Net4x.DependencyInjectionLibrary 2.0.0

DependencyInjectionLibrary

A small helper library that wires Microsoft.Extensions.DependencyInjection and configuration into a simple, convention-driven registration flow. It is intended to simplify test and application bootstrapping by allowing registration of service mappings via code and configuration JSON located next to an assembly.

Key components

• DependencyInjectionUtility � orchestrates building the IConfiguration, IServiceCollection and IServiceProvider. It looks for an appsettings.json file next to the executing assembly (or a path provided via an environment variable) and supports different configuration loading strategies depending on the target runtime.

• ServiceProviderContainer / ServiceProviderContainerInternal � singleton holder that stores the created IServiceProvider, IServiceCollection and an array of DependencyInjectionItem definitions. ServiceProviderContainer.Instance implements IServiceProviderContainer and exposes AddClassesToDependencyInjection which the utility invokes to register services.

• DependencyInjectionItem � small model that describes a service registration: a BaseType (service interface/base), ConcreteType (implementation) and LifeCycle (Transient, Scoped, Singleton).

• DependencyInjectionConfigurationBuilder � thin extension of ConfigurationBuilder used by the utility to provide logging and JSON configuration helpers.

• DependencyInjectionExtender � extension entry point (calls into the ServiceProviderContainer) that simplifies creating the service provider from code by passing DependencyInjectionItem instances.

Usage example

1. Define your services and implementations:

   public interface IMyService { }
   public class MyService : IMyService { }
   

2. Register them at startup (the extension expects a Type instance; commonly typeof(Program) or any type from your assembly):

   using DependencyInjectionLibrary;
   
   var provider = typeof(Program).ConfigureDependencyInjection(
    new DependencyInjectionItem(DependencyInjectionLibrary.Enums.LifeCycle.Singleton, typeof(IMyService), typeof(MyService))
   );
   
   var myService = provider.GetService<IMyService>();
   

3. Alternatively obtain the global container and access configuration/services later:

   var container = ServiceProviderContainer.Instance;
   var serviceProvider = container.ServiceProvider;
   var config = container.Config; // IConfigurationRoot built from appsettings.json
   

Configuration file location

• The utility looks for an appsettings.json file in the directory of the provided Type's assembly by default.
• You may override the path by setting an environment variable whose name is passed to ConfigureDependencyInjection inside the library. When present the variable's value is used as the directory containing appsettings.json.
• On modern runtimes the JSON may be loaded from a memory stream (the library uses an in-memory JSON string when appropriate), while older runtimes (e.g. .NET Framework 4.0) load the JSON directly from file.

Notes and recommendations

• DependencyInjectionItem controls registration lifetime via the LifeCycle enum (Transient, Scoped, Singleton).
• The library registers IConfiguration as a singleton for consumers to resolve.
• The extension method entry point wires the ServiceProviderContainer.Instance with the created IServiceProvider so other parts of an app or tests can reuse the same container.
• This library is lightweight and intended primarily for bootstrapping and tests. For advanced DI scenarios rely on the full Microsoft.Extensions.DependencyInjection APIs directly.

License / Contributing

See repository root for license and contribution guidelines.