Network Connectivity Demo with SwiftUI

This SwiftUI app demonstrates how to use URLSessionConfiguration.waitsForConnectivity to handle network requests when there is no connectivity. The app includes a button to initiate a network request and provides feedback to the user about the network status using messages and an activity indicator.

Features

• A button to start a network request.
• An activity indicator to show the request is in progress.
• Messages to inform the user about the network status and request outcome.
• Use of waitsForConnectivity to wait for network availability instead of failing immediately.

Explanation of waitsForConnectivity

The waitsForConnectivity property of URLSessionConfiguration allows the app to wait for network connectivity if the device is currently offline. This is useful for making network requests more resilient to temporary connectivity issues.

Example Usage

Here's a snippet demonstrating the use of waitsForConnectivity in the app:

func fetchData(from url: URL) async throws -> Data {
    let configuration = URLSessionConfiguration.default
    configuration.waitsForConnectivity = true
    configuration.timeoutIntervalForResource = 60 // 60 seconds timeout for the whole resource load

    let session = URLSession(configuration: configuration)

    let (data, response) = try await session.data(from: url)

    guard let httpResponse = response as? HTTPURLResponse, (200...299).contains(httpResponse.statusCode) else {
        throw URLError(.badServerResponse)
    }

    return data
}

In this example:

- `waitsForConnectivity` is set to `true`, meaning the request will wait for network connectivity to be restored rather than failing immediately.
- `timeoutIntervalForResource` is set to 60 seconds, specifying the maximum amount of time to wait for the request to complete, including waiting for connectivity.

## App Structure

- **ContentView**: The main view containing the button, activity indicator, and messages.
- **startNetworkRequest**: A function that initiates the network request and updates the UI state.
- **fetchData**: A function that performs the actual network request using `URLSession`.

## How to Run the App

1. Clone the repository.
2. Open the project in Xcode.
3. Run the app on a simulator or a real device.
4. Press the "Start Network Request" button to initiate a network request.

## Requirements

- iOS 14.0+
- Xcode 12.0+
- Swift 5.3+

## License

This project is licensed under the MIT License - see the [LICENSE](LICENSE) file for details.

## Acknowledgements

- Apple Developer Documentation on [URLSessionConfiguration](https://developer.apple.com/documentation/foundation/urlsessionconfiguration)
- SwiftUI documentation and examples

## Contact

For any questions or feedback, please open an issue or contact the maintainer.