/**
* Tests whether a category is in use by any activity module
*
* @return boolean
* @param integer $categoryid
* @param boolean $recursive Whether to examine category children recursively
*/
function question_category_isused($categoryid, $recursive = false)
{
global $DB;
//Look at each question in the category
if ($questions = $DB->get_records('question', array('category' => $categoryid), '', 'id,qtype')) {
foreach ($questions as $question) {
if (count(question_list_instances($question->id))) {
return true;
}
}
}
//Look under child categories recursively
if ($recursive) {
if ($children = $DB->get_records('question_categories', array('parent' => $categoryid))) {
foreach ($children as $child) {
if (question_category_isused($child->id, $recursive)) {
return true;
}
}
}
}
return false;
}
/**
* Tests whether a category is in use by any activity module
*
* @return boolean
* @param integer $categoryid
* @param boolean $recursive Whether to examine category children recursively
*/
function question_category_isused($categoryid, $recursive = false)
{
//Look at each question in the category
if ($questions = get_records('question', 'category', $categoryid)) {
foreach ($questions as $question) {
if (count(question_list_instances($question->id))) {
return true;
}
}
}
//Look under child categories recursively
if ($recursive) {
if ($children = get_records('question_categories', 'parent', $categoryid)) {
foreach ($children as $child) {
if (question_category_isused($child->id, $recursive)) {
return true;
}
}
}
}
return false;
}
/**
* All non-used question categories and their questions are deleted and
* categories still used by other courses are moved to the site course.
*
* @param object $course an object representing the course
* @param boolean $feedback to specify if the process must output a summary of its work
* @return boolean
*/
function question_delete_course($course, $feedback = true)
{
global $CFG, $QTYPES;
//To detect if we have created the "container category"
$concatid = 0;
//The "container" category we'll create if we need if
$contcat = new object();
//To temporary store changes performed with parents
$parentchanged = array();
//To store feedback to be showed at the end of the process
$feedbackdata = array();
//Cache some strings
$strcatcontainer = get_string('containercategorycreated', 'quiz');
$strcatmoved = get_string('usedcategorymoved', 'quiz');
$strcatdeleted = get_string('unusedcategorydeleted', 'quiz');
if ($categories = get_records('question_categories', 'course', $course->id, 'parent', 'id, parent, name, course')) {
//Sort categories following their tree (parent-child) relationships
$categories = sort_categories_by_tree($categories);
foreach ($categories as $cat) {
//Get the full record
$category = get_record('question_categories', 'id', $cat->id);
//Check if the category is being used anywhere
if (question_category_isused($category->id, true)) {
//It's being used. Cannot delete it, so:
//Create a container category in SITEID course if it doesn't exist
if (!$concatid) {
$concat = new stdClass();
$concat->course = SITEID;
if (!isset($course->shortname)) {
$course->shortname = 'id=' . $course->id;
}
$concat->name = get_string('savedfromdeletedcourse', 'quiz', format_string($course->shortname));
$concat->info = $concat->name;
$concat->publish = 1;
$concat->stamp = make_unique_id_code();
$concatid = insert_record('question_categories', $concat);
//Fill feedback
$feedbackdata[] = array($concat->name, $strcatcontainer);
}
//Move the category to the container category in SITEID course
$category->course = SITEID;
//Assign to container if the category hasn't parent or if the parent is wrong (not belongs to the course)
if (!$category->parent || !isset($categories[$category->parent])) {
$category->parent = $concatid;
}
//If it's being used, its publish field should be 1
$category->publish = 1;
//Let's update it
update_record('question_categories', $category);
//Save this parent change for future use
$parentchanged[$category->id] = $category->parent;
//Fill feedback
$feedbackdata[] = array($category->name, $strcatmoved);
} else {
//Category isn't being used so:
//Delete it completely (questions and category itself)
//deleting questions
if ($questions = get_records("question", "category", $category->id)) {
foreach ($questions as $question) {
delete_question($question->id);
}
delete_records("question", "category", $category->id);
}
//delete the category
delete_records('question_categories', 'id', $category->id);
//Save this parent change for future use
if (!empty($category->parent)) {
$parentchanged[$category->id] = $category->parent;
} else {
$parentchanged[$category->id] = $concatid;
}
//Update all its child categories to re-parent them to grandparent.
set_field('question_categories', 'parent', $parentchanged[$category->id], 'parent', $category->id);
//Fill feedback
$feedbackdata[] = array($category->name, $strcatdeleted);
}
}
//Inform about changes performed if feedback is enabled
if ($feedback) {
$table = new stdClass();
$table->head = array(get_string('category', 'quiz'), get_string('action'));
$table->data = $feedbackdata;
print_table($table);
}
}
return true;
}
