This file provides a safe way to open URLs in SwiftUI applications.

View+OpenUrl.swift

//
//  View+OpenUrl.swift
//
//  Created by James Sedlacek on 11/26/24.
//

/// This file provides a safe way to open URLs in SwiftUI applications.
/// It adds a view modifier that handles URL opening with user confirmation
/// and multiple opening options (browser, in-app, or copy to clipboard).
///
/// Usage example:
/// ```swift
/// struct ContentView: View {
///     @State private var urlToOpen: URL?
///
///     var body: some View {
///         Button("Open Website") {
///             urlToOpen = URL(string: "https://example.com")
///         }
///         .open(url: $urlToOpen)
///     }
/// }
/// ```

import SwiftUI
import WebKit

/// Provides safe URL opening functionality to any SwiftUI View.
@MainActor
public extension View {
    /// Adds safe URL opening functionality with user confirmation.
    /// - Parameter url: A binding to an optional URL that should be opened.
    /// - Returns: A view with URL opening capabilities.
    func open(url: Binding<URL?>) -> some View {
        modifier(OpenURLModifier(url: url))
    }
}

@MainActor
struct OpenURLModifier {
    @Environment(\.openURL) private var openURL
    @Binding private var urlToOpen: URL?
    @State private var isConfirmationPresented = false
    @State private var isWebViewPresented = false
    @State private var isCopyAlertPresented = false

    init(url: Binding<URL?>) {
        self._urlToOpen = url
    }

    private func onURLChange(_ oldUrl: URL?, _ newUrl: URL?) {
        guard newUrl != nil else { return }
        isConfirmationPresented = true
    }

    private func copyLinkAction() {
        guard let linkString = urlToOpen?.absoluteString else { return }
        ClipboardService.copy(linkString)
        isCopyAlertPresented = true
    }

    private func openInBrowserAction() {
        guard let urlToOpen else { return }
        openURL(urlToOpen)
        resetURLAction()
    }

    private func openInAppAction() {
        isWebViewPresented = true
    }

    private func resetURLAction() {
        Task {
            // Add a small delay to allow animations to complete
            // and provide a better user experience when transitioning
            // between different states (alerts, sheets, etc.)
            try? await Task.sleep(for: .seconds(1))
            urlToOpen = nil
        }
    }
}

extension OpenURLModifier: ViewModifier {
    func body(content: Content) -> some View {
        content
            .onChange(of: urlToOpen, onURLChange)
            .confirmationDialog(
                .confirmationTitle,
                isPresented: $isConfirmationPresented,
                titleVisibility: .visible,
                actions: confirmationButtons
            )
            .alert(
                .copiedToClipboard,
                isPresented: $isCopyAlertPresented,
                actions: alertButtons
            )
            .sheet(
                isPresented: $isWebViewPresented,
                onDismiss: resetURLAction,
                content: webView
            )
    }

    @ViewBuilder
    private func confirmationButtons() -> some View {
        Button(.openInBrowser, action: openInBrowserAction)
        Button(.openInApp, action: openInAppAction)
        Button(.copyLink, action: copyLinkAction)
        Button(.cancel, role: .cancel, action: resetURLAction)
    }

    private func alertButtons() -> some View {
        Button(.ok, role: .cancel, action: resetURLAction)
    }

    @ViewBuilder
    private func webView() -> some View {
        if let urlToOpen {
            WebView(url: urlToOpen)
        }
    }
}

#if os(iOS)
typealias ViewRepresentable = UIViewRepresentable
#elseif os(macOS)
typealias ViewRepresentable = NSViewRepresentable
#endif

struct WebView: ViewRepresentable {
    let url: URL

    #if os(iOS)
    func makeUIView(context: Context) -> WKWebView {
        WKWebView()
    }

    func updateUIView(_ webView: WKWebView, context: Context) {
        webView.load(URLRequest(url: url))
    }
    #elseif os(macOS)
    func makeNSView(context: Context) -> WKWebView {
        WKWebView()
    }

    func updateNSView(_ webView: WKWebView, context: Context) {
        webView.load(URLRequest(url: url))
    }
    #endif
}

#if os(macOS)
import AppKit
#endif

struct ClipboardService {
    static func copy(_ string: String) {
        #if os(iOS)
        UIPasteboard.general.string = string
        #elseif os(macOS)
        NSPasteboard.general.clearContents()
        NSPasteboard.general.setString(string, forType: .string)
        #endif
    }
}

@MainActor
extension LocalizedStringKey {
    static let confirmationTitle = LocalizedStringKey("How would you like to handle this link?")
    static let openInBrowser = LocalizedStringKey("Open in Browser")
    static let openInApp = LocalizedStringKey("Open in App")
    static let copyLink = LocalizedStringKey("Copy Link")
    static let cancel = LocalizedStringKey("Cancel")
    static let copiedToClipboard = LocalizedStringKey("Copied to Clipboard")
    static let ok = LocalizedStringKey("OK")
}

I really like this idea! I'll work on updating it later today.

extension OpenURLModifier {
   private func binding(for option: PresentedOption) -> Binding<Bool> {
       Binding(
           get: { presentedOption == option },
           set: { presentedOption = $0 ? option : .none }
       )
   }
}

I think it's nice to model state in a enum but the closure based Binding has to be evaluated all the time which is ineffecient.

Yeah I just messed around with the enum idea and I think it makes sense to stick with what I have.