How to get data in the service onPostSerialize?

[iBet7o]

Hello,

I try to add more fields to the response, but do not know how you get the data I need.

This is my code.

. . .
public function onPostSerialize(ObjectEvent $event)
{
    if ($event->getObject() instanceof Historia)
    {
        $visitor = $event->getVisitor();

        $img1 = $this->avalancheService->getBrowserPath($this->dirImages . $visitor->getData('image'), 'frontend_full_width');
        $img2 = $this->avalancheService->getBrowserPath($this->dirImages . $visitor->getData('image'), 'frontend_medium_width');

        $visitor->addData('img_full_width', $img1);
        $visitor->addData('img_medium_width', $img2);
    }
}
. . .

Thanks in advance