Issue #22 - Split maintenance.php into preview.php and file.php

preview.php

@@ -0,0 +1,41 @@
+<?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/>.
+
+/**
+ * This page is used to regenerate and preview a maintenance mode static page.
+ *
+ * @package    auth_outage
+ * @author     Daniel Thee Roperto <daniel.roperto@catalyst-au.net>
+ * @copyright  2016 Catalyst IT
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ *
+ * @var stdClass $CFG
+ */
+
+use auth_outage\dml\outagedb;
+use auth_outage\local\controllers\maintenance_static_page;
+
+require_once(__DIR__.'/../../config.php');
+$id = optional_param('id', null, PARAM_INT);
+$outage = is_null($id) ? outagedb::get_next_starting() : outagedb::get_by_id($id);
+if (is_null($outage)) {
+    throw new invalid_parameter_exception('Outage not found.');
+}
+
+$page = maintenance_static_page::create_from_outage($outage);
+$page->set_preview(true);
+$page->generate();
+readfile($page->get_template_file());