private GenericOperationResult <IEnumerable <Quiz> > GetPredefinedQuizes(User student)
{
GenericOperationResult <IEnumerable <Quiz> > result =
OperationResult.GetGenericResultObject <IEnumerable <Quiz> >();
try
{
// get all the tests information that the student has taken
var quizesStudentHasTaken = _studentQuizResultRepository.GetAllItems().ToList().Where(x => x.StudentId.Equals(student.UserID));
//get all the quizes
var allQuizes = _quizRepository.GetAllItems().Where(x => x.IsRandom == null || x.IsRandom == false);
//filter only non taken quizes
var takenQuizesIds = quizesStudentHasTaken.Select(x => x.QuizId).ToList();
var filteredQuizes = (from quiz in allQuizes let quizId = quiz.Id where !takenQuizesIds.Contains(quizId) select quiz).ToList();
//if everything goes well
result.SetData(filteredQuizes);
result.SetSuccess();
return(result);
}
catch (Exception e)
{
result.SetException();
result.AddExceptionMessage(e.Message);
}
return(result);
}
public bool CreateItem <T>(T item, ICrudRepository <T> repository, GenericOperationResult <T> or) where T : class, new()
{
if (item == null)
{
or.AddMessage(_localizedMessagesService.GetErrorMessage(ErrorMessageKeys.NullObjectReference));
or.SetFail();
return(false);
}
try
{
var success = repository.CreateItem(item);
if (success)
{
or.SetData(item);
return(true);
}
else
{
or.AddMessage(_localizedMessagesService.GetErrorMessage(ErrorMessageKeys.RepositoryError));
return(false);
}
}
catch (Exception e)
{
or.AddMessage(_localizedMessagesService.GetErrorMessage(ErrorMessageKeys.RepositoryError));
return(false);
}
}
public bool GetItems <T>(ICrudRepository <T> repository, GenericOperationResult <IEnumerable <T> > or)
{
try
{
var items = repository.GetAllItems();
or.SetData(items);
return(true);
}
catch (Exception e)
{
or.AddMessage(_localizedMessagesService.GetErrorMessage(ErrorMessageKeys.RepositoryError));
return(false);
}
}
public bool GetItem <T>(int id, ICrudRepository <T> repository, GenericOperationResult <T> or) where T : class, new()
{
if (id == 0)
{
or.AddMessage(_localizedMessagesService.GetErrorMessage(ErrorMessageKeys.InvalidId));
return(false);
}
try
{
var item = repository.GetItem(id);
or.SetData(item);
return(true);
}
catch (Exception e)
{
or.AddMessage(_localizedMessagesService.GetErrorMessage(ErrorMessageKeys.RepositoryError));
return(false);
}
}