Can't load options from appsettings in ASP.NET Core site using IOptions

Question

I'm trying to load data from my appsettings file in an ASP.NET Core project. I've done it before, but now I can't get it to work. Furthermore, I'm trying to configure a section names Images and bind it against an object of type WorkImageOptions, which contains info about a collection of images.

I try to retrieve the values using IOptionsSnapshot, but it's always empty if, though there's data in the settings section.

Program.cs:

using SLT.Bohem63.Peachie.Config;

WebApplicationBuilder builder = WebApplication.CreateBuilder(args);
builder.Services
    .Configure<WorkImageOptions>(builder.Configuration.GetSection(WorkImageOptions.SectionName));

builder.Services.AddControllersWithViews();

WebApplication app = builder.Build();

app.UseRouting();
app.MapStaticAssets();

app.MapControllerRoute(
    name: "default",
    pattern: "{controller=Bohem63}/{action=Index}/{id?}")
    .WithStaticAssets();

app.Run();

WorkImageOptions.cs:

public sealed class WorkImageOptions
{
    public IEnumerable<WorkImageInfo> Images { get; set; }

    public static string SectionName => "Images";
}

WorkImageInfo.cs:

namespace SLT.Bohem63.Peachie.Models.Data
{
    public interface IWorkImageInfo
    {
        string Filename { get; set; }
        string Title { get; set; }
        string Description { get; set; }
        int Likes { get; set; }
    }

    public sealed class WorkImageInfo : IWorkImageInfo
    {
        public string Filename { get; set; }
        public string Title { get; set; }
        public string Description { get; set; }
        public int Likes { get; set; } = 0;
    }
}

Retrieve options:

public class Bohem63Controller(IOptionsSnapshot<WorkImageOptions> options) : Controller { }

appsettings.json:

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft.AspNetCore": "Warning"
    }
  },
  "AllowedHosts": "*",
  "Images": {
    "filename": "pic1.jpg",
    "title": "",
    "description": "",
    "likes": 0
  }
}

Your class WorkImageOptions contains a collection IEnumerable<WorkImageInfo> Images, but in your JSON "Images" is not a collection, but a single object. — Orion
– Orion, Commented Jan 15 at 0:09

Ivan Petrov · Accepted Answer · 2025-01-15 00:18:51Z

1

With the current structure, appsettings.json has to look like this for it to work:

"Images": {
  "Images": [
    {
      "filename": "foo.jpg",
      "title": "bar",
      "description": "baz",
      "likes": 42
    }
  ]
}

although I'd change things a bit by getting rid of the SectionName property and use nameof with the class name instead:

builder.Services
    .Configure<WorkImageOptions>(builder.Configuration.GetSection(nameof(WorkImageOptions)));

appsettings.json:

"WorkImageOptions": {
  "Images": [
    {
      "filename": "foo.jpg",
      "title": "bar",
      "description": "baz",
      "likes": 42
    }
  ]
}

edited Jan 15 at 0:18

answered Jan 15 at 0:12

Ivan Petrov

7,3392 gold badges15 silver badges31 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Can't load options from appsettings in ASP.NET Core site using IOptions

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related