public static ICommandHandlerBuilder <TCommand> UseValidator <TCommand>(
this ICommandHandlerBuilder <TCommand> builder, IValidator <TCommand> validator)
{
return(builder.Pipe(next => async(message, ct) =>
{
await validator.ValidateAndThrowAsync(message.Body, cancellationToken: ct);
await next(message, ct);
}));
}
internal static ICommandHandlerBuilder <CommandMessage <TMessage> > Validate <TMessage>(
this ICommandHandlerBuilder <CommandMessage <TMessage> > commandHandlerBuilder,
Func <TMessage, ValidationResult> validator)
{
return(commandHandlerBuilder.Pipe(next => (commandMessage, ct) =>
{
validator(commandMessage.Command);
return next(commandMessage, ct);
}));
}
/// <summary>
/// Handles the message and is the last stage in a handler pipeline.
/// </summary>
/// <param name="handlerBuilder">The <see cref="ICommandHandlerBuilder{TMessage}"/>instance.</param>
/// <param name="handler">The handler.</param>
public static void Handle <TMessage>(
this ICommandHandlerBuilder <TMessage> handlerBuilder,
HandlerSync <TMessage> handler)
where TMessage : class
{
handlerBuilder.Handle((message, _) =>
{
handler(message);
return(Task.FromResult(0));
});
}
// 3. Example pipeline that ensures the user is authorized by
// checking their role.
internal static ICommandHandlerBuilder <CommandMessage <TMessage> > RequireRole <TMessage>(
this ICommandHandlerBuilder <CommandMessage <TMessage> > commandHandlerBuilder,
string role)
{
return(commandHandlerBuilder.Pipe(next => (commandMessage, ct) =>
{
if (!commandMessage.GetUser().IsInRole(role))
{
throw new InvalidOperationException("Not Authorized");
}
return next(commandMessage, ct);
}));
}
public static ICommandHandlerBuilder <IRoadRegistryContext, TCommand> UseRoadRegistryContext <TCommand>(
this ICommandHandlerBuilder <TCommand> builder, IStreamStore store, IRoadNetworkSnapshotReader snapshotReader, EventEnricher enricher)
{
if (store == null)
{
throw new ArgumentNullException(nameof(store));
}
if (snapshotReader == null)
{
throw new ArgumentNullException(nameof(snapshotReader));
}
if (enricher == null)
{
throw new ArgumentNullException(nameof(enricher));
}
return(builder.Pipe <IRoadRegistryContext>(next => async(message, ct) =>
{
var map = new EventSourcedEntityMap();
var context = new RoadRegistryContext(map, store, snapshotReader, SerializerSettings, EventMapping);
await next(context, message, ct);
foreach (var entry in map.Entries)
{
var events = entry.Entity.TakeEvents();
if (events.Length != 0)
{
var messageId = message.MessageId.ToString("N");
var version = entry.ExpectedVersion;
Array.ForEach(events, @event => enricher(@event));
var messages = Array.ConvertAll(
events,
@event =>
new NewStreamMessage(
Deterministic.Create(Deterministic.Namespaces.Events,
$"{messageId}-{version++}"),
EventMapping.GetEventName(@event.GetType()),
JsonConvert.SerializeObject(@event, SerializerSettings)
));
await store.AppendToStream(entry.Stream, entry.ExpectedVersion, messages, ct);
}
}
}
));
}
public static ICommandHandlerBuilder <CommandMessage <TCommand> > AddSqlStreamStore <TCommand>(
this ICommandHandlerBuilder <CommandMessage <TCommand> > commandHandlerBuilder,
Func <IStreamStore> getStreamStore,
Func <ConcurrentUnitOfWork> getUnitOfWork,
EventMapping eventMapping,
EventSerializer eventSerializer)
{
return(commandHandlerBuilder.Pipe(next => async(commandMessage, ct) =>
{
await next(commandMessage, ct);
return await AddSqlStreamStore(
getStreamStore,
getUnitOfWork,
eventMapping,
eventSerializer,
commandMessage,
ct);
}));
}
public static ICommandHandlerBuilder <T> Log <T>(this ICommandHandlerBuilder <T> builder,
ILoggerFactory?loggerFactory = null) where T : class
{
var log = loggerFactory?.CreateLogger <T>() ?? new NullLogger <T>();
return(builder.Pipe(next => async(m, ct) => {
if (log.IsEnabled(LogLevel.Information))
{
log.LogInformation(m.ToString());
}
try {
return await next(m, ct);
} catch (Exception ex) {
if (log.IsEnabled(LogLevel.Error))
{
log.LogError(ex.ToString());
}
throw;
}
}));
}
this ICommandHandlerBuilder <TCommand> builder, EventStoreClient eventStore, IMessageTypeMapper messageTypeMapper, JsonSerializerOptions eventSerializerOptions, ICommandContext?commandContext = null)
public static ICommandHandlerBuilder <CommandMessage <TMessage> > RequiresRole <TMessage>(this ICommandHandlerBuilder <CommandMessage <TMessage> > source, string roleName)
where TMessage : class
{
return(source.Pipe(next => async(message, ct) =>
{
var metadata = CommandMetaData.FromDictionary(message.Metadata);
if (metadata.HasRole(roleName))
{
return await next(message, ct);
}
throw new InsufficientRights();
}));
}
