private async void PreviousQuestion()
{
var properties = new Dictionary <string, string>
{
{ "CurrentQuestionID", CurrentQuestion?.QuestionID.ToString() },
};
DependencyService.Get <IMetricsManagerService>().TrackEvent("SurveyPreviousQuestion", properties, null);
// Save the response
await _response.SaveAsync();
// If the survey is ended, set the question to the last answered question
int?previousId;
if (_isSurveyEnded)
{
IsSurveyEnded = false;
previousId = _response.Item.QuestionResponses.Max(q => q.QuestionID);
}
else
{
// Otherwise, set the question to the question with the next lowest question number
previousId = PreviousQuestion(CurrentQuestion.QuestionNum);
}
// If the question identifier cannot be found, set to the first question (should not happen)
_index = QuestionIndex(previousId) ?? FirstQuestionIndex();
UpdateCommands();
QuestionChanged?.Invoke(this, new EventArgs());
}
private async void NextQuestion()
{
// Add empty answers if necessary
var questionResponse = _response.Item.QuestionResponses.FirstOrDefault(r => r.QuestionID == CurrentQuestion?.QuestionID);
if (questionResponse == null)
{
_response.Item.QuestionResponses.Add(new SurveyQuestionResponseModel
{
QuestionID = CurrentQuestion.QuestionID,
});
}
// Check if we should prompt in case the user did not fill out the additional information field
var shouldPrompt = false;
var questionAnswers = CurrentQuestion.AnswerChoices.ToDictionary(a => a.AnswerChoiceID, a => a);
foreach (var answer in CurrentAnswers)
{
if (string.IsNullOrEmpty(answer.AdditionalAnswerData))
{
SurveyQuestionAnswerChoiceModel questionAnswer;
if (questionAnswers.TryGetValue(answer.AnswerChoiceID, out questionAnswer) && questionAnswer.AdditionalAnswerDataFormat != AnswerFormat.None)
{
shouldPrompt = true;
break;
}
}
}
// Prompt the user if any additional information entries are empty
if (shouldPrompt)
{
var shouldContinue = await App.DisplayAlertAsync(
"Incomplete Answer",
"At least one answer requires more information, are you sure you want to continue?",
"Yes",
"No");
if (!shouldContinue)
{
return;
}
}
var properties = new Dictionary <string, string>
{
{ "CurrentQuestionID", CurrentQuestion?.QuestionID.ToString() },
};
DependencyService.Get <IMetricsManagerService>().TrackEvent("SurveyNextQuestion", properties, null);
// Save the response
await _response.SaveAsync();
// Create a lookup table for all the currently selected answers
var currentAnswerIds = new HashSet <int>(CurrentAnswers.Select(a => a.AnswerChoiceID));
// Get a reference to any matching question answer model from the survey question
var matchingAnswer = CurrentQuestion.AnswerChoices.FirstOrDefault(a => currentAnswerIds.Contains(a.AnswerChoiceID));
// Set the next question to the next question identifier from the question answer model if available;
// otherwise, set the next question to the next highest question number
var nextQuestionIndex = QuestionIndex(matchingAnswer?.NextQuestionID) ?? NextQuestion(CurrentQuestion.QuestionNum);
_index = nextQuestionIndex ?? _index + 1;
// End the survey if the matching question answer disqualifies the survey, or if there are no more questions
if ((matchingAnswer?.EndSurvey ?? false) || nextQuestionIndex == null)
{
EndSurvey();
}
UpdateCommands();
QuestionChanged?.Invoke(this, new EventArgs());
}