adding Pagination messes up the output

A Collection and a Paginator doesn't have the same structure. Not sure if your ChatTransformer can work the same way on both. Can you dump the collection (first case) and the paginator (second case) and the content of your ChatTransformer ?

Dumps

First ouptut
object(Illuminate\Database\Eloquent\Collection)[287]
  protected 'items' => 
    array (size=1)
      0 => 
        object(App\Chat)[286]
          protected 'fillable' => 
            array (size=1)
              ...
          protected 'connection' => null
          protected 'table' => null
          protected 'primaryKey' => string 'id' (length=2)
          protected 'perPage' => int 15
          public 'incrementing' => boolean true
          public 'timestamps' => boolean true
          protected 'attributes' => 
            array (size=4)
              ...
          protected 'original' => 
            array (size=6)
              ...
          protected 'relations' => 
            array (size=1)
              ...
          protected 'hidden' => 
            array (size=0)
              ...
          protected 'visible' => 
            array (size=0)
              ...
          protected 'appends' => 
            array (size=0)
              ...
          protected 'guarded' => 
            array (size=1)
              ...
          protected 'dates' => 
            array (size=0)
              ...
          protected 'touches' => 
            array (size=0)
              ...
          protected 'observables' => 
            array (size=0)
              ...
          protected 'with' => 
            array (size=0)
              ...
          protected 'morphClass' => null
          public 'exists' => boolean true
Second ouptut
object(Illuminate\Pagination\Paginator)[289]
  protected 'hasMore' => boolean false
  protected 'items' => 
    object(Illuminate\Support\Collection)[291]
      protected 'items' => 
        array (size=1)
          0 => 
            object(App\Chat)[290]
              ...
  protected 'perPage' => string '5' (length=1)
  protected 'currentPage' => int 1
  protected 'path' => string 'http://unicorn.app:8000/api/chats/' (length=34)
  protected 'query' => 
    array (size=0)
      empty
  protected 'fragment' => null
  protected 'pageName' => string 'page' (length=4)

my ChatTransformer

<?php
namespace App\Transformers;

use App\Chat;
use Doctrine\Instantiator\Exception\InvalidArgumentException;
use Illuminate\Database\Eloquent\Model;

class ChatTransformer extends Transformer {

  public static function transform(Model $item, $args = [ ]) {
    if (!( $item instanceof Chat )) throw new InvalidArgumentException;

    $return = array();

    $return['chat_id'] = $item->id;
    $return['title'] = $item->title;

    // $firstMessage = Auth::User()->Chats()->first()->Messages()->first();

    $return['messages'] = ( new MessageTransformer() )->transformCollection( $item->messages()->take( 20 )->get() );
    $return['users'] = ( new UserTransformer() )->transformCollection( $item->users );

    return $return;
  }
}

That is extending the Trasnformer:

<?php
namespace App\Transformers;

use Illuminate\Database\Eloquent\Model;

abstract class Transformer {
  public static function transformCollection($items, $args = [ ]) {
    $var = array();
    foreach ($items as $item) {
      array_push( $var, static::transform( $item, $args ) );
    }
    return $var;
  }

  public static function transform(Model $item, $args = [ ]) { }
}

The transformer is being used for all the output everywhere, and each model has it's own Transformer, it's the first time it's having issues

And the transformer works if I don't paginate it (what you can see in first post)

I was messing around with this yesterday. I don't think you can have limit and paginator on the same query. I think it is either one. When I added limit it started loading the collection class.

For your paginated output, you are passing the Paginator object instead of the collection:

echo 'Second ouptut';
$limit = Input::get( 'limit', '5' );
$chats = Auth::User()->Chats()->paginate( $limit );
var_dump(ChatTransformer::transformCollection($chats));

Maybe try it this way:

echo 'Second ouptut';
$limit = Input::get( 'limit', '5' );
$chats = Auth::User()->Chats()->paginate( $limit );
var_dump(ChatTransformer::transformCollection($chats->getCollection()));

Source: http://laravel.com/api/4.1/Illuminate/Pagination/Paginator.html#method_getCollection

Believe it or not it just started working today, didn't change anything. But now it's showing as it should.

Thanks for the help anyway!