/**
* Delete a course
* This function deletes a whole course-area from the platform. When the
* given course is a virtual course, the database and directory will not be
* deleted.
* When the given course is a real course, also all virtual courses refering
* to the given course will be deleted.
* Considering the fact that we remove all traces of the course in the main
* database, it makes sense to remove all tracking as well (if stats databases exist)
* so that a new course created with this code would not use the remains of an older
* course.
*
* @param string The code of the course to delete
* @todo When deleting a virtual course: unsubscribe users from that virtual
* course from the groups in the real course if they are not subscribed in
* that real course.
* @todo Remove globals
*/
public static function delete_course($code)
{
$table_course = Database::get_main_table(TABLE_MAIN_COURSE);
$table_course_user = Database::get_main_table(TABLE_MAIN_COURSE_USER);
$table_session_course = Database::get_main_table(TABLE_MAIN_SESSION_COURSE);
$table_session_course_user = Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER);
$table_course_survey = Database::get_main_table(TABLE_MAIN_SHARED_SURVEY);
$table_course_survey_question = Database::get_main_table(TABLE_MAIN_SHARED_SURVEY_QUESTION);
$table_course_survey_question_option = Database::get_main_table(TABLE_MAIN_SHARED_SURVEY_QUESTION_OPTION);
$table_course_rel_url = Database::get_main_table(TABLE_MAIN_ACCESS_URL_REL_COURSE);
$table_stats_hotpots = Database::get_main_table(TABLE_STATISTIC_TRACK_E_HOTPOTATOES);
$table_stats_attempt = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);
$table_stats_exercises = Database::get_main_table(TABLE_STATISTIC_TRACK_E_EXERCISES);
$table_stats_access = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ACCESS);
$table_stats_lastaccess = Database::get_main_table(TABLE_STATISTIC_TRACK_E_LASTACCESS);
$table_stats_course_access = Database::get_main_table(TABLE_STATISTIC_TRACK_E_COURSE_ACCESS);
$table_stats_online = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ONLINE);
$table_stats_default = Database::get_main_table(TABLE_STATISTIC_TRACK_E_DEFAULT);
$table_stats_downloads = Database::get_main_table(TABLE_STATISTIC_TRACK_E_DOWNLOADS);
$table_stats_links = Database::get_main_table(TABLE_STATISTIC_TRACK_E_LINKS);
$table_stats_uploads = Database::get_main_table(TABLE_STATISTIC_TRACK_E_UPLOADS);
$codeFiltered = Database::escape_string($code);
$sql = "SELECT * FROM {$table_course} WHERE code='" . $codeFiltered . "'";
$res = Database::query($sql);
if (Database::num_rows($res) == 0) {
return;
}
$sql = "SELECT * FROM {$table_course}\n WHERE code = '" . $codeFiltered . "'";
$res = Database::query($sql);
$course = Database::fetch_array($res);
$courseId = $course['id'];
$count = 0;
if (api_is_multiple_url_enabled()) {
$url_id = 1;
if (api_get_current_access_url_id() != -1) {
$url_id = api_get_current_access_url_id();
}
UrlManager::delete_url_rel_course($courseId, $url_id);
$count = UrlManager::getCountUrlRelCourse($courseId);
}
if ($count == 0) {
self::create_database_dump($code);
$course_tables = AddCourse::get_course_tables();
// Cleaning c_x tables
if (!empty($courseId)) {
foreach ($course_tables as $table) {
$table = Database::get_course_table($table);
$sql = "DELETE FROM {$table} WHERE c_id = {$courseId} ";
Database::query($sql);
}
}
$course_dir = api_get_path(SYS_COURSE_PATH) . $course['directory'];
$archive_dir = api_get_path(SYS_ARCHIVE_PATH) . $course['directory'] . '_' . time();
if (is_dir($course_dir)) {
rename($course_dir, $archive_dir);
}
// Unsubscribe all users from the course
$sql = "DELETE FROM {$table_course_user} WHERE c_id='" . $courseId . "'";
Database::query($sql);
// Delete the course from the sessions tables
$sql = "DELETE FROM {$table_session_course} WHERE c_id='" . $courseId . "'";
Database::query($sql);
$sql = "DELETE FROM {$table_session_course_user} WHERE c_id='" . $courseId . "'";
Database::query($sql);
// Delete from Course - URL
$sql = "DELETE FROM {$table_course_rel_url} WHERE c_id = '" . $courseId . "'";
Database::query($sql);
$sql = 'SELECT survey_id FROM ' . $table_course_survey . ' WHERE course_code="' . $codeFiltered . '"';
$result_surveys = Database::query($sql);
while ($surveys = Database::fetch_array($result_surveys)) {
$survey_id = $surveys[0];
$sql = 'DELETE FROM ' . $table_course_survey_question . ' WHERE survey_id="' . $survey_id . '"';
Database::query($sql);
$sql = 'DELETE FROM ' . $table_course_survey_question_option . ' WHERE survey_id="' . $survey_id . '"';
Database::query($sql);
$sql = 'DELETE FROM ' . $table_course_survey . ' WHERE survey_id="' . $survey_id . '"';
Database::query($sql);
}
// Cleaning group categories
$groupCategories = GroupManager::get_categories($course['code']);
if (!empty($groupCategories)) {
foreach ($groupCategories as $category) {
GroupManager::delete_category($category['id'], $course['code']);
}
}
// Cleaning groups
$groups = GroupManager::get_groups();
if (!empty($groups)) {
$groupList = array_column($groups, 'id');
GroupManager::delete_groups($groupList);
}
// Delete the course from the stats tables
$sql = "DELETE FROM {$table_stats_hotpots} WHERE c_id = {$courseId}";
Database::query($sql);
$sql = "DELETE FROM {$table_stats_attempt} WHERE c_id = {$courseId}";
Database::query($sql);
$sql = "DELETE FROM {$table_stats_exercises} WHERE c_id = {$courseId}";
Database::query($sql);
$sql = "DELETE FROM {$table_stats_access} WHERE c_id = {$courseId}";
Database::query($sql);
$sql = "DELETE FROM {$table_stats_lastaccess} WHERE c_id = {$courseId}";
Database::query($sql);
$sql = "DELETE FROM {$table_stats_course_access} WHERE c_id = {$courseId}";
Database::query($sql);
$sql = "DELETE FROM {$table_stats_online} WHERE c_id = {$courseId}";
Database::query($sql);
// Do not delete rows from track_e_default as these include course
// creation and other important things that do not take much space
// but give information on the course history
//$sql = "DELETE FROM $table_stats_default WHERE c_id = $courseId";
//Database::query($sql);
$sql = "DELETE FROM {$table_stats_downloads} WHERE c_id = {$courseId}";
Database::query($sql);
$sql = "DELETE FROM {$table_stats_links} WHERE c_id = {$courseId}";
Database::query($sql);
$sql = "DELETE FROM {$table_stats_uploads} WHERE c_id = {$courseId}";
Database::query($sql);
// Delete the course from the database
$sql = "DELETE FROM {$table_course} WHERE code = '" . $codeFiltered . "'";
Database::query($sql);
// delete extra course fields
$extraFieldValues = new ExtraFieldValue('course');
$extraFieldValues->deleteValuesByItem($courseId);
// Add event to system log
$user_id = api_get_user_id();
Event::addEvent(LOG_COURSE_DELETE, LOG_COURSE_CODE, $code, api_get_utc_datetime(), $user_id, $courseId);
}
}
