/// <summary>
/// Validate user Answer
/// </summary>
/// <param name="question">Question that user answered</param>
/// <param name="userAnswer">String representation of user answer</param>
/// <returns></returns>
private bool CheckAnswerIsCorrect(GeneratedQuestion question,
string userAnswer)
{
bool result = false;
if (string.IsNullOrWhiteSpace(userAnswer))
{
return(false);
}
if (question.QuestionType == 1)
{
int rightAnswer = int.Parse(userAnswer);
if (question.Answers[rightAnswer].IsCorrect)
{
result = true;
}
}
if (question.QuestionType == 2)
{
result = true;
var answerArray = userAnswer.Split(',');
for (int i = 0; i < question.Answers.Count; i++)
{
if (question.Answers[i].IsCorrect != answerArray.Contains(i.ToString()))
{
result = false;
}
}
}
if (question.QuestionType == 3)
{
foreach (var ans in question.Answers)
{
if (ans.Body == userAnswer)
{
result = true;
}
}
}
return(result);
}
public ActionResult Process(FormCollection collection)
{
// Geting session information
int sessionId = 0;
TestData testData = GetTestData(out sessionId);
// If test data is bad ending survey
if (testData == null)
{
return(RedirectToAction("End"));
}
// If bad question token (for example student are trying to answer question previously cached in browser) redirecting to Index (will show last generated question)
if (collection["QuestionToken"] != testData.GetQuestionHash())
{
return(RedirectToAction("Index"));
}
// Get previous question to check asnwer is correct
GeneratedQuestion question =
TemplateManager.Generate(testData.CurrentQuestionId,
testData.TestSeed);
// Remembering some nessasary data
testData.ItemsTaken++;
testData.TotalDifficultiesUsed += testData.CurrentQuestionDifficulty;
// Calculating the amount that will change the difficulty
double difficultyShift = 0.2 + (float)2 / testData.ItemsTaken;
// Checking answer is correct
bool answerIsCorrect = CheckAnswerIsCorrect(question, collection["Answers"]);
// Saving to question information about its own statistic
QuestionController.AddAttempt(testData.CurrentQuestionId, answerIsCorrect);
// Adding data to 'ResultGraph'
testData.AddPointToResultGraph(answerIsCorrect);
// TODO: Temperory method for statistics. (Re)move
testData.AddPointToRDF();
// Correcting difficulty
if (answerIsCorrect)
{
testData.TrueDifficultyLevel += difficultyShift;
if (testData.TrueDifficultyLevel > 10)
{
testData.TrueDifficultyLevel = 10;
}
testData.RightAnswersCount++;
}
else
{
testData.TrueDifficultyLevel -= difficultyShift;
if (testData.TrueDifficultyLevel < 1)
{
testData.TrueDifficultyLevel = 1;
}
}
// TODO: Make CONST optional. For the next programmers' generation
// Checking if measurement error lower than CONST
var error = testData.CalculateError();
var measure = testData.CalculateMeasure();
if (error <= 0.5)
{
testData.TestCompleted = true;
}
if (measure + error <= 1 || measure - error >= 10)
{
testData.TestCompleted = true;
}
//Check for test min length
// TODO: Add some behaviors. For the next programmers' generation. For example different options for different test types.
// If amount of taken question equals amount of total questions in test, mark test as completed.
if (testData.ItemsTaken >= testData.MaxAmountOfQuestions)
{
testData.TestCompleted = true;
}
// TODO: Add min length to test data
else if (testData.ItemsTaken < 10)
{
testData.TestCompleted = false;
}
// Selecting next question
Question selectedQuestion = GetQuestion(testData);
// Generates random seed, which helps to generate the same question from tamplate, if needed
testData.TestSeed = TemplateManager.GetRandomSeed();
// Remembering next question parameters
testData.CurrentQuestionDifficulty = selectedQuestion.Difficulty;
testData.CurrentQuestionId = selectedQuestion.ID;
// Saving test session
SetTestData(testData, sessionId);
// Continue test or end it depending on TestCompleted flag
return((testData.TestCompleted) ? RedirectToAction("End") : RedirectToAction("Index"));
}
/// <summary>
/// Returns GeneratedQuestion
/// </summary>
/// <param name = "templateId">Template id</param>
/// <param name = "seed">Random seed</param>
/// <returns></returns>
public static GeneratedQuestion Generate(int templateId, int seed)
{
var result = new GeneratedQuestion();
var rnd = new Random(seed);
// Get template from _db
Question question =
Db.Questions.FirstOrDefault(q => q.ID == templateId);
if (question == null)
{
throw new Exception("Template not found");
}
result.Body = question.Body;
result.QuestionType = 1;
result.Answers = new List <GeneratedAnswer>();
// Insert definitions to Body
int tagsLength = TagStartInsert.Length + TagEndInsert.Length;
for (int i = 0; i < result.Body.Length - tagsLength; i++)
{
if (result.Body.Substring(i, TagStartInsert.Length) !=
TagStartInsert)
{
continue;
}
// We found start insert tag
int tagStartInsertPosition = i;
int definitionNamePosition = i + TagStartInsert.Length;
for (i = definitionNamePosition;
i < result.Body.Length - TagEndInsert.Length;
i++)
{
if (result.Body.Substring(i, TagEndInsert.Length) !=
TagEndInsert)
{
continue;
}
// We found end insert tag
string definitionName =
result.Body.Substring(definitionNamePosition,
i - definitionNamePosition);
if (!string.IsNullOrEmpty(definitionName))
{
// Get definition from _db
Definition definition =
Db.Definitions.FirstOrDefault(
d => d.Name == definitionName);
if (definition != null)
{
// Get examples to definition from _db
List <Example> examples =
definition.Examples.Where(e => !e.IsAntiExample)
.ToList();
if (examples.Count == 0)
{
throw new Exception("Definition has no examples");
}
Example example =
examples[rnd.Next(0, examples.Count)];
// Replacing
string oldSubstr = TagStartInsert + definitionName +
TagEndInsert;
result.Body = result.Body.Replace(oldSubstr,
example.Value.Trim
());
i = tagStartInsertPosition + example.Value.Length -
1;
}
}
break;
}
}
// Get answers from _db
List <Answer> answers = question.Answers.ToList();
if (answers.Count == 0)
{
throw new Exception("Question has no answers");
}
foreach (Answer answer in answers)
{
var newAnswer = new GeneratedAnswer
{
Body = answer.Body,
IsCorrect = answer.IsCorrect
};
result.Answers.Add(newAnswer);
}
result.QuestionType = question.QuestionTypeID;
return(result);
}