abstract class QuizQuestion in Quiz 7.5

A base implementation of a quiz_question.

This class is adding a layer of abstraction between the node API, quiz API and the question types.

It is required that Question types extend this abstract class.

This class has default behaviour that all question types must have. It also handles the node API, but gives the question types opportunity to save, delete and provide data specific to the question types.

This abstract class also declares several abstract functions forcing question-types to implement required methods.

Hierarchy

• class \QuizQuestion

File

question_types/quiz_question/quiz_question.core.inc, line 42

Classes used in the Quiz Question module.

abstract class QuizQuestion {

  /*
   * QUESTION IMPLEMENTATION FUNCTIONS
   *
   * This part acts as a contract(/interface) between the question-types and the
   * rest of the system.
   *
   * Question types are made by extending these generic methods and abstract
   * methods.
   */

  /**
   * The current node for this question.
   */
  public $node = NULL;

  // Extra node properties.
  public $nodeProperties = NULL;

  /**
   * QuizQuestion constructor stores the node object.
   *
   * @param $node
   *   The node object
   */
  public function __construct(stdClass $node) {
    $this->node = $node;
  }

  /**
   * Allow question types to override the body field title.
   *
   * @return string
   *   The title for the body field.
   */
  public function getBodyFieldTitle() {
    return t('Question');
  }

  /**
   * Returns a node form to quiz_question_form.
   *
   * Adds default form elements, and fetches question type specific elements
   * from their implementation of getCreationForm.
   *
   * @param array $form_state
   *
   * @return array
   *   An renderable FAPI array.
   */
  public function getNodeForm(array &$form_state = NULL) {
    global $user;
    $form = array();

    // Mark this form to be processed by quiz_form_alter. quiz_form_alter will
    // among other things hide the revision fieldset if the user don't have
    // permission to control the revisioning manually.
    $form['#quiz_check_revision_access'] = TRUE;

    // Allow user to set title?
    if (user_access('edit question titles')) {
      $form['helper']['#theme'] = 'quiz_question_creation_form';
      $form['title'] = array(
        '#type' => 'textfield',
        '#title' => t('Title'),
        '#maxlength' => 255,
        '#default_value' => $this->node->title,
        '#required' => TRUE,
        '#description' => t('Add a title that will help distinguish this question from other questions. This will not be seen during the @quiz.', array(
          '@quiz' => QUIZ_NAME,
        )),
      );
    }
    else {
      $form['title'] = array(
        '#type' => 'value',
        '#value' => $this->node->title,
      );
    }

    // Store quiz id in the form.
    $form['quiz_nid'] = array(
      '#type' => 'hidden',
    );
    $form['quiz_vid'] = array(
      '#type' => 'hidden',
    );
    if (isset($_GET['quiz_nid']) && isset($_GET['quiz_vid'])) {
      $form['quiz_nid']['#value'] = intval($_GET['quiz_nid']);
      $form['quiz_vid']['#value'] = intval($_GET['quiz_vid']);
    }

    // Identify this node as a quiz question type so that it can be recognized
    // by other modules effectively.
    $form['is_quiz_question'] = array(
      '#type' => 'value',
      '#value' => TRUE,
    );
    if (!empty($this->node->nid)) {
      if ($properties = entity_load('quiz_question', FALSE, array(
        'nid' => $this->node->nid,
        'vid' => $this->node->vid,
      ))) {
        $quiz_question = reset($properties);
      }
    }
    $form['feedback'] = array(
      '#type' => 'text_format',
      '#title' => t('Question feedback'),
      '#default_value' => !empty($quiz_question->feedback) ? $quiz_question->feedback : '',
      '#format' => !empty($quiz_question->feedback_format) ? $quiz_question->feedback_format : filter_default_format(),
      '#description' => t('This feedback will show when configured and the user answers a question, regardless of correctness.'),
    );

    // Add question type specific content.
    $form = array_merge($form, $this
      ->getCreationForm($form_state));
    if (variable_get('quiz_auto_revisioning', 1) && $this
      ->hasBeenAnswered()) {
      $log = t('The current revision has been answered. We create a new revision so that the reports from the existing answers stays correct.');
      $this->node->revision = 1;
      $this->node->log = $log;
    }
    return $form;
  }

  /**
   * Retrieve information relevant for viewing the node.
   *
   * (This data is generally added to the node's extra field.)
   *
   * @return array
   *   Content array.
   */
  public function getNodeView() {
    $content = array();
    return $content;
  }

  /**
   * Getter function returning properties to be loaded when the node is loaded.
   *
   * @see load hook in quiz_question.module (quiz_question_load)
   *
   * @return array
   *   Array with all additional node properties.
   */
  public function getNodeProperties() {
    if (isset($this->nodeProperties)) {
      return $this->nodeProperties;
    }
    $props = array();
    $result = db_query('SELECT *
      FROM {quiz_question_properties}
      WHERE nid = :nid AND vid = :vid', array(
      ':nid' => $this->node->nid,
      ':vid' => $this->node->vid,
    ));
    $row = $result
      ->fetch();
    if ($row) {
      $props['max_score'] = $row->max_score;
      $props['feedback']['value'] = $row->feedback;
      $props['feedback']['format'] = $row->feedback_format;
    }
    $props['is_quiz_question'] = TRUE;
    $this->nodeProperties = $props;
    return $props;
  }

  /**
   * Responsible for handling insert/update of question-specific data.
   *
   * This is typically called from within the Node API, so there is no need
   * to save the node.
   *
   * The $is_new flag is set to TRUE whenever the node is being initially
   * created.
   *
   * A save function is required to handle the following three situations:
   * - A new node is created ($is_new is TRUE).
   * - A new node *revision* is created ($is_new is NOT set, because the
   *   node itself is not new).
   * - An existing node revision is modified.
   *
   * @see hook_update and hook_insert in quiz_question.module
   *
   * @param bool $is_new
   *   TRUE when the node is initially created.
   */
  public function save($is_new = FALSE) {

    // We call the abstract function saveNodeProperties to save type specific
    // data.
    $this
      ->saveNodeProperties($this->node->is_new);
    db_merge('quiz_question_properties')
      ->key(array(
      'nid' => $this->node->nid,
      'vid' => $this->node->vid,
    ))
      ->fields(array(
      'nid' => $this->node->nid,
      'vid' => $this->node->vid,
      'max_score' => $this
        ->getMaximumScore(),
      'feedback' => !empty($this->node->feedback['value']) ? $this->node->feedback['value'] : '',
      'feedback_format' => !empty($this->node->feedback['format']) ? $this->node->feedback['format'] : filter_default_format(),
    ))
      ->execute();

    // Save what quizzes this question belongs to.
    // @kludge the quiz nid/vid are still on the node
    if (!empty($this->node->quiz_nid)) {
      $this
        ->saveRelationships($this->node->quiz_nid, $this->node->quiz_vid);
    }
    if (!empty($this->node->revision)) {

      // @kludge strange way of redirecting, since we do not have access to
      // $form(_state) here
      unset($_GET['destination']);
      unset($_REQUEST['edit']['destination']);
      $_REQUEST['edit']['destination'] = "node/{$this->node->nid}/question-revision-actions";
    }
  }

  /**
   * Delete question data from the database.
   *
   * Called by quiz_question_delete (hook_delete).
   *
   * Child classes must call super.
   *
   * @param bool $only_this_version
   *   If the $only_this_version flag is TRUE, then only the particular
   *   nid/vid combo should be deleted. Otherwise, all questions with the
   *   current nid can be deleted.
   */
  public function delete($only_this_version = FALSE) {

    // Delete properties.
    $delete = db_delete('quiz_question_properties')
      ->condition('nid', $this->node->nid);
    if ($only_this_version) {
      $delete
        ->condition('vid', $this->node->vid);
    }
    $delete
      ->execute();
  }

  /**
   * Provides validation for question before it is created.
   *
   * When a new question is created and initially submitted, this is
   * called to validate that the settings are acceptable.
   *
   * @param array $form
   *   The processed form.
   */
  public abstract function validateNode(array &$form);

  /**
   * Get the form through which the user will answer the question.
   *
   * @param array $form_state
   *   The FAPI form_state array.
   * @param int $result_id
   *   The result id.
   * @return array
   *   An renderable FAPI array.
   */
  public function getAnsweringForm(array $form_state = NULL, $result_id) {
    $form = array();
    $form['#element_validate'] = array(
      'quiz_question_element_validate',
    );
    return $form;
  }

  /**
   * Get the form used to create a new question.
   *
   * @param array $form_state
   *   The FAPI form_state array.
   * @return array
   *   An renderable FAPI array.
   */
  public abstract function getCreationForm(array &$form_state = NULL);

  /**
   * Get the maximum possible score for this question.
   *
   * @return int
   */
  public abstract function getMaximumScore();

  /**
   * Save question type specific node properties.
   */
  public abstract function saveNodeProperties();

  /**
   * Save this Question to the specified Quiz.
   *
   * @param $nid
   *   The node ID.
   * @param $vid
   *   The revision ID.
   */
  public function saveRelationships($nid, $vid) {
    $quiz_node = node_load($nid, $vid);
    if (variable_get('quiz_auto_revisioning', 1) && quiz_has_been_answered($quiz_node)) {

      // We need to revise the quiz node if it has been answered.
      $quiz_node->revision = 1;
      $quiz_node->log = t('The current revision has been answered. We create a new revision so that the reports from the existing answers stays correct.');
      node_save($quiz_node);
      drupal_set_message(t('New revision has been created for the @quiz %n', array(
        '%n' => $quiz_node->title,
        '@quiz' => QUIZ_NAME,
      )));
    }
    $insert_values = array();
    $insert_values['parent_nid'] = $quiz_node->nid;
    $insert_values['parent_vid'] = $quiz_node->vid;
    $insert_values['child_nid'] = $this->node->nid;
    $insert_values['child_vid'] = $this->node->vid;
    $insert_values['max_score'] = $this
      ->getMaximumScore();
    $insert_values['auto_update_max_score'] = $this
      ->autoUpdateMaxScore() ? 1 : 0;
    $insert_values['weight'] = 1 + db_query('SELECT MAX(weight) FROM {quiz_node_relationship} WHERE parent_vid = :vid', array(
      ':vid' => $quiz_node->vid,
    ))
      ->fetchField();
    $randomization = db_query('SELECT randomization FROM {quiz_node_properties} WHERE nid = :nid AND vid = :vid', array(
      ':nid' => $quiz_node->nid,
      ':vid' => $quiz_node->vid,
    ))
      ->fetchField();
    $insert_values['question_status'] = $randomization == 2 ? QUIZ_QUESTION_RANDOM : QUIZ_QUESTION_ALWAYS;
    entity_create('quiz_question_relationship', $insert_values)
      ->save();

    // Update max_score for relationships if auto update max score is enabled
    // for question.
    $quizzes_to_update = array();
    $result = db_query('SELECT parent_vid as vid from {quiz_node_relationship} where child_nid = :nid and child_vid = :vid and auto_update_max_score=1', array(
      ':nid' => $this->node->nid,
      ':vid' => $this->node->vid,
    ));
    foreach ($result as $record) {
      $quizzes_to_update[] = $record->vid;
    }
    db_update('quiz_node_relationship')
      ->fields(array(
      'max_score' => $this
        ->getMaximumScore(),
    ))
      ->condition('child_nid', $this->node->nid)
      ->condition('child_vid', $this->node->vid)
      ->condition('auto_update_max_score', 1)
      ->execute();
    quiz_update_max_score_properties($quizzes_to_update);
    quiz_update_max_score_properties(array(
      $quiz_node->vid,
    ));
  }

  /**
   * Finds out if a question has been answered or not.
   *
   * This function also returns TRUE if a quiz that this question belongs to
   * have been answered. Even if the question itself haven't been answered.
   * This is because the question might have been rendered and a user is about
   * to answer it...
   *
   * @return bool
   *   TRUE if question has been answered or is about to be answered...
   */
  public function hasBeenAnswered() {
    if (!isset($this->node->vid)) {
      return FALSE;
    }
    $answered = db_query_range('SELECT 1 FROM {quiz_node_results} qnres
            JOIN {quiz_node_relationship} qnrel ON (qnres.vid = qnrel.parent_vid)
            WHERE qnrel.child_vid = :child_vid', 0, 1, array(
      ':child_vid' => $this->node->vid,
    ))
      ->fetch();
    return $answered ? TRUE : FALSE;
  }

  /**
   * Determines if the user can view the correct answers.
   *
   * @return true|null
   *   TRUE if the view may include the correct answers to the question.
   */
  public function viewCanRevealCorrect() {
    global $user;
    $reveal_correct[] = user_access('view any quiz question correct response');
    $reveal_correct[] = $user->uid == $this->node->uid;
    if (array_filter($reveal_correct)) {
      return TRUE;
    }
  }

  /**
   * Utility function that returns the format of the node body.
   *
   * @return string|null
   *   The format of the node body
   */
  protected function getFormat() {
    $node = isset($this->node) ? $this->node : $this->question;
    $body = field_get_items('node', $node, 'body');
    return isset($body[0]['format']) ? $body[0]['format'] : NULL;
  }

  /**
   * This may be overridden in subclasses. If it returns true,
   * it means the max_score is updated for all occurrences of
   * this question in quizzes.
   *
   * @return bool
   */
  protected function autoUpdateMaxScore() {
    return FALSE;
  }

  /**
   * Validate a user's answer.
   *
   * @param array $element
   *   The form element of this question.
   * @param mixed $value
   *   The value submitted by the user. Depending on the question type's form,
   *   the data type will vary.
   */
  public function getAnsweringFormValidate(array &$element, &$value) {
  }

  /**
   * Is this question graded?
   *
   * Questions like Quiz Directions, Quiz Page, and Scale are not.
   *
   * By default, questions are expected to be gradeable
   *
   * @return bool
   */
  public function isGraded() {
    return TRUE;
  }

  /**
   * Does this question type give feedback?
   *
   * Questions like Quiz Directions and Quiz Pages do not.
   *
   * By default, questions give feedback
   *
   * @return bool
   */
  public function hasFeedback() {
    return TRUE;
  }

  /**
   * Is this "question" an actual question?
   *
   * For example, a Quiz Page is not a question, neither is a "quiz directions".
   *
   * Returning FALSE here means that the question will not be numbered, and
   * possibly other things.
   *
   * @return bool
   */
  public function isQuestion() {
    return TRUE;
  }

}

Members

Name	Modifiers	Type	Description	Overrides
QuizQuestion::$node	public	property	The current node for this question.
QuizQuestion::$nodeProperties	public	property
QuizQuestion::autoUpdateMaxScore	protected	function	This may be overridden in subclasses. If it returns true, it means the max_score is updated for all occurrences of this question in quizzes.
QuizQuestion::delete	public	function	Delete question data from the database.	6
QuizQuestion::getAnsweringForm	public	function	Get the form through which the user will answer the question.	8
QuizQuestion::getAnsweringFormValidate	public	function	Validate a user's answer.	6
QuizQuestion::getBodyFieldTitle	public	function	Allow question types to override the body field title.	4
QuizQuestion::getCreationForm	abstract public	function	Get the form used to create a new question.	9
QuizQuestion::getFormat	protected	function	Utility function that returns the format of the node body.
QuizQuestion::getMaximumScore	abstract public	function	Get the maximum possible score for this question.	9
QuizQuestion::getNodeForm	public	function	Returns a node form to quiz_question_form.
QuizQuestion::getNodeProperties	public	function	Getter function returning properties to be loaded when the node is loaded.	6
QuizQuestion::getNodeView	public	function	Retrieve information relevant for viewing the node.	6
QuizQuestion::hasBeenAnswered	public	function	Finds out if a question has been answered or not.
QuizQuestion::hasFeedback	public	function	Does this question type give feedback?	3
QuizQuestion::isGraded	public	function	Is this question graded?	2
QuizQuestion::isQuestion	public	function	Is this "question" an actual question?	2
QuizQuestion::save	public	function	Responsible for handling insert/update of question-specific data.
QuizQuestion::saveNodeProperties	abstract public	function	Save question type specific node properties.	9
QuizQuestion::saveRelationships	public	function	Save this Question to the specified Quiz.
QuizQuestion::validateNode	abstract public	function	Provides validation for question before it is created.	9
QuizQuestion::viewCanRevealCorrect	public	function	Determines if the user can view the correct answers.
QuizQuestion::__construct	public	function	QuizQuestion constructor stores the node object.	1