private static StatefulApplyMethods CreateApplyMethods(Type type)
{
var allMethods = type.GetMethods(BindingFlags.NonPublic | BindingFlags.Instance);
var methodsCalledApply = allMethods.Where(m => m.Name == ApplyMethodsName);
var voidMethods = methodsCalledApply.Where(m => m.ReturnType == typeof(void));
var methodsAndParameters = voidMethods.Select(m => new { Method = m, Parameters = m.GetParameters() });
var withOneInputParameter = methodsAndParameters.Where(m => m.Parameters.Length == 1 && !m.Parameters[0].IsOut);
var methodAndEventType = withOneInputParameter.Select(m => new { m.Method, Type = m.Parameters[0].ParameterType });
var applyMethods = methodAndEventType.Where(m => m.Type.IsInterface && EventType.IsAssignableFrom(m.Type) && m.Type.Assembly != EventType.Assembly).ToArray();
// Verify no two methods could receive the same event type at the same time
var conflicting =
(from m1 in applyMethods
from m2 in applyMethods
where m1 != m2 && (m1.Type.IsAssignableFrom(m2.Type))
select new { OlderVersionType = m1.Type, NewerVersionType = m2.Type }).ToArray();
if (conflicting.Any())
{
throw new InvalidOperationException(string.Format("Aggregate {0} contains conflicting apply methods for different versions of the same event: {1}", type.FullName, string.Join(", ", conflicting.Select(c => string.Format("{0} --> {1}", c.NewerVersionType.FullName, c.OlderVersionType.FullName)))));
}
var actionDictionary = applyMethods
.ToDictionary(m => m.Type, m => CreateActionFromMethod(type, m.Type, m.Method));
var result = new StatefulApplyMethods(actionDictionary);
return(result);
}
protected StatefulAggregate()
{
_applyMethods = GetApplyMethods(this.GetType());
}
