/// <summary>
/// Adds a response handler for send activity operations.
/// </summary>
/// <param name="handler">The handler to add to the context object.</param>
/// <returns>The updated context object.</returns>
/// <exception cref="ArgumentNullException"><paramref name="handler"/> is <c>null</c>.</exception>
/// <remarks>When the context's <see cref="SendActivityAsync(IActivity, CancellationToken)"/>
/// or <see cref="SendActivitiesAsync(IActivity[], CancellationToken)"/> methods are called,
/// the adapter calls the registered handlers in the order in which they were
/// added to the context object.
/// </remarks>
public ITurnContext OnSendActivities(SendActivitiesHandler handler)
{
if (handler == null)
{
throw new ArgumentNullException(nameof(handler));
}
_onSendActivities.Add(handler);
return(this);
}
private async Task SendActivitiesInternal(
List <Activity> activities,
IEnumerable <SendActivitiesHandler> sendHandlers,
Func <Task> callAtBottom)
{
if (activities == null)
{
throw new ArgumentException(nameof(activities));
}
if (sendHandlers == null)
{
throw new ArgumentException(nameof(sendHandlers));
}
if (sendHandlers.Count() == 0) // No middleware to run.
{
if (callAtBottom != null)
{
await callAtBottom();
}
return;
}
// Default to "No more Middleware after this".
async Task next()
{
// Remove the first item from the list of middleware to call,
// so that the next call just has the remaining items to worry about.
IEnumerable <SendActivitiesHandler> remaining = sendHandlers.Skip(1);
await SendActivitiesInternal(activities, remaining, callAtBottom).ConfigureAwait(false);
}
// Grab the current middleware, which is the 1st element in the array, and execute it
SendActivitiesHandler caller = sendHandlers.First();
await caller(this, activities, next);
}
public ITurnContext OnSendActivities(SendActivitiesHandler handler)
{
return(_adapter.OnSendActivities(handler));
}
public ITurnContext OnSendActivities(SendActivitiesHandler handler) => _innerTurnContext.OnSendActivities(handler);
public ITurnContext OnSendActivities(SendActivitiesHandler handler)
{
throw new NotImplementedException();
}
public ITurnContext OnSendActivities(SendActivitiesHandler handler)
{
return(_innerTurnContext.OnSendActivities(handler));
}
