static void EnsureMappingToStartMessage(SagaCorrelator correlator, Type sagaType, IEnumerable <SagaMessage> associatedMessages)
{
Contract.Requires(correlator != null);
Contract.Requires(sagaType != null);
Contract.Requires(associatedMessages != null);
foreach (var message in associatedMessages.Where(message => message.StartsSaga))
{
var messageType = message.MessageType.GetTypeInfo();
var matches = from mapping in correlator.Mappings
where mapping.MessageType.GetTypeInfo().IsAssignableFrom(messageType)
select mapping;
if (!matches.Any())
{
throw new SagaConfigurationException(SR.UnmappedSagaStartMessage.FormatDefault(message.MessageType.Name, sagaType.Name));
}
}
}
static SagaToMessageMap EnsureSinglePropertyMapping(SagaCorrelator correlator, IEnumerable <SagaMessage> associatedMessages, Type sagaType)
{
Contract.Requires(correlator != null);
Contract.Requires(associatedMessages != null);
Contract.Requires(sagaType != null);
Contract.Ensures(Contract.Result <SagaToMessageMap>() != null);
var propertyMappings = (from message in associatedMessages
where message.StartsSaga
from mapping in correlator.Mappings
where mapping.MessageType == message.MessageType
group mapping by mapping.SagaDataProperty.Name).ToArray();
switch (propertyMappings.Length)
{
case 0:
throw new SagaConfigurationException(SR.SagaNotCorrelated);
case 1:
return(propertyMappings[0].First());
default:
var messageProperties = new StringBuilder();
var names = from mappings in propertyMappings
from mapping in mappings
select mapping.MessageProperty.Name;
using (var name = names.Distinct().Reverse().GetEnumerator())
{
name.MoveNext();
messageProperties.Append(SR.AndConjunction);
messageProperties.Append(name.Current);
while (name.MoveNext())
{
messageProperties.Insert(0, ", ");
messageProperties.Insert(0, name.Current);
}
}
throw new SagaConfigurationException(SR.TooManySagaCorrelationProperties.FormatDefault(sagaType.Name, messageProperties));
}
}
static void SetSearchMethodForMappings(
SagaCorrelator correlator,
Type sagaType,
Type sagaDataType,
IEnumerable <SagaMessage> associatedMessages,
ICollection <SagaSearchMethod> searchMethods)
{
Contract.Requires(correlator != null);
Contract.Requires(sagaType != null);
Contract.Requires(sagaDataType != null);
Contract.Requires(associatedMessages != null);
Contract.Requires(searchMethods != null);
foreach (var mapping in correlator.Mappings)
{
var messageType = mapping.MessageType.GetTypeInfo();
var associatedMessage = associatedMessages.FirstOrDefault(message => messageType.IsAssignableFrom(message.MessageType.GetTypeInfo()));
if (associatedMessage == null)
{
var interfaces = new[] { typeof(IStartWith <>), typeof(IStartWhen <>), typeof(IReceiveEvent <>), typeof(IHandleCommand <>) };
var interfaceNames = new StringBuilder();
using (var @interface = interfaces.Reverse().GetEnumerator())
{
@interface.MoveNext();
interfaceNames.Append(SR.OrConjunction);
interfaceNames.Append(@interface.Current.Name);
while (@interface.MoveNext())
{
interfaceNames.Insert(0, ", ");
interfaceNames.Insert(0, @interface.Current.Name);
}
}
throw new SagaConfigurationException(SR.UnhandledSagaMessage.FormatDefault(sagaType.Name, messageType.Name, interfaceNames));
}
SetSearchMethod(mapping, sagaDataType, searchMethods);
}
}
/// <summary>
/// Creates the metadata for a saga from the specified type.
/// </summary>
/// <param name="sagaType">The type of saga to create the metadata for.</param>
/// <returns>A new <see cref="SagaMetadata"/> instance.</returns>
/// <exception cref="ArgumentException"><paramref name="sagaType"/> is not a <see cref="ISaga{TData}"/>.</exception>
public static SagaMetadata Create(Type sagaType)
{
if (!sagaType.IsSaga())
{
throw new ArgumentException(SR.InvalidSaga.FormatDefault(sagaType.Name));
}
var sagaDataType = sagaType.GetSagaDataType();
var method = CorrelateOfT.MakeGenericMethod(sagaDataType);
var correlate = (Action <Type, ICorrelateSagaToMessage>)method.CreateDelegate(typeof(Action <Type, ICorrelateSagaToMessage>));
var correlator = new SagaCorrelator();
correlate(sagaType, correlator);
var associatedMessages = GetAssociatedMessages(sagaType).ToArray();
var mapping = EnsureSinglePropertyMapping(correlator, associatedMessages, sagaType);
var correlationProperty = mapping.SagaDataProperty;
var searchMethods = new List <SagaSearchMethod>();
SetSearchMethodForMappings(correlator, sagaType, sagaDataType, associatedMessages, searchMethods);
EnsureMappingToStartMessage(correlator, sagaType, associatedMessages);
return(new SagaMetadata(sagaType, sagaDataType, correlationProperty, associatedMessages, searchMethods));
}
protected override void CorrelateUsing(SagaCorrelator <TData> correlator)
{
Contract.Requires <ArgumentNullException>(correlator != null, nameof(correlator));
}
protected override void CorrelateUsing( SagaCorrelator<ProcurementData> correlator )
{
correlator.Correlate<SubmitPurchaseOrder>( command => command.AggregateId ).To( saga => saga.OrderId );
correlator.Correlate<SalesOrderReceived>( @event => @event.AggregateId ).To( saga => saga.OrderId );
correlator.Correlate<ShipmentReceived>( @event => @event.AggregateId ).To( saga => saga.OrderId );
}
