/// <summary>
/// Register query async handler.
/// </summary>
/// <typeparam name="TQuery">Type of query to be handled.</typeparam>
/// <typeparam name="TResult">Type of query's result.</typeparam>
/// <param name="queryAsyncHandlerFactory">Factory which will provide an instance of a query handler that handles the specified <typeparamref name="TQuery"/> query.</param>
public void Register <TQuery, TResult>(Func <IQueryAsyncHandler <TQuery, TResult> > queryAsyncHandlerFactory) where TQuery : class, IQuery <TResult>
{
if (queryAsyncHandlerFactory == null)
{
throw new ArgumentNullException(nameof(queryAsyncHandlerFactory));
}
Type queryType = typeof(TQuery);
QueryHandlerDelegate <TResult> handleQueryDelegate;
if (_queryHandlerDelegatesByQueryType.TryGetValue(queryType, out handleQueryDelegate))
{
throw new InvalidOperationException($"Duplicate query handler registered for {queryType.Name}.");
}
QueryHandlerDelegate <TResult> newHandleQueryDelegate = QueryHandlerDelegateBuilder.FromFactory(queryAsyncHandlerFactory);
_queryHandlerDelegatesByQueryType.Add(queryType, newHandleQueryDelegate);
}
