moodle add teams link

renderers.php

require_once($CFG->dirroot.'/mod/scheduler/renderer.php');
class theme_adaptable_mod_scheduler_renderer extends  mod_scheduler_renderer {
    public function render_scheduler_student_list(scheduler_student_list $studentlist) {

        $o = '';
        $toggleid = html_writer::random_id('toggle');
        if ($studentlist->expandable && count($studentlist->students) > 0) {
            $this->page->requires->yui_module('moodle-mod_scheduler-studentlist',
                            'M.mod_scheduler.studentlist.init',
                            array($toggleid, (boolean) $studentlist->expanded) );
            $imgclass = 'studentlist-togglebutton';
            $alttext = get_string('showparticipants', 'scheduler');
            $o .= $this->output->pix_icon('t/switch', $alttext, 'moodle',
                            array('id' => $toggleid, 'class' => $imgclass));
        }
        $divprops = array('id' => 'list'.$toggleid);
        $o .= html_writer::start_div('studentlist', $divprops);
        if (count($studentlist->students) > 0) {





            // CUSTOM @SAMBER (2019-11-25)
            $teamsURL = "https://teams.microsoft.com/l/chat/0/0?users=";
            foreach ($studentlist->students as $student) {
                $teamsURL .= $student->user->username . ',';
                var_dump($student->user->username);
            }
     	    $o .= html_writer::link($teamsURL, "Open in Teams", array('target' => '_blank'));
            $o .= '<br><br>';





            $editable = $studentlist->actionurl && $studentlist->editable;
            if ($editable) {
                $o .= html_writer::start_tag('form', array('action' => $studentlist->actionurl,
                                'method' => 'post', 'class' => 'studentselectform'));
            }
            foreach ($studentlist->students as $student) {
                $class = 'otherstudent';
                $checkbox = '';
                if ($studentlist->checkboxname) {
                    if ($editable) {
                        $checkbox = html_writer::checkbox($studentlist->checkboxname, $student->entryid, $student->checked, '',
                                        array('class' => 'studentselect'));
                    } else {
                        $img = $student->checked ? 'ticked' : 'unticked';
                        $checkbox = $this->render(new pix_icon($img, '', 'scheduler', array('class' => 'statictickbox')));
                    }
                }
                if ($studentlist->linkappointment) {
                    $name = $this->appointment_link($studentlist->scheduler, $student->user, $student->entryid);
                } else {
                    $name = fullname($student->user);
                }
                $studicons = '';
                $studprovided = array();
                if ($student->notesprovided) {
                    $studprovided[] = get_string('message', 'scheduler');
                }
                if ($student->filesprovided) {
                    $studprovided[] = get_string('nfiles', 'scheduler', $student->filesprovided);
                }
                if ($studprovided) {
                    $providedstr = implode(', ', $studprovided);
                    $alttext = get_string('studentprovided', 'scheduler', $providedstr);
                    $attachicon = new pix_icon('attachment', $alttext, 'scheduler', array('class' => 'studdataicon'));
                    $studicons .= $this->render($attachicon);
                }
                if ($student->highlight) {
                    $class .= ' highlight';
                }
                $picture = $this->user_picture($student->user, array('courseid' => $studentlist->scheduler->courseid));
                $grade = '';
                if ($studentlist->showgrades && $student->grade) {
                    $grade = $this->format_grade($studentlist->scheduler, $student->grade, true);
                }
                $o .= html_writer::div($checkbox . $picture . ' ' . $name . $studicons . ' ' . $grade, $class);
            }
            if ($editable) {
                $o .= html_writer::empty_tag('input', array(
                                'type' => 'submit',
                                'class' => 'studentselectsubmit',
                                'value' => $studentlist->buttontext
                ));
                $o .= html_writer::end_tag('form');
            }
        }
        $o .= html_writer::end_div();
        return $o;
    }
}