
    func body(content: Content) -> some View {
        return content
            .dragToDelete(deleted: $deleted)
            .onChange(of: deleted, perform: { deleted in
                if deleted { delete() }
            })
    }
    
    func delete() {
        if let arrayIndex = contentArray.firstIndex(of: stopContent) {
            contentArray.remove(at: arrayIndex)
        }
    }
}

Solution

  • Every model confirms with Identifiable protocol so you can make it generic by Identifiable.

    here is the possible solution

    struct DragToDeleteContent<T: Identifiable>: ViewModifier {
        
        let stopContent: T
        @Binding var contentArray: [T]
        @State private var deleted:Bool = false
        
        func body(content: Content) -> some View {
            return content
                .dragToDelete(deleted: $deleted)
                .onChange(of: deleted, perform: { deleted in
                    if deleted { delete() }
                })
        }
        
        func delete() {
            if let arrayIndex = contentArray.firstIndex(where: {$0.id == stopContent.id}) {
                contentArray.remove(at: arrayIndex)
            }
        }
    }
    

    Data Model

    struct TestModel: Identifiable {
        var id = UUID()
        var name: String
    }
    

    Usage

    }.modifier(DragToDeleteContent(stopContent: TestModel(name: "Abc"), contentArray: .constant([.init(name: "Xyz"), .init(name: "opq")]))) // I used .constant for the demo purpose. Bind you Identifiable array here.