edit_form.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/>.

/**
 * Adds new instance of enrol_manual to specified course
 * or edits current instance.
 *
 * @package    enrol_manual
 * @copyright  2010 Petr Skoda  {@link http://skodak.org}
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

defined('MOODLE_INTERNAL') || die();

require_once($CFG->libdir.'/formslib.php');

class enrol_manual_edit_form extends moodleform {

    function definition() {
        $mform = $this->_form;

        list($instance, $plugin, $context) = $this->_customdata;

        $mform->addElement('header', 'header', get_string('pluginname', 'enrol_manual'));

        $options = array(ENROL_INSTANCE_ENABLED  => get_string('yes'),
                         ENROL_INSTANCE_DISABLED => get_string('no'));
        $mform->addElement('select', 'status', get_string('status', 'enrol_manual'), $options);
        $mform->addHelpButton('status', 'status', 'enrol_manual');
        $mform->setDefault('status', $plugin->get_config('status'));

        if ($instance->id) {
            $roles = get_default_enrol_roles($context, $instance->roleid);
        } else {
            $roles = get_default_enrol_roles($context, $plugin->get_config('roleid'));
        }
        $mform->addElement('select', 'roleid', get_string('defaultrole', 'role'), $roles);
        $mform->setDefault('roleid', $plugin->get_config('roleid'));

        $mform->addElement('duration', 'enrolperiod', get_string('defaultperiod', 'enrol_manual'), array('optional' => true, 'defaultunit' => 86400));
        $mform->setDefault('enrolperiod', $plugin->get_config('enrolperiod'));
        $mform->addHelpButton('enrolperiod', 'defaultperiod', 'enrol_manual');

        $options = array(0 => get_string('no'), 1 => get_string('expirynotifyenroller', 'core_enrol'), 2 => get_string('expirynotifyall', 'core_enrol'));
        $mform->addElement('select', 'expirynotify', get_string('expirynotify', 'core_enrol'), $options);
        $mform->addHelpButton('expirynotify', 'expirynotify', 'core_enrol');

        $mform->addElement('duration', 'expirythreshold', get_string('expirythreshold', 'core_enrol'), array('optional' => false, 'defaultunit' => 86400));
        $mform->addHelpButton('expirythreshold', 'expirythreshold', 'core_enrol');
        $mform->disabledIf('expirythreshold', 'expirynotify', 'eq', 0);

        $mform->addElement('hidden', 'courseid');
        $mform->setType('courseid', PARAM_INT);

        $this->add_action_buttons(true, ($instance->id ? null : get_string('addinstance', 'enrol')));

        $this->set_data($instance);
    }

    function validation($data, $files) {
        global $DB;

        $errors = parent::validation($data, $files);

        if ($data['expirynotify'] > 0 and $data['expirythreshold'] < 86400) {
            $errors['expirythreshold'] = get_string('errorthresholdlow', 'core_enrol');
        }

        return $errors;
    }
}