Laravel 5.1, Dingo - Nested Transformers

Is there an elegant way to embed transformers to use relationships? I'm looking to create a REST interface that allows collections to conditionally include relationship models. I've been a bit successful so far, but it seems to have crashed a bit when it comes to transformers (I admit I'm a bit new to Laravel 5.1 and Dingo). I want this to be as dry as possible, so that if the relationship or attributes change in the future, it's pretty easy to change.

For example, a simple scenario where a user can receive one or more messages (the user has many messages received), I can do the following in the UserTransformer:

<?php

namespace App\Transformers;

use App\Models\User;
use League\Fractal;

class UserTransformer extends Fractal\TransformerAbstract
{
    public function transform(User $user)
    {
        // Transform the basic model
        $returnUser = [
            'id'           => (int) $user->id,
            'email'        => $user->email,
            'role'         => $user->role,
            'status'       => $user->status,
            'links'        => [
                [
                    'rel' => 'self',
                    'uri' => '/users/'.$user->id
                ]
            ]
        ];

        // Transform relationships, but only if they exist and are requested
        if (isset($user->receivedMessages))
        {
            $returnUser['received_messages'] = [];

            foreach ($user->receivedMessages as $msg)
            {
                $returnUser['received_messages'][] = [
                    'id'      => $msg->id,
                    'read'    => $msg->read,
                    'content' => $msg->content
                ];
            }
        }
        return $returnUser;
    }
}

      

        
        
        
      

    

In this case, I would like to nest / apply the MesagesTransformer to the corresponding received messages to format the output so that all REST output remains consistent in every way. Is it possible? Thank!