# Intent.Application.DependencyInjection.MediatR

This module handles dependency injection concerns around using MediatR.

MediatR is an open-source library for .NET applications that implements the Mediator pattern. It enables components in an application to communicate indirectly by sending messages (requests and notifications) to a central mediator. The mediator then dispatches these messages to their corresponding handlers, promoting loose coupling and separation of concerns. MediatR simplifies the implementation of the Mediator pattern in C# projects, leading to better code organization, testability, and maintenance in complex applications. It is a valuable tool for managing communication flow between components in modern .NET development.

This could be visualized in code as follows, which could be found in your dependency injection registrations:

```csharp
services.AddMediatR(cfg =>
{
    cfg.RegisterServicesFromAssembly(Assembly.GetExecutingAssembly());
    cfg.AddOpenBehavior(typeof(UnhandledExceptionBehaviour<,>));
    cfg.AddOpenBehavior(typeof(PerformanceBehaviour<,>));
    cfg.AddOpenBehavior(typeof(AuthorizationBehaviour<,>));
    cfg.AddOpenBehavior(typeof(ValidationBehaviour<,>));
    cfg.AddOpenBehavior(typeof(UnitOfWorkBehaviour<,>));
});
```

Any modules wanting to register up their own `PipelineBehaviour`s can do so using the `ContainerRegistrationRequest` event.

```csharp
ExecutionContext.EventDispatcher.Publish(ContainerRegistrationRequest.ToRegister($"typeof({ClassName}<,>)")
                .ForInterface("typeof(IPipelineBehavior<,>)")
                .WithPriority(4)
                .ForConcern("MediatR")
                .RequiresUsingNamespaces("MediatR")
                .HasDependency(this));
```

For more information on MediatR, check out their [official GitHub](https://github.com/jbogard/MediatR/).