libMacSparkle

Overview

libMacSparkle wraps the Sparkle framework to provide a simple C interface for:

• Initializing updater
• Checking for updates manually

The API design is inspired by WinSparkle, providing a similar C interface for cross-platform applications.

Quickstart

Step 1: Download Dependencies

1. Download Sparkle.framework from the official Sparkle website
2. Download the latest libMacSparkle zip file from latest GitHub Releases

Extract both and place them in your application’s bundle or alongside your executable.

Step 2: Configure Info.plist

Your application’s Info.plist file must include the following entries for Sparkle to function correctly:

Required Entries:

• CFBundleIdentifier: Your application’s unique bundle identifier (e.g., com.yourcompany.yourapp)
• CFBundleVersion: The build version (e.g., 100 or 1.0.0)
• CFBundleShortVersionString: The display version shown to users (e.g., 1.0.0)
• SUFeedURL: The URL to your appcast feed.
• SUPublicEDKey: Your EdDSA public key for signature verification.

Example Info.plist:

<key>CFBundleIdentifier</key>
<string>com.yourcompany.yourapp</string>
<key>CFBundleVersion</key>
<string>1.0.0</string>
<key>CFBundleShortVersionString</key>
<string>1.0.0</string>

<key>SUFeedURL</key>
<string>https://example.com/updates/appcast.xml</string>
<key>SUPublicEDKey</key>
<string>your-eddsa-public-key-here</string>

Step 3: Create a Wrapper Class (C# Example)

Create a wrapper class to handle P/Invoke calls and initialization:

using System.Runtime.InteropServices;

internal static class MacSparkleWrapper
{
    private const string LIB = "libMacSparkle.dylib";

    [DllImport(LIB, EntryPoint = "mac_sparkle_set_appcast_url", CallingConvention = CallingConvention.Cdecl)]
    public static extern void mac_sparkle_set_appcast_url([MarshalAs(UnmanagedType.LPStr)] string url);

    [DllImport(LIB, EntryPoint = "mac_sparkle_init", CallingConvention = CallingConvention.Cdecl)]
    public static extern void mac_sparkle_init();

    [DllImport(LIB, EntryPoint = "mac_sparkle_check_update_with_ui", CallingConvention = CallingConvention.Cdecl)]
    public static extern void mac_sparkle_check_update_with_ui();

    public static void Initialize(string appcastUrl)
    {
        mac_sparkle_set_appcast_url(appcastUrl);
        mac_sparkle_init();
    }

    public static void CheckForUpdates()
    {
        mac_sparkle_check_update_with_ui();
    }
}

Step 4: Initialize on Application Startup

public class App
{
    public static void Main(string[] args)
    {
        if (OperatingSystem.IsMacOS())
        {
            try
            {
                MacSparkleWrapper.Initialize("https://example.com/updates/appcast.xml");
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Failed to initialize Sparkle: {ex.Message}");
            }
        }

        // Continue with your application startup...
    }
}

Step 5: Check for Updates (Optional)

Add a “Check for Updates” menu item or button:

private void OnCheckForUpdatesClicked(object sender, EventArgs e)
{
    if (OperatingSystem.IsMacOS())
    {
        try
        {
            MacSparkleWrapper.CheckForUpdates();
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Failed to check for updates: {ex.Message}");
        }
    }
}

Development

Install dependencies.

swift package resolve

Build the library using the provided build script:

./build.sh

This will generate libMacSparkle.dylib in the .build/universal/release directory.

Public API

The library exposes the following C functions via mac_sparkle.h:

mac_sparkle_set_appcast_url

void mac_sparkle_set_appcast_url(const char* url);

Sets the appcast URL for Sparkle. This allows you to programmatically set the feed URL instead of relying on Info.plist. Must be called before mac_sparkle_init.

mac_sparkle_init

void mac_sparkle_init(void);

Initializes the Sparkle updater. Must be called first time after UI started.

mac_sparkle_check_update_with_ui

void mac_sparkle_check_update_with_ui(void);

Triggers a manual update check with user interface feedback.

Platform Considerations

• macOS Only: This library only works on macOS. Ensure you guard calls with platform checks:

  if (OperatingSystem.IsMacOS())
  {
      // Call MacSparkle functions
  }

• Library Placement: Ensure libMacSparkle.dylib and Sparkle.framework are in your application’s bundle or in a location where the system can find it (e.g., alongside your executable or in @rpath).

Examples

See the examples/csharp directory for complete working examples:

• MacSparkleAvaloniaUIDemo - Avalonia UI example
• MacSparkleDotnetMacOSDemo - .NET macOS example

License

See LICENSE file for details.