public function search_courses($searchcriteria) {
        global $CFG;
        $content = '';
        if (!empty($searchcriteria)) {
            // print search results

            $displayoptions = array('sort' => array('displayname' => 1));
            // take the current page and number of results per page from query
            $perpage = optional_param('perpage', 0, PARAM_RAW);
            if ($perpage !== 'all') {
                $displayoptions['limit'] = ((int)$perpage <= 0) ? $CFG->coursesperpage : (int)$perpage;
                $page = optional_param('page', 0, PARAM_INT);
                $displayoptions['offset'] = $displayoptions['limit'] * $page;
            }
            // options 'paginationurl' and 'paginationallowall' are only used in method coursecat_courses()
            $displayoptions['paginationurl'] = new moodle_url('/course/search.php', $searchcriteria);
            $displayoptions['paginationallowall'] = true; // allow adding link 'View all'

            $class = 'course-search-result';
            foreach ($searchcriteria as $key => $value) {
                if (!empty($value)) {
                    $class .= ' course-search-result-'. $key;
                }
            }
            $chelper = new coursecat_helper();
            $chelper->set_show_courses(self::COURSECAT_SHOW_COURSES_EXPANDED_WITH_CAT)->
                    set_courses_display_options($displayoptions)->
                    set_search_criteria($searchcriteria)->
                    set_attributes(array('class' => $class));

            $courses = core_course_category::search_courses($searchcriteria, $chelper->get_courses_display_options());
            $totalcount = core_course_category::search_courses_count($searchcriteria);
            $courseslist = $this->coursecat_courses($chelper, $courses, $totalcount);

            if (!$totalcount) {
                if (!empty($searchcriteria['search'])) {
                    $content .= $this->heading(get_string('nocoursesfound', '', $searchcriteria['search']));
                } else {
                    $content .= $this->heading(get_string('novalidcourses'));
                }
            } else {
                $content .= $this->heading(get_string('searchresults'). ": $totalcount");
                $content .= $courseslist;
            }

            if (!empty($searchcriteria['search'])) {
                // print search form only if there was a search by search string, otherwise it is confusing
                $content .= $this->box_start('generalbox mdl-align');
                $content .= $this->course_search_form($searchcriteria['search']);
                $content .= $this->box_end();
            }
        } else {
            // just print search form
            $content .= $this->box_start('generalbox mdl-align');
            $content .= $this->course_search_form();
            $content .= $this->box_end();
        }
        return $content;
    }