protected function checkUploadPostback()
    {
        if ($this->readOnly) {
            return;
        }

        $fileName = null;
        $quickMode = false;

        if (
            (!($uniqueId = Request::header('X-OCTOBER-FILEUPLOAD')) || $uniqueId != $this->getId()) &&
            (!$quickMode = post('X_OCTOBER_MEDIA_MANAGER_QUICK_UPLOAD'))
        ) {
            return;
        }

        try {
            if (!Input::hasFile('file_data')) {
                throw new ApplicationException('File missing from request');
            }

            $uploadedFile = Input::file('file_data');

            $fileName = $uploadedFile->getClientOriginalName();

            /*
             * Convert uppcare case file extensions to lower case
             */
            $extension = strtolower($uploadedFile->getClientOriginalExtension());
            $fileName = File::name($fileName).'.'.$extension;

            /*
             * File name contains non-latin characters, attempt to slug the value
             */
            if (!$this->validateFileName($fileName)) {
                $fileNameClean = $this->cleanFileName(File::name($fileName));
                $fileName = $fileNameClean . '.' . $extension;
            }

            /*
             * Check for unsafe file extensions
             */
            if (!$this->validateFileType($fileName)) {
                throw new ApplicationException(Lang::get('backend::lang.media.type_blocked'));
            }

            /*
             * See mime type handling in the asset manager
             */
            if (!$uploadedFile->isValid()) {
                throw new ApplicationException($uploadedFile->getErrorMessage());
            }

            $path = $quickMode ? '/uploaded-files' : Input::get('path');
            $path = MediaLibrary::validatePath($path);
            $filePath = $path.'/'.$fileName;

            /*
             * getRealPath() can be empty for some environments (IIS)
             */
            $realPath = empty(trim($uploadedFile->getRealPath()))
                             ? $uploadedFile->getPath() . DIRECTORY_SEPARATOR . $uploadedFile->getFileName()
                             : $uploadedFile->getRealPath();

            MediaLibrary::instance()->put(
                $filePath,
                File::get($realPath)
            );

            /**
             * @event media.file.upload
             * Called after a file is uploaded
             *
             * Example usage:
             *
             *     Event::listen('media.file.upload', function((\Backend\Widgets\MediaManager) $mediaWidget, (string) $path, (\Symfony\Component\HttpFoundation\File\UploadedFile) $uploadedFile) {
             *         \Log::info($path . " was upoaded.");
             *     });
             *
             * Or
             *
             *     $mediaWidget->bindEvent('file.upload', function ((string) $path, (\Symfony\Component\HttpFoundation\File\UploadedFile) $uploadedFile) {
             *         \Log::info($path . " was uploaded");
             *     });
             *
             */
            $this->fireSystemEvent('media.file.upload', [$filePath, $uploadedFile]);

            Response::json([
                'link' => MediaLibrary::url($filePath),
                'result' => 'success'
            ])->send();
        }
        catch (Exception $ex) {
            Response::json($ex->getMessage(), 400)->send();
        }

        exit;
    }