lib/components/web/widgets/form/FileStorage.php
public function prepareItem($engine)
    {
        $item = clone $this->item;
        $item->inputOptions['data-engine'] = $engine->primaryKey;
        Html::addCssClass($item->inputOptions, 'storage-field');

        return $item;
    }
public function prepareItem($engine)
    {
        $item = clone $this->item;
        $item->inputOptions['data-engine'] = $engine->primaryKey;
        Html::addCssClass($item->inputOptions, 'storage-field');

        return $item;
    }
[[@doctodo method_description:prepareItem]].

@param [[@doctodo param_type:engine]] $engine [[@doctodo param_description:engine]]

@return [[@doctodo return_type:prepareItem]] [[@doctodo return_description:prepareItem]]