/**
* @desc Checks if PG code is acceptable.
* @param string $code The PG Code.
* @throws Exception If there is an error with the PG code.
* @return object Information on the question.
*/
public function CodeCheck($code)
{
$haserrors = false;
$haswarnings = false;
$client = WebworkClient::Get();
$env = WebworkQuestion::DefaultEnvironment();
$result = $client->renderProblem($env, $code);
if (isset($result->errors) && $result->errors != '' && $result->errors != null) {
$haserrors = true;
}
if (isset($result->warnings) && $result->warnings != '' && $result->warnings != null) {
$haswarnings = true;
}
//Validity Check
if ($haserrors == false && $haswarnings == false) {
$output = new stdClass();
$output->grading = $result->grading;
$derivation = new stdClass();
$derivation->html = $result->output;
$derivation->seed = $result->seed;
$output->derivation = $derivation;
} else {
//NOW WE ARE INVALID going to throw
$msg = "<h2>PG Code Problems</h2>";
if ($haserrors) {
$msg .= "<h3>Errors</h3>";
$msg .= $result->errors;
}
if ($haswarnings) {
$msg .= "<h3>Warnings</h3>";
$msg .= $result->warnings;
}
throw new Exception($msg);
}
return $output;
}
/**
* @desc Grades a particular question state.
* @param object $state The state to grade.
* @return true.
*/
public function grade(&$state)
{
$seed = $state->responses['seed'];
$answers = array();
if (isset($state->responses['answers']) && is_array($state->responses['answers'])) {
foreach ($state->responses['answers'] as $answerobj) {
if (is_string($answerobj->field) && is_string($answerobj->answer)) {
array_push($answers, array('field' => $answerobj->field, 'answer' => $answerobj->answer));
}
}
}
if (isset($state->responses) && is_array($state->responses)) {
foreach ($state->responses as $key => $value) {
if (is_string($key) && is_string($value)) {
array_push($answers, array('field' => $key, 'answer' => $value));
}
}
}
//combine results from the answer array for checkboxes
$checkanswers = array();
$tempanswers = array();
for ($i = 0; $i < count($answers); $i++) {
$fieldname = $answers[$i]['field'];
$pos = strpos($fieldname, '_');
if ($pos !== FALSE) {
$fieldname = substr($fieldname, 0, $pos);
if (isset($checkanswers[$fieldname])) {
$checkanswers[$fieldname] .= $answers[$i]['answer'];
} else {
$checkanswers[$fieldname] = $answers[$i]['answer'];
}
} else {
array_push($tempanswers, $answers[$i]);
}
}
foreach ($checkanswers as $key => $value) {
array_push($tempanswers, array('field' => $key, 'answer' => $value));
}
$answers = $tempanswers;
//base64 encoding
for ($i = 0; $i < count($answers); $i++) {
$answers[$i]['field'] = base64_encode($answers[$i]['field']);
$answers[$i]['answer'] = base64_encode($answers[$i]['answer']);
}
$client = WebworkClient::Get();
$env = WebworkQuestion::DefaultEnvironment();
$env->problemSeed = $seed;
$results = $client->renderProblemAndCheck($env, $this->_data->code, $answers);
//process the question
$question = $results->problem;
$derivation = new stdClass();
$derivation->seed = $question->seed;
$derivation->html = base64_decode($question->output);
$this->_derivation = $derivation;
//assign a grade
$answers = $results->answers;
$state->raw_grade = $this->processAnswers($answers);
// mark the state as graded
$state->event = $state->event == QUESTION_EVENTCLOSE ? QUESTION_EVENTCLOSEANDGRADE : QUESTION_EVENTGRADE;
//put the responses into the state to remember
if (!is_array($state->responses)) {
$state->responses = array();
}
$state->responses['answers'] = $answers;
return true;
}