Encore\Admin\Form\Field\File::preview PHP Method

    protected function preview()
    {
        $fileName = basename($this->value);
        return <<<EOT
<div class="file-preview-other-frame">
   <div class="file-preview-other">
   <span class="file-icon-4x"><i class="glyphicon glyphicon-file"></i></span>
</div>
   </div>
   <div class="file-preview-other-footer"><div class="file-thumbnail-footer">
    <div class="file-footer-caption" title="realm_demo.realm">{$fileName}</div>
</div></div>
EOT;
    }