TomRR.SourceGenerator.SettingsBinder 0.0.3

⚙️ SettingsBinder

A lightweight, zero-boilerplate Roslyn Source Generator that binds [Settings]-annotated classes directly to the .NET Options pattern.

✨ Features

• ✅ Automatic binding of settings from appsettings.json
• ✅ Strongly-typed configuration via [Settings] attribute
• ✅ Supports IOptions<T>, validation, and DI
• ✅ Source-generated SectionName and registration logic
• ✅ Zero reflection, minimal runtime overhead

🚀 Quick Start

1. Install NuGet Package

dotnet add package TomRR.SourceGenerator.SettingsBinder

2. Define a Settings Class

using TomRR.SourceGenerator.SettingsBinder;

[Settings]
public sealed partial class LoggingSettings : ISettings
{
    public static string SectionName => "LoggingSettings";

    public string? Level { get; init; }
    public string? Format { get; init; }
}

3. Add to appsettings.json

{
  "LoggingSettings": {
    "Level": "Information",
    "Format": "Json"
  }
}

4. Register with DI in Program.cs

var builder = WebApplication.CreateBuilder(args);

// Add base configuration files
builder.Configuration.AddConfigurationSources();

// Automatically registers all [Settings] classes
builder.AddSettingsOptions();

var app = builder.Build();

✅ What Gets Generated?

✅ Interface

public interface ISettings
{
    static abstract string SectionName { get; }
}

✅ Partial Class Implementation

public sealed partial class LoggingSettings : ISettings
{
    public static string SectionName => "LoggingSettings";
}

✅ Binding Extension

builder.Services
    .AddOptions<LoggingSettings>()
    .Bind(builder.Configuration.GetSection(LoggingSettings.SectionName))
    .ValidateDataAnnotations()
    .ValidateOnStart();

🧩 Customize Section Names

You can explicitly override the section name using the attribute:

[Settings("MyCustomSection")]
public sealed partial class AdvancedSettings : ISettings
{
    public string? Mode { get; init; }
    public bool Enabled { get; init; }
}

This generates:

public sealed partial class AdvancedSettings : ISettings
{
    public static string SectionName => "MyCustomSection";
}

{
  "MyCustomSection": {
    "Mode": "Debug",
    "Enabled": true
  }
}

🧠 Use this when the config section does not match the class name.

➕ Adding More Settings

Just define more [Settings]-annotated classes:

[Settings]
public sealed partial class ApiKeySettings : ISettings
{
    public string Key { get; init; } = default!;
}

All [Settings] classes are automatically picked up and registered.

📦 Package Info

📄 License

Licensed under the Apache License 2.0.