function set_versionid($versionid)
 {
     $this->version = wiki_get_version($versionid);
 }

    /**
     * Prints lists of versions which can be deleted
     *
     * @global core_renderer $OUTPUT
     * @global moodle_page $PAGE
     */
    private function print_delete_version() {
        global $OUTPUT, $PAGE;
        $pageid = $this->page->id;

        // versioncount is the latest version
        $versioncount = wiki_count_wiki_page_versions($pageid) - 1;
        $versions = wiki_get_wiki_page_versions($pageid, 0, $versioncount);

        // We don't want version 0 to be displayed
        // version 0 is blank page
        if (end($versions)->version == 0) {
            array_pop($versions);
        }

        $contents = array();
        $version0page = wiki_get_wiki_page_version($this->page->id, 0);
        $creator = wiki_get_user_info($version0page->userid);
        $a = new stdClass();
        $a->date = userdate($this->page->timecreated, get_string('strftimedaydatetime', 'langconfig'));
        $a->username = fullname($creator);
        echo $OUTPUT->heading(get_string('createddate', 'wiki', $a), 4, 'wiki_headingtime');
        if ($versioncount > 0) {
            /// If there is only one version, we don't need radios nor forms
            if (count($versions) == 1) {
                $row = array_shift($versions);
                $username = wiki_get_user_info($row->userid);
                $picture = $OUTPUT->user_picture($username);
                $date = userdate($row->timecreated, get_string('strftimedate', 'langconfig'));
                $time = userdate($row->timecreated, get_string('strftimetime', 'langconfig'));
                $versionid = wiki_get_version($row->id);
                $versionlink = new moodle_url('/mod/wiki/viewversion.php', array('pageid' => $pageid, 'versionid' => $versionid->id));
                $userlink = new moodle_url('/user/view.php', array('id' => $username->id, 'course' => $PAGE->cm->course));
                $picturelink = $picture . html_writer::link($userlink->out(false), fullname($username));
                $historydate = $OUTPUT->container($date, 'wiki_histdate');
                $contents[] = array('', html_writer::link($versionlink->out(false), $row->version), $picturelink, $time, $historydate);

                //Show current version
                $table = new html_table();
                $table->head = array('', get_string('version'), get_string('user'), get_string('modified'), '');
                $table->data = $contents;
                $table->attributes['class'] = 'mdl-align';

                echo html_writer::table($table);
            } else {
                $lastdate = '';
                $rowclass = array();

                foreach ($versions as $version) {
                    $user = wiki_get_user_info($version->userid);
                    $picture = $OUTPUT->user_picture($user, array('popup' => true));
                    $date = userdate($version->timecreated, get_string('strftimedate'));
                    if ($date == $lastdate) {
                        $date = '';
                        $rowclass[] = '';
                    } else {
                        $lastdate = $date;
                        $rowclass[] = 'wiki_histnewdate';
                    }

                    $time = userdate($version->timecreated, get_string('strftimetime', 'langconfig'));
                    $versionid = wiki_get_version($version->id);
                    if ($versionid) {
                        $url = new moodle_url('/mod/wiki/viewversion.php', array('pageid' => $pageid, 'versionid' => $versionid->id));
                        $viewlink = html_writer::link($url->out(false), $version->version);
                    } else {
                        $viewlink = $version->version;
                    }

                    $userlink = new moodle_url('/user/view.php', array('id' => $version->userid, 'course' => $PAGE->cm->course));
                    $picturelink = $picture . html_writer::link($userlink->out(false), fullname($user));
                    $historydate = $OUTPUT->container($date, 'wiki_histdate');
                    $radiofromelement = $this->choose_from_radio(array($version->version  => null), 'fromversion', 'M.mod_wiki.deleteversion()', $versioncount, true);
                    $radiotoelement = $this->choose_from_radio(array($version->version  => null), 'toversion', 'M.mod_wiki.deleteversion()', $versioncount, true);
                    $contents[] = array( $radiofromelement . $radiotoelement, $viewlink, $picturelink, $time, $historydate);
                }

                $table = new html_table();
                $table->head = array(get_string('deleteversions', 'wiki'), get_string('version'), get_string('user'), get_string('modified'), '');
                $table->data = $contents;
                $table->attributes['class'] = 'generaltable mdl-align';
                $table->rowclasses = $rowclass;

                ///Print the form
                echo html_writer::start_tag('form', array('action'=>new moodle_url('/mod/wiki/admin.php'), 'method' => 'post'));
                echo html_writer::tag('div', html_writer::empty_tag('input', array('type' => 'hidden', 'name' => 'pageid', 'value' => $pageid)));
                echo html_writer::empty_tag('input', array('type' => 'hidden', 'name' => 'option', 'value' => $this->view));
                echo html_writer::empty_tag('input', array('type' => 'hidden', 'name' => 'sesskey', 'value' =>  sesskey()));
                echo html_writer::table($table);
                echo html_writer::start_tag('div', array('class' => 'mdl-align'));
                echo html_writer::empty_tag('input', array('type' => 'submit', 'class' => 'wiki_form-button', 'value' => get_string('deleteversions', 'wiki')));
                echo html_writer::end_tag('div');
                echo html_writer::end_tag('form');
            }
        } else {
//.........这里部分代码省略.........

 /**
  * Test page_version_restored event.
  */
 public function test_page_version_restored()
 {
     $this->setUp();
     $page = $this->wikigenerator->create_first_page($this->wiki);
     $context = context_module::instance($this->wiki->cmid);
     $version = wiki_get_version(1);
     // Triggering and capturing the event.
     $sink = $this->redirectEvents();
     wiki_restore_page($page, $version, $context);
     $events = $sink->get_events();
     $this->assertCount(2, $events);
     $event = array_pop($events);
     // Checking that the event contains the expected values.
     $this->assertInstanceOf('\\mod_wiki\\event\\page_version_restored', $event);
     $this->assertEquals($context, $event->get_context());
     $this->assertEquals($version->id, $event->objectid);
     $this->assertEquals($page->id, $event->other['pageid']);
     $expected = array($this->course->id, 'wiki', 'restore', 'view.php?pageid=' . $page->id, $page->id, $this->wiki->id);
     $this->assertEventLegacyLogData($expected, $event);
 }