/// <summary>
/// Gets a valid transition based on the event.
/// </summary>
/// <param name="transitionEvent">The transition event.</param>
/// <returns>The transition object.</returns>
private StateTransition GetValidTransition(StateTransitionEvent transitionEvent)
{
var transitions = this.StateTransitions.Where(t => t.Start == this.CurrentState && t.AllowedEvents.HasFlag(transitionEvent)).ToList();
if (transitions == null || transitions.Count() != 1)
{
throw new NotSupportedException(string.Format("The requested (current state = {0}, event = {1}) operation is not supported.", this.CurrentState, transitionEvent));
}
var transition = transitions[0];
return(transition);
}
/// <summary>
/// Moves to the next state asynchronously.
/// </summary>
/// <typeparam name="TResult">The type of the result object.</typeparam>
/// <param name="entitySet">The target entity set.</param>
/// <param name="action">The action name.</param>
/// <param name="method">The method to be executed.</param>
/// <param name="isRequestOffline">The flag indicating whether the current request is offline request.</param>
/// <returns>The result object.</returns>
private async Task <TResult> MoveNextAsync <TResult>(string entitySet, string action, Func <IContext, Task <TResult> > method, bool isRequestOffline)
{
StateTransitionEvent transitionEvent = await this.GetEventForRequestAsync(action, isRequestOffline);
var transition = this.GetValidTransition(transitionEvent);
switch (transition.Action)
{
case StateTransitionAction.ExecuteOnlineFirstIfFailedSwitchToOffline:
return(await ExecuteOnlineIfFailedTriggerOfflineRequestAsync(entitySet, action, method, transition.Stop));
case StateTransitionAction.ExecuteOnlineAndOffline:
return(await ExecuteBothOnlineAndOfflineAsync(method, transition.Stop));
case StateTransitionAction.ExecuteOnlineOnly:
return(await ExecuteOnlineAsync(method, transition.Stop));
case StateTransitionAction.ExecuteOfflineOnly:
return(await ExecuteOfflineAsync(method, transition.Stop));
case StateTransitionAction.SwitchToOffline:
return(await SwitchToOfflineAndExecuteAsync(action, method, transition.Stop));
case StateTransitionAction.SwitchToOnline:
return(await SwitchToOnlineAndExecuteIfFailedTriggerOfflineRequestAsync(entitySet, action, method, transition.Stop));
case StateTransitionAction.ChangeState:
return(await Task.Run <TResult>(() =>
{
SetState(transition.Stop);
return null;
}));
default:
throw new NotSupportedException("Unsupported transition action.");
}
}
/// <summary>
/// Moves to the next state asynchronously.
/// </summary>
/// <param name="transitionEvent">The transition event.</param>
/// <returns>No return.</returns>
private async Task MoveNextAsync(StateTransitionEvent transitionEvent)
{
var transition = this.GetValidTransition(transitionEvent);
switch (transition.Action)
{
case StateTransitionAction.SwitchToOffline:
await this.SwitchToOfflineAsync(transition.Stop);
break;
case StateTransitionAction.SwitchToOnline:
await this.SwitchToOnlineAsync(transition.Stop);
break;
case StateTransitionAction.ChangeState:
this.SetState(transition.Stop);
break;
default:
throw new NotSupportedException("Unsupported transition action.");
}
}
public StateTransition(ChainedContextState start, ChainedContextState stop, StateTransitionEvent allowedEvents, StateTransitionAction action)
{
this.Start = start;
this.Stop = stop;
this.AllowedEvents = allowedEvents;
this.Action = action;
}