function _quiz_question_get_instance in Quiz 8.4

Same name and namespace in other branches

1. 6.6 question_types/quiz_question/quiz_question.module \_quiz_question_get_instance()
2. 6.3 question_types/quiz_question/quiz_question.module \_quiz_question_get_instance()
3. 6.4 question_types/quiz_question/quiz_question.module \_quiz_question_get_instance()
4. 6.5 question_types/quiz_question/quiz_question.module \_quiz_question_get_instance()
5. 7.6 question_types/quiz_question/quiz_question.module \_quiz_question_get_instance()
6. 7 question_types/quiz_question/quiz_question.module \_quiz_question_get_instance()
7. 7.4 question_types/quiz_question/quiz_question.module \_quiz_question_get_instance()
8. 7.5 question_types/quiz_question/quiz_question.module \_quiz_question_get_instance()

Get an instance of a quiz question.

Get information about the class and use it to construct a new object of the appropriate type.

Parameters

$node: Question node

$use_cached: Can we use a cached version of the node?

Return value

The appropriate QuizQuestion extension instance

4 calls to _quiz_question_get_instance()

quiz_question_answering_form in question_types/quiz_question/quiz_question.module

Get the form to show to the quiz taker.

quiz_question_form_node_form_alter in question_types/quiz_question/quiz_question.module

Implements hook_form_BASE_FORM_ID_alter().

quiz_question_has_been_answered in question_types/quiz_question/quiz_question.module

@todo Please document this function.

quiz_question_quiz_question_score in question_types/quiz_question/quiz_question.module

Implements hook_quiz_question_score().

File

question_types/quiz_question/quiz_question.module, line 694

Quiz Question module. This module provides the basic facilities for adding quiz question types to a quiz.

Code

function _quiz_question_get_instance($node, $use_cached = FALSE) {

  // We use static caching to improve performance
  static $question_instances = array();
  $using_dummy_node = FALSE;
  if (is_object($node) && !$node instanceof \stdClass) {
    $vid = $node
      ->getRevisionId() ? $node
      ->getRevisionId() : 0;
    if ($use_cached && isset($question_instances[$vid])) {

      // We just return a cached instance of the QuizQuestion
      return $question_instances[$vid];
    }
    $name = $node
      ->getType();
  }
  elseif (is_object($node) && $node instanceof \stdClass) {
    $vid = $node->vid ? $node->vid : 0;
    if ($use_cached && isset($question_instances[$vid])) {

      // We just return a cached instance of the QuizQuestion
      return $question_instances[$vid];
    }

    // If $node don't have a type it is a dummy node
    if (!isset($node->type) || !($name = $node->type)) {

      // To substanitally improve performance(especially on the result page) we avoid node_load()...
      $sql = 'SELECT d.type, r.nid, r.vid, r.title, p.max_score
              FROM {node_field_revision} r
              JOIN {node} n ON r.nid = n.nid
              JOIN {node_field_data} d ON d.nid = n.nid
              JOIN {quiz_question_properties} p ON r.vid = p.vid
              WHERE r.vid = :vid';
      $node = db_query($sql, array(
        ':vid' => $node->vid,
      ))
        ->fetch();

      // @todo: Do it in proper way.
      $node = (array) $node;
      $node = entity_create('node', $node);
      $name = $node
        ->getType();
      $using_dummy_node = TRUE;
    }
  }
  elseif (is_array($node)) {
    $name = $node['type'];
    $vid = $node['vid'];
    if ($use_cached && isset($question_instances[$vid])) {

      // We return a cached instance of the appropriate QuizQuestion
      return $question_instances[$vid];
    }
  }

  // No cached instance of QuizQuestion has been returned. We construct a new instance
  $info = _quiz_question_get_implementations();
  $constructor = $info[$name]['question provider'];
  if (empty($constructor)) {
    return FALSE;
  }

  // We create a new instance of QuizQuestion
  $to_return = new $constructor($node);
  if (!$to_return instanceof Drupal\quiz_question\QuizQuestion) {

    // Make sure the constructor is creating an extension of QuizQuestion
    drupal_set_message(t('The question-type %name isn\'t a QuizQuestion. It needs to extend the QuizQuestion class.', array(
      '%name' => $name,
    )), 'error', FALSE);
  }

  // If we're using a dummy node we have to run getNodeProperties, and populate the node with those properties
  if ($using_dummy_node) {
    $props = $to_return
      ->getNodeProperties();
    foreach ($props as $key => $value) {
      $to_return->node->{$key} = $value;
    }
  }

  // Cache the node
  $question_instances[$vid] = $to_return;
  return $to_return;
}