/// <summary>
/// Append an event onto the event stream
/// </summary>
/// <param name="eventToAppend">
/// The event we want to write to the event stream
/// </param>
/// <param name="expectedTopSequence">
/// The sequence number we expect to be the last in the event stream - if events have been added since this then a
/// concurrency error is thrown
/// </param>
public async Task AppendEvent(object eventToAppend,
int?expectedTopSequence = null,
EventStreamExistenceConstraint streamConstraint = EventStreamExistenceConstraint.Loose)
{
if (null != _writer)
{
// make an event instance of this event and append it to the event stream
IAppendResult result = await _writer.AppendEvent(EventInstance.Wrap(eventToAppend),
expectedTopSequence.GetValueOrDefault(0),
streamConstraint : streamConstraint);
if (null != result)
{
if (null != this._notificationDispatcher)
{
if (result.NewEventStreamCreated)
{
await _notificationDispatcher.NewEntityCreated(this,
commentary : _context?.Commentary,
context : _context);
}
await _notificationDispatcher.NewEventAppended(this,
EventNameAttribute.GetEventName(eventToAppend.GetType()),
result.SequenceNumber,
commentary : _context?.Commentary,
eventPayload : eventToAppend,
context : _context);
}
}
}
}
public ProjectionBase()
{
// Wire up any explicit event handlers by dictionary
foreach (var interfaceImplementation in GetType().GetInterfaces())
{
if (interfaceImplementation.Name.StartsWith("IHandleEventType"))
{
Type eventArgumentType = interfaceImplementation.GetGenericArguments()[0];
string eventName = EventNameAttribute.GetEventName(eventArgumentType);
System.Reflection.MethodInfo miEvent = interfaceImplementation.GetMethods()[0];
// add these to our internal dicttionary
if (!typedEventHandlers.ContainsKey(eventName))
{
typedEventHandlers.Add(eventName, new Tuple <Type, System.Reflection.MethodInfo> (eventArgumentType, miEvent));
}
}
}
}