public static SingleSubscription SubscribeToEventOnceAsync <T>(Action <EventHandler <T> > subscribe,
Action <EventHandler <T> > unsubscribe,
EventHandler <T> callback)
where T : EventArgs
{
var result = new SingleSubscription();
var accessLock = new object();
var done = false;
EventHandler <T> handler = null;
handler = new EventHandler <T>(
(o, e) =>
{
//Ensure no concurrent invocations of the event, though I'm not sure if .net allows for that
lock (accessLock)
{
//Check if we're done calling the event once. If so, we don't want to invoke twice.
if (!done)
{
//We're now done. Set the flag so we aren't called again.
done = true;
//Invoke the user's code for the one-time event subscription
callback(o, e);
//Signal that the user's code is done running, so the SubscribeToEventOnce caller
//thread can be unblocked.
result.Signal();
//Yay closures
unsubscribe(handler);
}
}
}
);
//Subscribe to the event which we are trying to listen to once
subscribe(handler);
return(result);
}
public async Task <string> MakeSingleJobSubscription(User user, string phone, long jobApplicationId)
{
//To be done in the controller
try
{
decimal constantCharge = 100m;
if (!(await ConfirmPhoneNumberAsync(phone)))
{
return("Error confirming phone number");
}
if (!(await DebitPhoneAsync(phone, constantCharge)))
{
return("Transaction failed");
}
Subscription newEntry = new SingleSubscription
{
DateCreated = DateTime.Now,
DateModified = DateTime.Now,
SubscriptionType = Pitchme.Models.Enums.SubscriptionType.Single,
IsActive = true,
PhoneNumber = phone,
User = user,
Amount = constantCharge,
JobApplicationId = jobApplicationId
};
uow.jobSubscriptionRepository.Add(newEntry);
uow.Save();
return("Success");
}
catch (Exception ex)
{
//Log
return("Error saving subscription, please contact admin");
}
}