Injectable.NetCore.Extensions 1.4.0

Injectable.NetCore.Extensions

Injectable Extensions enable simple, convention-based injection for .Net Core and .Net Standard services.

Injectable Extensions streamlines dependency injection in .Net Core and .Net Standard development scenarios by providing a set of extensions methods which enable convention-based injection from loaded assemblies. The extensions can be used directly from any IServiceCollection, or a broader set of injection rules can be provided via the InjectionSettings class.

Installation

From Package Manager Console:

Install-Package Injectable.NetCore.Extensions

From Cli:

dotnet add package Injectable.NetCore.Extensions

Injection Scopes

Injectable Extensions supports three forms of injection scopes provided by the InjectionMode enum:

namespace Injectable.NetCore.Extensions
{
    public enum InjectionMode
    {
        Scoped,
        Singleton,
        Transient
    }
}

InjectionSettings

This is the definition of the IInjectionSettings interface. Any implementation of this interface can be passed into the InjectByConvention method.

Usage 1: Fluent Injection

There is a fluent method for configuring the IInjectionSettings in the package that will guide you through the completion of valid settings.

If your interface declarations are:

namespace MyNamespace.ServiceContracts {

    public interface IPersonService {}
    public interface IAddressService {}
}
namespace MyUfoNamespace {
    public interface IUfoService {}
}

By convention, your implementations are:

namespace MyOtherNamespace.Services {

    public class PersonService: IPersonService {}
    public class AddressService: IAddressService {}
    public class UfoService: IUfoService {}
}

This method of injection will look similar to this:

public void ConfigureServices(IServiceCollection services){
    
    var injectionSettings = InjectionSettings
        .WithInjectionMode(InjectionMode.Scoped)
        .WithRootNamespaces("MyNamespace", "MyUfoNamespace")
        .AllowImplementationsInAnyNamespace()
        .WithInterfacePrefix("I")
        .WithInterfaceSuffix("Service")
        .WithStrictNaming();

    services.InjectByConvention(injectionSettings);
}

This will result in All Interfaces starting with "I" and ending in "Service" residing anywhere in the InjectionClasses or InjectionClasses2 namespaces with implementations whose class names match the interface names (without the prefix). Since multiple root namespaces were specified, all the implementations will be injected.

Usage 2: Explicit Scope Injection

Explicit extension methods exist for each type of scope by providing a root namespace and suffix. So if my convention for naming your service interfaces is "I<ClassName>Service" (we default the prefix to "I", but that can also be overriden)

If your interface declarations are:

namespace MyNamespace.ServiceContracts {

    public interface IPersonService {}
    public interface IAddressService {}
    public interface IUfoService {}
}

By convention, your implementations are:

namespace MyOtherNamespace.Services {

    public class PersonService: IPersonService {}
    public class AddressService: IAddressService {}
    public class UfoService: IUfoService {}
}

Then injecting those into your services is as easy as:

public void ConfigureServices (IServiceCollection services) {

    // Transient injection
    services.InjectTransientsFrom("MyNamespace", "Services");
    // Scoped injection
    services.InjectScopedFrom("MyNamespace", "Services");
    // Singleton injection
    services.InjectSingletonsFrom("MyNamespace", "Services");
}

There are many optional parameters to the Inject extenstions that allow you to customize the behavior which all roll up into an InjectionSettings instance before being passed into the InjectByConvention method.

Reflection, Injection, and Multiple Implementations

I realize there is nothing that prevents or restricts the implementation of an interface on multiple classes. HOWEVER, there is a limitation on this imposed by the dependency injection process that does not allow multiple implementations for injected types. This will cause an error.

Change Log