private async Task DeleteActivityInternal(ConversationReference cr,
IEnumerable <DeleteActivityHandler> updateHandlers,
Func <Task> callAtBottom)
{
BotAssertSlack.ConversationReferenceNotNull(cr);
if (updateHandlers == null)
{
throw new ArgumentException(nameof(updateHandlers));
}
if (updateHandlers.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 <DeleteActivityHandler> remaining = updateHandlers.Skip(1);
await DeleteActivityInternal(cr, remaining, callAtBottom).ConfigureAwait(false);
}
// Grab the current middleware, which is the 1st element in the array, and execute it.
DeleteActivityHandler toCall = updateHandlers.First();
await toCall(this, cr, next);
}
/// <summary>
/// Creates a conversation reference from an activity.
/// </summary>
/// <param name="activity">The activity.</param>
/// <returns>A conversation reference for the conversation that contains the activity.</returns>
/// <exception cref="ArgumentNullException">
/// <paramref name="activity"/> is <c>null</c>.</exception>
public static ConversationReference GetConversationReference(Activity activity)
{
BotAssertSlack.ActivityNotNull(activity);
ConversationReference r = new ConversationReference
{
ActivityId = activity.Id,
User = activity.From,
Bot = activity.Recipient,
Conversation = activity.Conversation,
ChannelId = activity.ChannelId,
ServiceUrl = activity.ServiceUrl
};
return(r);
}
/// <summary>
/// Starts activity processing for the current bot turn.
/// </summary>
/// <param name="context">The turn's context object.</param>
/// <param name="callback">A callback method to run at the end of the pipeline.</param>
/// <param name="cancelToken">A cancellation token for the task.</param>
/// <returns>A task that represents the work queued to execute.</returns>
/// <exception cref="ArgumentNullException">
/// <paramref name="context"/> is null.</exception>
/// <remarks>The adapter calls middleware in the order in which you added it.
/// The adapter passes in the context object for the turn and a next delegate,
/// and the middleware calls the delegate to pass control to the next middleware
/// in the pipeline. Once control reaches the end of the pipeline, the adapter calls
/// the <paramref name="callback"/> method. If a middleware component doesn’t call
/// the next delegate, the adapter does not call any of the subsequent middleware’s
/// <see cref="IMiddleware.OnTurn(ITurnContext, MiddlewareSet.NextDelegate)"/>
/// methods or the callback method, and the pipeline short circuits.
/// <para>When the turn is initiated by a user activity (reactive messaging), the
/// callback method will be a reference to the bot's
/// <see cref="IBot.OnTurn(ITurnContext)"/> method. When the turn is
/// initiated by a call to <see cref="ContinueConversation(ConversationReference, Func{ITurnContext, Task})"/>
/// (proactive messaging), the callback method is the callback method that was provided in the call.</para>
/// </remarks>
protected async Task RunPipeline(ITurnContext context, Func <ITurnContext, Task> callback = null, CancellationTokenSource cancelToken = null)
{
BotAssertSlack.ContextNotNull(context);
// Call any registered Middleware Components looking for ReceiveActivity()
if (context.Activity != null)
{
await _middlewareSet.ReceiveActivityWithStatus(context, callback).ConfigureAwait(false);
}
else
{
// call back to caller on proactive case
if (callback != null)
{
await callback(context).ConfigureAwait(false);
}
}
}
public MiddlewareSetSlack Use(IMiddlewareSlack middleware)
{
BotAssertSlack.MiddlewareNotNull(middleware);
_middleware.Add(middleware);
return(this);
}