silverstripe / silverstripe-versioned-admin

src/Controllers/CMSPageHistoryViewerController.php

<?php

namespace SilverStripe\VersionedAdmin\Controllers;

use SilverStripe\CMS\Controllers\CMSMain;
use SilverStripe\Forms\FieldList;
use SilverStripe\Forms\Form;
use SilverStripe\Forms\HiddenField;
use SilverStripe\ORM\DataObject;
use SilverStripe\VersionedAdmin\Forms\HistoryViewerField;

if (!class_exists(CMSMain::class)) {
    return;
}

/**
 * The history viewer controller replaces the {@link CMSPageHistoryController} and uses the React based
 * {@link HistoryViewerField} to display the history for a {@link DataObject} that has the {@link Versioned}
 * extension.
 */
class CMSPageHistoryViewerController extends CMSMain
{
    private static $url_segment = 'pages/history';

The private property $url_segment is not used, and could be removed.

    private static $url_rule = '/$Action/$ID/$VersionID/$OtherVersionID';

The private property $url_rule is not used, and could be removed.

    /**
     * {@inheritDoc}
     *
     * This is one higher than CMSPageHistoryController to give it priority
     */
    private static $url_priority = 43;

The private property $url_priority is not used, and could be removed.

    private static $required_permission_codes = 'CMS_ACCESS_CMSMain';

The private property $required_permission_codes is not used, and could be removed.

    public function getEditForm($id = null, $fields = null)
    {
        /** @var DataObject $record */
        $record = $this->getRecord($id ?: $this->currentPageID());

        /** @var Form $form */
        $form = parent::getEditForm($id);
        $form->addExtraClass('history-viewer__form');
        // Disable default CMS preview
        $form->removeExtraClass('cms-previewable');

        if ($record) {

$record is of type SilverStripe\CMS\Model\SiteTree, thus it always evaluated to true.

            $fieldList = FieldList::create(
                HiddenField::create('ID', null, $record->ID),
                HistoryViewerField::create('PageHistory')
                    ->addExtraClass('history-viewer--standalone')
                    ->setForm($form)
            );
            $form->setFields($fieldList);
        }

        return $form;
    }

    public function getTabIdentifier()
    {
        return 'history';
    }
}