RemoteContentView

The RemoteContentView can download a remote content from a URL and display different loading states.

The package supports JSON and Plist (using Foundation Decodable protocol), images, and custom types.

You must provide a view to display the result value, and optionally a view for each loading state.

Loading and Displaying JSON Data

Displaying the list of posts received from the JSONPlaceholder API. The Post struct conforms to Codable protocol used for JSON decoding.

struct Post : Codable {

    var id: Int

    var title: String

    var body: String
}

let url = URL(string: "https://jsonplaceholder.typicode.com/posts")!

let content = DecodableRemoteContent(url: url, type: [Post].self, decoder: JSONDecoder())

let view = RemoteContentView(remoteContent: content) { posts in
    List(posts, id: \Post.id) { post in
        VStack {
            Text(post.title)
            Text(post.body)
        }
    }
}

Note, if you use default JSON decoder you can omit the last parameter:

let content = DecodableRemoteContent(url: url, type: [Post].self)

Loading and Displaying an Image

let url = URL(string: "http://optipng.sourceforge.net/pngtech/img/lena.png")!

let remoteImage = RemoteImage(url: url)

let view = RemoteContentView(remoteContent: remoteImage) {
    Image(uiImage: $0)
}

Loading States

RemoteContentView supports 4 customizable loading states:

let view = RemoteContentView(remoteContent: remoteContent,
                             empty: {
                                EmptyView()
                             },
                             progress: { progress in
                                Text("Loading in progress: \(progress)")
                             },
                             failure: { error, retry in
                                VStack {
                                    Text(error)
                                    Button("Retry", action: retry)
                                }
                             },
                             content: { posts in
                                List(posts, id: \Post.id) { post in
                                    VStack {
                                        Text(post.title)
                                        Text(post.body)
                                    }
                                }
                            })

Implementing Custom RemoteContent

The RemoteContent protocol defines objects that provide content and manage loading state.

public protocol RemoteContent : ObservableObject {

    associatedtype Value
    
    associatedtype Progress

    var loadingState: RemoteContentLoadingState<Value, Progress> { get }

    func load()

    func cancel()
}

The package provides two implementations:

DecodableRemoteContent for a content, loaded from a URL, represented by Decodable objects;
RemoteImage for images.

You can implement your own RemoteContent object if you need custom loading or to make the view work with existing content providers. You can find an example in CustomRemoteContent.playground.