User-5485716 posted
Is it possible to have a polymorphic array setup by json configuration?
E.g. the following code (all in one file only for the demo of course):
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using System.Threading;
using System.Threading.Tasks;
namespace PolymorphicConfigurationArray
{
public class Program
{
public static void Main(string[] args)
{
CreateHostBuilder(args).Build().Run();
}
public static IHostBuilder CreateHostBuilder(string[] args) =>
Host.CreateDefaultBuilder(args)
.ConfigureServices((hostContext, services) =>
{
services.Configure<ApplicationOptions>(hostContext.Configuration.GetSection("Application"));
services.AddHostedService<Worker>();
});
}
public class Worker : BackgroundService
{
private readonly ILogger<Worker> _logger;
public Worker(ILogger<Worker> logger, IOptions<ApplicationOptions> options)
{
_logger = logger;
logger.LogInformation($"Configuration Description {options.Value.Description}");
}
protected override async Task ExecuteAsync(CancellationToken stoppingToken)
{
while (!stoppingToken.IsCancellationRequested)
{
//_logger.LogInformation("Worker running at: {time}", DateTimeOffset.Now);
await Task.Delay(1000, stoppingToken);
}
}
}
public class ApplicationOptions
{
public string Description { get; set; }
public ConfigItem[] Items { get; set; }
}
public class ConfigItem
{
public string ItemName { get; set; }
}
public class ConfigItemWithValue : ConfigItem
{
public double ItemValue { get; set; }
}
}
The json file below may be used to intantiate the ApplicationOptions class with some ConfigItems in the Items array, however, I cannot see any way to get the derived ConfigItemWithValue class from configuration and thus having the Items array as a polymorphic
array.
Is this simply the limitation of json (key/value)?
I know that newtonsoft.json may serialize/deserialize such a graph by some typename options, is this possible to use in any way for configuration (without a lot of custom code of course)
{
"Logging": {
"LogLevel": {
"Default": "Information",
"Microsoft": "Warning",
"Microsoft.Hosting.Lifetime": "Information"
}
},
"Application": {
"Description": "Wondering how to achieve polymorphic array with json configuration",
"Items": [
{ "ItemName": "Name1" },
{ "ItemName": "Name2" }
]
}
}
