public async Task <ActionResult> UpdateserviceListItemAsync([FromBody] ServiceListItem serviceListItemToUpdate)
{
var ServiceListItem = await _serviceListContext.ServiceListItems.SingleOrDefaultAsync(i => i.Id == serviceListItemToUpdate.Id);
if (ServiceListItem == null)
{
return(NotFound(new { Message = $"Item with id {serviceListItemToUpdate.Id} not found." }));
}
var oldPrice = ServiceListItem.Price;
var raiseserviceListItemPriceChangedEvent = oldPrice != serviceListItemToUpdate.Price;
// Update current serviceListItem
ServiceListItem = serviceListItemToUpdate;
_serviceListContext.ServiceListItems.Update(ServiceListItem);
if (raiseserviceListItemPriceChangedEvent) // Save serviceListItem's data and publish integration event through the Event Bus if price has changed
{
//Create Integration Event to be published through the Event Bus
var priceChangedEvent = new ServiceListPriceChangedIntegrationEvent(ServiceListItem.Id, serviceListItemToUpdate.Price, oldPrice);
// Achieving atomicity between original Catalog database operation and the IntegrationEventLog thanks to a local transaction
await _catalogIntegrationEventService.SaveEventAndServiceListContextChangesAsync(priceChangedEvent);
// Publish through the Event Bus and mark the saved event as published
await _catalogIntegrationEventService.PublishThroughEventBusAsync(priceChangedEvent);
}
else // Just save the updated serviceListItem because the serviceListItem's Price hasn't changed.
{
await _serviceListContext.SaveChangesAsync();
}
return(CreatedAtAction(nameof(ItemByIdAsync), new { id = serviceListItemToUpdate.Id }, null));
}
public async Task Handle(ServiceListPriceChangedIntegrationEvent @event)
{
using (LogContext.PushProperty("IntegrationEventContext", $"{@event.Id}-{Program.AppName}"))
{
_logger.LogInformation("----- Handling integration event: {IntegrationEventId} at {AppName} - ({@IntegrationEvent})", @event.Id, Program.AppName, @event);
var serviceListItem = _serviceListContext.ServiceListItems.Where(l => l.Id == @event.ServiceListId).FirstOrDefault();
serviceListItem.PriceAfterDiscount = @event.NewPrice;
await _serviceListContext.SaveChangesAsync();
}
}
public async Task SaveEventAndServiceListContextChangesAsync(IntegrationEvent evt)
{
_logger.LogInformation("----- CatalogIntegrationEventService - Saving changes and integrationEvent: {IntegrationEventId}", evt.Id);
//Use of an EF Core resiliency strategy when using multiple DbContexts within an explicit BeginTransaction():
//See: https://docs.microsoft.com/en-us/ef/core/miscellaneous/connection-resiliency
await ResilientTransaction.New(_ServiceListContext).ExecuteAsync(async() =>
{
// Achieving atomicity between original catalog database operation and the IntegrationEventLog thanks to a local transaction
await _ServiceListContext.SaveChangesAsync();
await _eventLogService.SaveEventAsync(evt, _ServiceListContext.Database.CurrentTransaction);
});
}
