settings.php

<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**
 * Plugin settings page.
 * @package    block_quickmail
 * @copyright  2008-2017 Louisiana State University
 * @copyright  2008-2017 Adam Zapletal, Chad Mazilly, Philip Cali, Robert Russo
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

defined('MOODLE_INTERNAL') || die;

if ($ADMIN->fulltree) {
    require_once($CFG->dirroot . '/blocks/quickmail/lib.php');

    $select = [-1 => get_string('never'), 0 => get_string('no'), 1 => get_string('yes')];

    $allow = quickmail::_s('allowstudents');
    $allowdesc = quickmail::_s('allowstudentsdesc');
    $settings->add(
        new admin_setting_configselect(
            'block_quickmail_allowstudents',
            $allow,
            $allowdesc,
            0,
            $select
        )
    );

    $roles = $DB->get_records('role', null, 'sortorder ASC');

    $defaultsns = ['editingteacher', 'teacher', 'student'];
    $defaults = array_filter($roles, function ($role) use ($defaultsns) {
        return in_array($role->shortname, $defaultsns);
    });

    $onlynames = function ($role) {
        return $role->name ? trim(format_string($role->name)) : $role->shortname;
    };

    $selectroles = quickmail::_s('select_roles');
    $settings->add(
        new admin_setting_configmultiselect(
            'block_quickmail_roleselection',
            $selectroles,
            $selectroles,
            array_keys($defaults),
            array_map($onlynames, $roles)
        )
    );

    $settings->add(
        new admin_setting_configselect(
            'block_quickmail_receipt',
            quickmail::_s('receipt'),
            quickmail::_s('receipt_help'),
            0,
            $select
        )
    );

    $options = [
        0 => get_string('none'),
        'idnumber' => get_string('idnumber'),
        'shortname' => get_string('shortname'),
    ];

    $settings->add(
        new admin_setting_configselect(
            'block_quickmail_prepend_class',
            quickmail::_s('prepend_class'),
            quickmail::_s('prepend_class_desc'),
            0,
            $options
        )
    );

    $groupoptions = [
        'strictferpa' => get_string('strictferpa', 'block_quickmail'),
        'courseferpa' => get_string('courseferpa', 'block_quickmail'),
        'noferpa' => get_string('noferpa', 'block_quickmail'),
    ];

    $settings->add(
        new admin_setting_configselect(
            'block_quickmail_ferpa',
            quickmail::_s('ferpa'),
            quickmail::_s('ferpa_desc'),
            'strictferpa',
            $groupoptions
        )
    );

    $settings->add(
        new admin_setting_configcheckbox(
            'block_quickmail_downloads',
            quickmail::_s('downloads'),
            quickmail::_s('downloads_desc'),
            1
        )
    );

    $settings->add(
        new admin_setting_configcheckbox(
            'block_quickmail_addionalemail',
            quickmail::_s('addionalemail'),
            quickmail::_s('addionalemail_desc'),
            0
        )
    );
}