TheXamlGuy/Framework/Core/Configurations/WritableJsonConfigurationSource.cs

using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Configuration.Json;
using Microsoft.Extensions.FileProviders;

namespace TheXamlGuy.Framework.Core
{
    public class WritableJsonConfigurationSource : JsonConfigurationSource
    {
        public IWritableJsonConfigurationBuilder? Factory { get; set; }

        public override IConfigurationProvider Build(IConfigurationBuilder builder)
        {
            EnsureDefaultsWithSteam(builder);
            return new WritableJsonConfigurationProvider(this);
        }
        
        private void EnsureDefaultsWithSteam(IConfigurationBuilder builder)
        {
            EnsureDefaults(builder);

            if (FileProvider is PhysicalFileProvider physicalFileProvider)
            {
                string? outputFile = System.IO.Path.Combine(physicalFileProvider.Root, Path);
                Factory?.Build(outputFile);
            }
        }
    }
}