Delayed event bus for some delayed hanlding business
$ dotnet add package DelayedEvents.Abstractions
DelayedEvents is a library that provides a simple way to implement delayed message. For example: you can use it to implement when order is not paid in 15 minutes, cancel the order.
| Name | Version | Downloads |
|---|---|---|
| DelayedEvents.Abstractions |  |  |
| DelayedEvents.RabbitMq |  |  |
Add following nuget reference in business project:
PM> Install-Package DelayedEvents.Abstractions
And add following nuget reference in integration project:
PM> Install-Package DelayedEvents.RabbitMq
Make sure the plugins rabbitmq_delayed_message_exchange are enabled. https://blog.rabbitmq.com/posts/2015/04/scheduling-messages-with-rabbitmq/
First of all, you need to create a class that derived from the DelayedEvent class.
public class OrderPaymentCheckDelayedEvent : DelayedEvent
{
public OrderPaymentCheckDelayedEvent(Guid orderId)
{
OrderId = orderId;
DelayInSec = 15 * 60; // Make 15 minutes delay
}
public Guid OrderId { get; }
}Then, you need to create a class that derived from the DelayedEventHandler class.
public class OrderPaymentCheckDelayedEventHandler : DelayedEventHandler<OrderPaymentCheckDelayedEvent>
{
private readonly IOrderService _orderService;
public OrderPaymentCheckDelayedEventHandler(IOrderService orderService)
{
_orderService = orderService;
}
public override async Task Handle(OrderPaymentCheckDelayedEvent e)
{
// We will cancel the order if it is not paid in 15 minutes
await _orderService.CancelOrderIfNotPaidAsync(e.OrderId);
}
}Finally, you need to register the DelayedEventHandler in the Startup.cs file.
public void ConfigureServices(IServiceCollection services)
{
services.AddDelayedEvents()
.AddRabbitMq(options =>
{
options.HostName = "localhost";
options.UserName = "guest";
options.Password = "guest";
})
.AddDelayedEventHandler<OrderPaymentCheckDelayedEventHandler>();
}Ok! Now you can publish the DelayedEvent class in the business project.
public class OrderService : IOrderService
{
private readonly IDelayedEventPublisher _delayedEventPublisher;
public OrderService(IDelayedEventPublisher delayedEventPublisher)
{
_delayedEventPublisher = delayedEventPublisher;
}
public async Task CreateOrderAsync(Order order)
{
// Create order
// Publish the delayed event
await _delayedEventPublisher.PublishAsync(new OrderPaymentCheckDelayedEvent(order.Id));
}
}Leave a comment on GitHub if you have any questions or suggestions.
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This project is licensed under the MIT License