public DispatcherMessageMatcher(DispatcherMessage message)
{
if (message == null)
{
throw new ArgumentNullException("message");
}
_message = message;
}
public AppDispatcher()
{
_callbacks = new Dictionary <DispatchToken, Action <DispatcherMessage> >();
_executingCallbacks = new HashSet <DispatchToken>();
_finishedCallbacks = new HashSet <DispatchToken>();
_isDispatching = false;
_currentMessage = null;
}
#pragma warning disable CS0618 // Type or member is obsolete
private void Dispatch(DispatcherMessage message)
#pragma warning restore CS0618 // Type or member is obsolete
{
if (message == null)
{
throw new ArgumentNullException(nameof(message));
}
if (_isDispatching)
{
throw new InvalidOperationException("Cannot dispatch while already dispatching");
}
_isDispatching = true;
_currentMessage = message;
_executingCallbacks.Clear();
_finishedCallbacks.Clear();
try
{
foreach (var callback in _callbacks)
{
// Skip over callbacks that have already been called (by an earlier callback that used WaitFor)
if (_finishedCallbacks.Contains(callback.Key))
{
continue;
}
_executingCallbacks.Add(callback.Key);
callback.Value(_currentMessage);
_executingCallbacks.Remove(callback.Key);
_finishedCallbacks.Add(callback.Key);
}
}
finally
{
_isDispatching = false;
_currentMessage = null;
_executingCallbacks.Clear();
_finishedCallbacks.Clear();
}
}
private void Dispatch(DispatcherMessage message)
{
if (message == null)
throw new ArgumentNullException("message");
// Dispatching a message during the handling of another is not allowed, in order to be consistent with the Facebook Dispatcher
// (see https://github.com/facebook/flux/blob/master/src/Dispatcher.js#L183)
if (_dispatcher != null)
{
if (_currentDispatching)
throw new Exception("Cannot dispatch in the middle of a dispatch.");
_currentDispatching = true;
try
{
_dispatcher(message);
}
finally
{
_currentDispatching = false;
}
}
}
/// <summary>
/// This will execute the specified callback with a non-null reference if the current DispatcherMessage action matches type T and
/// if that instance of T meets the specified conditions. It will never call the work action with a null reference and it will never
/// return a null reference. It will throw an exception for a null DispatcherMessage, null condition or null work reference.
/// </summary>
public static IMatchDispatcherMessages If <T>(this DispatcherMessage message, Func <T, bool> condition, Action <T> work) where T : class, IDispatcherAction
{
return(new DispatcherMessageMatcher(message).Else(condition, work));
}
/// <summary>
/// This will execute the specified callback with a non-null reference if the current DispatcherMessage action matches type T.
/// It will never call the work action with a null reference and it will never return a null reference. It will throw an exception
/// for a null DispatcherMessage or null work reference.
/// </summary>
public static IMatchDispatcherMessages If <T>(this DispatcherMessage message, Action <T> work) where T : class, IDispatcherAction
{
return(new DispatcherMessageMatcher(message).Else(work));
}