Most enterprise applications have a need for a simple in-memory event bus which implements the observer pattern through the pub/sub pattern . RCommon implements a simple dependency-free event bus for this utility but there are some advantages to using MediatR. MediatR is a mediator pattern implementation which can be used as an event bus. MediatR is a mature library and allows developers to use aspect oriented concepts to manipulate the request pipeline.
Copy using Examples . EventHandling . MediatR ;
using Microsoft . Extensions . Configuration ;
using Microsoft . Extensions . DependencyInjection ;
using Microsoft . Extensions . Hosting ;
using RCommon ;
using RCommon . EventHandling . Producers ;
using RCommon . MediatR ;
using RCommon . MediatR . Producers ;
using System . Diagnostics ;
using System . Reflection ;
using static System . Net . Mime . MediaTypeNames ;
try
{
var host = Host .CreateDefaultBuilder(args)
.ConfigureAppConfiguration((context , builder) =>
{
ConfigurationContainer . Configuration = builder
.Build();
})
.ConfigureServices(services =>
{
// Configure RCommon
services .AddRCommon()
.WithEventHandling < MediatREventHandlingBuilder > (eventHandling =>
{
eventHandling .AddProducer < PublishWithMediatREventProducer > ();
eventHandling .AddSubscriber < TestEvent, TestEventHandler > ();
});
}).Build();
}
catch ( Exception ex)
{
Console .WriteLine( ex .ToString());
}
Copy Console .WriteLine( "Example Starting" );
var eventProducers = host . Services .GetServices < IEventProducer > ();
var testEvent = new TestEvent ( DateTime . Now , Guid .NewGuid());
foreach ( var producer in eventProducers)
{
Console .WriteLine( $"Producer: {producer}" );
await producer .ProduceEventAsync(testEvent);
}
Console .WriteLine( "Example Complete" );
Console .ReadLine();
Copy using RCommon . EventHandling . Subscribers ;
using System ;
using System . Collections . Generic ;
using System . Diagnostics ;
using System . Linq ;
using System . Text ;
using System . Threading . Tasks ;
namespace Examples . EventHandling . MediatR
{
public class TestEventHandler : ISubscriber < TestEvent >
{
public TestEventHandler ()
{
}
public async Task HandleAsync ( TestEvent notification , CancellationToken cancellationToken = default )
{
Console .WriteLine( "I just handled this event {0}" , new object [] { notification .ToString() });
await Task . CompletedTask ;
}
}
}