How can I paginate a merged collection in Laravel

Question

I am creating a stream which contains two types of objects, BluePerson and RedPerson. To create the stream, I fetch all of both objects, then merge them into one collection. After doing so, I need to paginate them, however paginate is for eloquent models and DB queries, and not collections, it seems. I have seen a lot about manually creating a paginator, but the documentation, especially in the API is sparse (I can't even seem to find the arguments the Paginator class accepts.)

How can I paginate the results of merging my collections?

public function index()
{
    $bluePerson = BluePerson::all();
    $redPerson = RedPerson::all();

    $people = $bluePerson->merge($redPerson)->sortByDesc('created_at');


    return view('stream.index')->with('people', $people);
}

Answer 1

You might try paginating both sets and merging them. You can find more information about pagination in the docs and the api. Here is an example of manually creating your own paginator...

$perPage = 20;
$blue = BluePerson::paginate($perPage / 2);
$red = RedPerson::paginate($perPage - count($blue));
$people = PaginationMerger::merge($blue, $red);

I have included the PaginationMerger class below.

use Illuminate\Pagination\LengthAwarePaginator;

class PaginationMerger
{
    /**
     * Merges two pagination instances
     *
     * @param  Illuminate\Pagination\LengthAwarePaginator $collection1
     * @param  Illuminate\Pagination\LengthAwarePaginator $collection2
     * @return Illuminate\Pagination\LengthAwarePaginator
     */
    static public function merge(LengthAwarePaginator $collection1, LengthAwarePaginator $collection2)
    {
        $total = $collection1->total() + $collection2->total();

        $perPage = $collection1->perPage() + $collection2->perPage();

        $items = array_merge($collection1->items(), $collection2->items());

        $paginator = new LengthAwarePaginator($items, $total, $perPage);

        return $paginator;
    }
}