Utils.DotNetCore.ServiceCollection - Get Config Value extension

A small utility library that extends Microsoft.Extensions.Configuration with strongly-typed helpers for retrieving configuration values in a safe and expressive way.

Features

• Strongly-typed configuration access – Retrieve values directly as int, bool, string, custom POCOs, etc.
• Nested key lookup – Pass multiple keys (params string[]) to walk through hierarchical configuration sections.
• Fail-fast or fallback options:
  • GetConfigurationValue<T> – throws if the key does not exist or cannot be bound.
  • GetConfigurationValueOrDefault<T> – returns a default value if the key is missing or null.

Installation

Add a reference to your project:

dotnet add package Utils.DotNetCore.ServiceCollection --version 1.0.1

Config file example

{
  "ConnectionStrings": {
    "Default": "Server=myserver;Database=mydb;User Id=sa;Password=secret;"
  },
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft": "Warning"
    }
  },
  "FeatureFlags": {
    "EnableNewUI": true
  }
}

Basic usage

namespace Sample.Use.Console
{
    internal class Program
    {
        static void Main(string[] args)
        {
            var builder = WebApplication.CreateBuilder(args);

            builder.Configuration.AddJsonFile("config.json", optional: false, reloadOnChange: true);

            IConfiguration configuration = builder.Configuration;

            var connectionString = configuration.GetConfigurationValue<string>("ConnectionStrings", "Default");
            System.Console.WriteLine(string.Concat("ConnectionStrings", ":", "Default", "=", connectionString));

            var enableNewUI = configuration.GetConfigurationValue<bool>("FeatureFlags", "EnableNewUI");
            System.Console.WriteLine(string.Concat("FeatureFlags", ":", "EnableNewUI", "=", enableNewUI));

            var maxRetries = configuration.GetConfigurationValueOrDefault(3, "AppSettings", "MaxRetries");
            System.Console.WriteLine(string.Concat("AppSettings", ":", "MaxRetries", "=", maxRetries));

            var loggingOptions = configuration.GetConfigurationValue<LoggingOptions>("Logging");
            System.Console.WriteLine(string.Concat("Logging", "=", loggingOptions.LogLevel["Default"]));

            System.Console.ReadLine();
        }
    }

    internal class LoggingOptions
    {
        public Dictionary<string, string> LogLevel { get; set; } = new();
    }
}

Nested section access

{
  "AppSettings": {
    "Logging": {
      "Enabled": true,
      "Level": "Debug"
    }
  }
}

bool loggingEnabled = config.GetConfigurationValue<bool>("AppSettings", "Logging", "Enabled");
string logLevel = config.GetConfigurationValue<string>("AppSettings", "Logging", "Level");

Using defaults for missed keys

int timeout = config.GetConfigurationValueOrDefault(30, "AppSettings", "Timeout");

Binding to complex types

public class LoggingOptions
{
    public bool Enabled { get; set; }
    public string Level { get; set; }
}

LoggingOptions options = config.GetConfigurationValue<LoggingOptions>("AppSettings", "Logging");

Comparison

Feature	IConfiguration.GetValue<T> (built-in)	GetConfigurationValue<T> (this library)	GetConfigurationValueOrDefault<T> (this library)
Supports nested hierarchical keys	❌ Only colon-delimited string keys	✅ Accepts multiple keys via params array	✅ Accepts multiple keys via params array
Throws if key does not exist	❌ Returns default(T) silently	✅ Throws KeyNotFoundException	❌ Returns provided default value
Throws if binding fails	❌ Returns default(T) silently	✅ Throws InvalidOperationException	❌ Returns provided default value
Provides safe defaults	✅ Requires specifying default(T) inline	❌ Always throws on missing/bad values	✅ Returns provided fallback value
Works with complex POCOs	❌ Only scalar values	✅ Supports binding to objects	✅ Supports binding to objects