How do I implement pull to refresh in SwiftUI?

There are two main approaches to implementing pull-to-refresh functionality in SwiftUI, depending on your SwiftUI version and desired level of customization:

1. Using the built-in refreshable modifier (iOS 16+)

If you’re targeting iOS 16 and above, SwiftUI offers a built-in refreshable modifier that simplifies pull-to-refresh functionality for List and ScrollView. Here’s how to use it:

struct MyListView: View {
  @State private var items = ["Item 1", "Item 2", "Item 3"]

  var body: some View {
    List {
      ForEach(items) { item in
        Text(item)
      }
    }
    .refreshable {
      // Perform your data refresh logic here (e.g., network call)
      DispatchQueue.main.asyncAfter(deadline: .now() + 2) {  // Simulate data fetching
        items.append("New Item")
      }
    }
  }
}

In this example

We define a List containing our data.
We apply the refreshable modifier to the List.
Inside the refreshable closure, we place the code that fetches new data (replace the simulated delay with your actual data fetching logic).
When the user pulls down to refresh, the closure executes, retrieves new data (simulated here with a delay), and updates the items state variable, triggering a re-render of the list with the new data.

2. Using a third-party library (For all SwiftUI versions or more customization)

For SwiftUI versions below 16 or if you need more customization options, consider using a third-party library like SwiftUIPullToRefresh. This library offers greater control over the pull-to-refresh behavior, including:

Customizable progress indicator
Specifying when the refresh operation ends
Support for async/await syntax

Here’s a basic example using SwiftUIPullToRefresh:

import SwiftUIPullToRefresh

struct MyListView: View {
  @State private var items = ["Item 1", "Item 2", "Item 3"]
  @State private var isRefreshing = false

  var body: some View {
    List {
      ForEach(items) { item in
        Text(item)
      }
    }
    .pullToRefresh(isRefreshing: $isRefreshing) {
      // Perform your data refresh logic here (e.g., network call)
      DispatchQueue.main.asyncAfter(deadline: .now() + 2) {
        items.append("New Item")
        isRefreshing = false  // Signal refresh completion
      }
    }
  }
}

In this exmaple

We import the SwiftUIPullToRefresh library.
We use the pullToRefresh modifier, binding the isRefreshing state variable to control the refresh indicator’s visibility.
Inside the closure, we update the item state and set isRefreshing to false to indicate refresh completion, triggering the UI update.

Remember to follow the library’s specific instructions for installation and usage.

Choose the approach that best suits your SwiftUI version and customization needs. Both methods effectively implement pull-to-refresh functionality, enhancing your app’s user experience.

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