/// <summary>
/// Executes the default behavior for saving an aswer.
/// </summary>
/// <param name="savedAnswer"></param>
/// <param name="answer"></param>
/// <param name="repository"></param>
/// <param name="question"></param>
/// <param name="insert"></param>
/// <param name="update"></param>
private void SaveAnswer(Answer savedAnswer, AnswerModelViewBase answer, IRepository repository, Domain.Question question, Func <IRepository, AnswerQuestionOption> insert, Func <IRepository, AnswerQuestionOption, bool> update)
{
// If it came until here, we know that it is likely to be a valid request
savedAnswer.AnsweredAt = DateTime.Now; //Changing to know the last time the user answered
// Loading the last option that the user selected
AnswerQuestionOption answerOption = null;
if (savedAnswer.Answers != null)
{
answerOption = savedAnswer.Answers.FirstOrDefault(r => r.Question.Id == answer.Question.Id);
}
else
{
savedAnswer.Answers = new List <AnswerQuestionOption>();
}
// If it is null, means that the user have not answered the question yet
if (answerOption == null)
{
answerOption = insert(repository);
answerOption.Question = question;
savedAnswer.Answers.Add(answerOption);
}
else
{
update(repository, answerOption);
}
repository.SaveChanges();
}
/// <summary>
/// Implements the default behavior for saving an answer, such as checking
/// the ownership of that quiz, identifying the parameters and etc.
/// At the end of the execution, this method will delegate the operation to
/// one of the functions sent as parameter, depending on the results encontered here.
/// </summary>
/// <param name="answer">The answer to be persisted</param>
/// <param name="insert">The instructions for including a new value</param>
/// <param name="update">The instructions for updating a item that is already in the database</param>
/// <returns></returns>
protected ResultOperation SaveAnswer(AnswerModelViewBase answer,
Func <IRepository, AnswerQuestionOption> insert,
Func <IRepository, AnswerQuestionOption, bool> update)
{
try
{
// Disposing repository to avoid overloading the data context
using (IRepository repository = Repository.Repository.CreateRepository())
{
// Loading the quiz from the database
Domain.Quiz quiz = repository.GetQuiz(answer.Question.IdQuiz);
// Loading the answer for that qu iz and for that user
Domain.Answer savedAnswer = repository.GetAnswer(quiz.Id, userId);
if (savedAnswer.Id == answer.Id)
{
// If there is no answer, it might mean that someone is trying to send bad data.
// We also will allow only changes to quizes that are open and have not been evaluated
if (savedAnswer != null && savedAnswer.IsOpen && !savedAnswer.Evaluated)
{
// Making sure that the question received belongs to that quiz
var question = quiz.Questions.FirstOrDefault(r => r.Id == answer.Question.Id);
if (question != null)
{
SaveAnswer(savedAnswer, answer, repository, question, insert, update);
}
}
else
{
messages.Add("There is no quiz active for this question!");
}
}
else
{
messages.Add("There is no quiz active for this question!");
}
}
}
catch (Exception ex)
{
LogException(ex);
messages.Add(DefaultErrorMessage());
}
return(messages);
}
/// <summary>
/// Auxiliar method for getting the persisted answer for a quiz application and determined question.
/// </summary>
/// <param name="repository"></param>
/// <param name="answer"></param>
/// <param name="idQuestion"></param>
/// <returns></returns>
private AnswerModelViewBase CreateInfoAnswer(IRepository repository,
Answer answer, int idQuestion)
{
AnswerQuestionOption infoAnswer = repository.GetAnswerQuestionOptionByQuestioId(answer.Id, idQuestion);
if (infoAnswer != null)
{
AnswerModelViewBase returnAnswer = CreateAnswerModelView(repository, answer, idQuestion, infoAnswer);
if (returnAnswer != null)
{
returnAnswer.Id = infoAnswer.Id;
return(returnAnswer);
}
}
return(null);
}
/// <summary>
/// Create the specific AnswerView based on the question type.
/// Can return a TrueFalseAnswerview, MultipleChoiceAnswerView or OpenEndedAnswerView
/// </summary>
/// <param name="repository"></param>
/// <param name="answer"></param>
/// <param name="idQuestion"></param>
/// <param name="infoAnswer"></param>
/// <returns></returns>
private AnswerModelViewBase CreateAnswerModelView(IRepository repository,
Answer answer, int idQuestion, Domain.AnswerQuestionOption infoAnswer)
{
AnswerModelViewBase returnAnswer = null;
switch (repository.GetQuestion(idQuestion).QuestionType)
{
case QuestionType.TrueFalse_Question:
returnAnswer = new TrueFalseAnswerView()
{
Option = (infoAnswer as TrueFalseAnswer).Choice
};
break;
case QuestionType.Multiple_Choice:
returnAnswer = new MultipleChoiceAnswerView()
{
IdAnswers = new List <int>()
};
foreach (var item in repository.GetMultipleChoiceAnswer(answer.Id, idQuestion).MultipleChoice_Choices)
{
(returnAnswer as MultipleChoiceAnswerView).IdAnswers.Add(item.IdChoice);
}
break;
case QuestionType.Open_Ended:
returnAnswer = new OpenEndedAnswerView()
{
Content = (infoAnswer as OpenEnded).Response
};
break;
}
return(returnAnswer);
}
