How do I add pull-to-refresh to lists in Combine with Swift?

Implementing pull-to-refresh in SwiftUI lists with Combine allows for a seamless user experience when fetching new data. Below is an example of how to achieve this functionality using Swift.


        import SwiftUI
        import Combine

        struct ContentView: View {
            @State private var items: [String] = []
            @State private var isRefreshing = false
            private var cancellable: AnyCancellable?

            var body: some View {
                List {
                    ForEach(items, id: \.self) { item in
                        Text(item)
                    }
                }
                .pullToRefresh(isShowing: $isRefreshing) {
                    fetchData()
                }
                .onAppear {
                    fetchData()
                }
            }

            private func fetchData() {
                isRefreshing = true
                cancellable = Just([1, 2, 3, 4, 5].map { "Item \($0)" })
                    .delay(for: .seconds(2), scheduler: RunLoop.main)
                    .sink(receiveCompletion: { _ in
                        isRefreshing = false
                    }, receiveValue: { newItems in
                        items = newItems
                    })
            }
        }

        extension View {
            func pullToRefresh(isShowing: Binding, action: @escaping () -> Void) -> some View {
                self.modifier(PullToRefresh(isShowing: isShowing, action: action))
            }
        }

        struct PullToRefresh: ViewModifier {
            @Binding var isShowing: Bool
            let action: () -> Void

            func body(content: Content) -> some View {
                content
                    .background(GeometryReader { geometry in
                        Color.clear.preference(key: ScrollOffsetKey.self, value: geometry.frame(in: .global).minY)
                    })
                    .onPreferenceChange(ScrollOffsetKey.self) { offset in
                        if offset > 100 && !isShowing {
                            action()
                        }
                    }
            }
        }

        struct ScrollOffsetKey: PreferenceKey {
            typealias Value = CGFloat
            static var defaultValue: CGFloat = 0
            
            static func reduce(value: inout CGFloat, nextValue: () -> CGFloat) {
                value = nextValue()
            }
        }

How do I add pull-to-refresh to lists in Combine with Swift?

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How do I add pull-to-refresh to lists in Combine with Swift?

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