gistfile1.txt

    public function interact(Tag $tag, TagData $input)
    {   
        if ($input->role) 
        {   
            $role = $input->role; 
            $input->role = json_encode($role); 
        }   

        // We only want to work with values that have been changed
            
        $update = $input->getDifferent($tag->asArray());
        if (!$this->valid->check($update))
            throw new ValidatorException("Failed to validate tag", $this->valid->errors());

        // Determine what changes to make in the tag
        $this->updated = $update->asArray();

        $this->repo->updateTag($tag->id, $this->updated);

        // Reflect the changes in the tag
        $tag->setData($this->updated);

        return $tag;
    }