Ecng.Configuration 1.0.255

Ecng.Configuration

A lightweight and efficient configuration management library for .NET applications, providing typed access to configuration sections, application settings, and a flexible service registry.

Overview

Ecng.Configuration wraps and extends the .NET System.Configuration framework, offering:

• Type-safe access to configuration sections and groups
• Service registry pattern for dependency injection and service location
• Event-driven notifications for service registration
• AppSettings helpers with type conversion
• Thread-safe operations for concurrent access

Installation

This library requires:

• .NET Standard 2.0+ or .NET 6.0+
• System.Configuration.ConfigurationManager package

<PackageReference Include="System.Configuration.ConfigurationManager" />

Key Features

1. Configuration Sections

Access configuration sections by type or name with built-in caching for performance.

Access by Type

using Ecng.Configuration;

// Get a custom configuration section by type
var section = ConfigManager.GetSection<MyCustomSection>();

// Section will be null if not found
if (section != null)
{
    // Use the section
    var value = section.SomeProperty;
}

Access by Name

// Get section by name
var connectionStrings = ConfigManager.GetSection<ConnectionStringsSection>("connectionStrings");

// Or without type parameter
var section = ConfigManager.GetSection("mySection");

Example Configuration File

<configuration>
  <configSections>
    <section name="mySection" type="MyNamespace.MyCustomSection, MyAssembly"/>
  </configSections>

  <mySection someProperty="value" />
</configuration>

2. Configuration Section Groups

Organize related configuration sections into groups.

// Get a section group by type
var group = ConfigManager.GetGroup<MyConfigurationGroup>();

// Get a section group by name
var systemWeb = ConfigManager.GetGroup<SystemWebSectionGroup>("system.web");

3. Application Settings

Simple access to AppSettings with type conversion support.

// Get a setting with default value
int timeout = ConfigManager.TryGet<int>("RequestTimeout", 30);

// Get a boolean setting
bool enableLogging = ConfigManager.TryGet<bool>("EnableLogging", false);

// Get a string setting
string apiUrl = ConfigManager.TryGet<string>("ApiUrl", "https://default-api.com");

// Direct access to all AppSettings
var allSettings = ConfigManager.AppSettings;
foreach (string key in allSettings.AllKeys)
{
    Console.WriteLine($"{key} = {allSettings[key]}");
}

Configuration File:

<configuration>
  <appSettings>
    <add key="RequestTimeout" value="60" />
    <add key="EnableLogging" value="true" />
    <add key="ApiUrl" value="https://api.example.com" />
  </appSettings>
</configuration>

4. Service Registry

A lightweight service locator pattern for managing application services without heavy DI frameworks.

Register Services

// Register a service with default name (type's AssemblyQualifiedName)
var securityProvider = new CollectionSecurityProvider(securities);
ConfigManager.RegisterService<ISecurityProvider>(securityProvider);

// Register a service with a custom name
ConfigManager.RegisterService<ILogger>("FileLogger", new FileLogger());
ConfigManager.RegisterService<ILogger>("ConsoleLogger", new ConsoleLogger());

Retrieve Services

// Get a service by type (using default name)
var provider = ConfigManager.GetService<ISecurityProvider>();

// Get a service by name
var fileLogger = ConfigManager.GetService<ILogger>("FileLogger");
var consoleLogger = ConfigManager.GetService<ILogger>("ConsoleLogger");

// Try to get a service (returns default if not found)
var optionalService = ConfigManager.TryGetService<IOptionalFeature>();
if (optionalService != null)
{
    // Service is available
}

Check Service Registration

// Check if a service is registered
if (ConfigManager.IsServiceRegistered<IMessageAdapter>())
{
    var adapter = ConfigManager.GetService<IMessageAdapter>();
}

// Check by name
if (ConfigManager.IsServiceRegistered<ILogger>("FileLogger"))
{
    // Use the file logger
}

Conditional Registration

// Register only if not already registered
ConfigManager.TryRegisterService<IDefaultService>(new DefaultServiceImpl());

// This won't override the existing registration
ConfigManager.TryRegisterService<IDefaultService>(new AnotherImpl());

Get All Services of a Type

// Get all registered services of a specific type
var allLoggers = ConfigManager.GetServices<ILogger>();

foreach (var logger in allLoggers)
{
    logger.Log("Application started");
}

5. Service Registration Events

React to service registration with event handlers or subscriptions.

Global Event Handler

// Subscribe to all service registrations
ConfigManager.ServiceRegistered += (type, service) =>
{
    Console.WriteLine($"Service registered: {type.Name}");
};

// Now register a service
ConfigManager.RegisterService<IMyService>(new MyServiceImpl());
// Output: Service registered: IMyService

Type-Specific Subscription

// Subscribe to a specific service type registration
ConfigManager.SubscribeOnRegister<ISecurityProvider>(provider =>
{
    Console.WriteLine($"SecurityProvider registered with {provider.Count} securities");
    // Initialize or configure the provider
});

// When this service is registered, the callback will be invoked
ConfigManager.RegisterService<ISecurityProvider>(new CollectionSecurityProvider(securities));

6. Service Fallback

Provide a fallback mechanism to create services on-demand when they're not registered.

// Set up a service fallback handler
ConfigManager.ServiceFallback += (type, name) =>
{
    // Create services dynamically based on type
    if (type == typeof(ILogger))
    {
        return new DefaultLogger();
    }

    if (type == typeof(ICache))
    {
        return new MemoryCache();
    }

    // Return null to indicate service cannot be created
    return null;
};

// Now getting an unregistered service will use the fallback
var logger = ConfigManager.GetService<ILogger>(); // Creates DefaultLogger

7. Access Underlying Configuration

For advanced scenarios, access the underlying .NET Configuration object.

// Get the underlying Configuration object
var config = ConfigManager.InnerConfig;

if (config != null)
{
    Console.WriteLine($"Configuration file: {config.FilePath}");

    // Access sections directly
    foreach (ConfigurationSection section in config.Sections)
    {
        Console.WriteLine($"Section: {section.SectionInformation.Name}");
    }
}

Complete Usage Example

Here's a complete example showing typical usage in an application:

using Ecng.Configuration;
using System;

namespace MyApplication
{
    public class Program
    {
        static void Main(string[] args)
        {
            // 1. Configure service fallback (optional)
            ConfigManager.ServiceFallback += CreateDefaultServices;

            // 2. Subscribe to service registrations (optional)
            ConfigManager.SubscribeOnRegister<ILogger>(logger =>
            {
                logger.Initialize();
            });

            // 3. Register core services
            ConfigManager.RegisterService<ILogger>(new FileLogger("app.log"));
            ConfigManager.RegisterService<IExchangeInfoProvider>(
                new InMemoryExchangeInfoProvider()
            );

            // 4. Register multiple implementations with names
            ConfigManager.RegisterService<ICache>("Memory", new MemoryCache());
            ConfigManager.RegisterService<ICache>("Distributed", new RedisCache());

            // 5. Read application settings
            var timeout = ConfigManager.TryGet<int>("Timeout", 30);
            var apiUrl = ConfigManager.TryGet<string>("ApiUrl");

            // 6. Get configuration section
            var customSection = ConfigManager.GetSection<CustomAppSettings>();

            // 7. Use services throughout your application
            RunApplication();
        }

        static void RunApplication()
        {
            // Retrieve services when needed
            var logger = ConfigManager.GetService<ILogger>();
            logger.Log("Application started");

            var provider = ConfigManager.GetService<IExchangeInfoProvider>();
            var exchanges = provider.GetExchanges();

            // Use named service
            var cache = ConfigManager.GetService<ICache>("Memory");
            cache.Set("key", "value");
        }

        static object CreateDefaultServices(Type type, string name)
        {
            // Provide default implementations
            if (type == typeof(ILogger))
                return new ConsoleLogger();

            return null;
        }
    }

    // Example interfaces
    public interface ILogger
    {
        void Initialize();
        void Log(string message);
    }

    public interface IExchangeInfoProvider
    {
        IEnumerable<Exchange> GetExchanges();
    }

    public interface ICache
    {
        void Set(string key, string value);
        string Get(string key);
    }
}

Thread Safety

All operations in ConfigManager are thread-safe:

• Configuration sections and groups are cached on first access
• Service registry operations use locking to prevent race conditions
• Multiple threads can safely register and retrieve services concurrently

// Safe to call from multiple threads
Parallel.For(0, 100, i =>
{
    var service = ConfigManager.GetService<IMyService>();
    service.DoWork();
});

Best Practices

1. Register Services at Application Startup

// Register all services during application initialization
public static void ConfigureServices()
{
    ConfigManager.RegisterService<ILogger>(new Logger());
    ConfigManager.RegisterService<IDataService>(new DataService());
    // ... register other services
}

2. Use Type-Safe Access

// Prefer type-safe access over string-based access
var section = ConfigManager.GetSection<MySection>();  // Good
var section = (MySection)ConfigManager.GetSection("mySection");  // Less safe

3. Provide Defaults for AppSettings

// Always provide sensible defaults
var timeout = ConfigManager.TryGet<int>("Timeout", 30);  // Good
var timeout = ConfigManager.TryGet<int>("Timeout");  // May return 0

4. Check Service Registration Before Use

// For optional services, check registration first
if (ConfigManager.IsServiceRegistered<IOptionalFeature>())
{
    var feature = ConfigManager.GetService<IOptionalFeature>();
    feature.Execute();
}

5. Use Named Services for Multiple Implementations

// Register different implementations with descriptive names
ConfigManager.RegisterService<IRepository>("User", new UserRepository());
ConfigManager.RegisterService<IRepository>("Product", new ProductRepository());

// Retrieve specific implementation
var userRepo = ConfigManager.GetService<IRepository>("User");

Common Patterns

Singleton Services

// Register singleton services
var singletonService = new MySingletonService();
ConfigManager.RegisterService<IMySingletonService>(singletonService);

// Every call returns the same instance
var service1 = ConfigManager.GetService<IMySingletonService>();
var service2 = ConfigManager.GetService<IMySingletonService>();
// service1 == service2

Factory Pattern with Fallback

// Use fallback as a factory
ConfigManager.ServiceFallback += (type, name) =>
{
    if (type == typeof(IDataService))
    {
        // Create with dependencies
        var logger = ConfigManager.GetService<ILogger>();
        return new DataService(logger);
    }
    return null;
};

// First call creates and registers the service
var service = ConfigManager.GetService<IDataService>();

Configuration-Driven Service Selection

// Select service implementation based on configuration
var loggerType = ConfigManager.TryGet<string>("LoggerType", "Console");

ILogger logger = loggerType switch
{
    "File" => new FileLogger(),
    "Console" => new ConsoleLogger(),
    "Database" => new DatabaseLogger(),
    _ => new ConsoleLogger()
};

ConfigManager.RegisterService<ILogger>(logger);

Migration from .NET ConfigurationManager

If you're migrating from using ConfigurationManager directly:

// Before:
var setting = ConfigurationManager.AppSettings["MySetting"];

// After:
var setting = ConfigManager.AppSettings["MySetting"];
// Or with type conversion:
var typedSetting = ConfigManager.TryGet<int>("MySetting", 0);

// Before:
var section = (MySection)ConfigurationManager.GetSection("mySection");

// After:
var section = ConfigManager.GetSection<MySection>("mySection");

Limitations

• Configuration file must exist and be valid at application startup
• Configuration sections are cached on first load (not reloaded automatically)
• Service registry is in-memory only (not persisted)
• Not a replacement for full dependency injection frameworks (suitable for simpler scenarios)

See Also

• System.Configuration documentation
• ConfigurationManager class

License

Part of the StockSharp/Ecng framework.