How can I paginate an array of objects in Laravel?

Question

I'm building an application using Laravel 4.2. I have a model for units and another for users and pivot table user_units. Every user in this application can select a unit and add it to his favorite list then he can publish this unit with his information as an ad.

I want to select all units published by all users

The user_units (pivot) table has the following columns:

id   
user_id 
unit_id 
publish      
adtype       
addinfo          
created_at  
updated_at

With relations methods on models

public function users() {
    return $this->belongsToMany('User', 'user_units')
                ->withPivot('id','publish', 'adtype', 'addinfo');
}

public function units() {
    return $this->belongsToMany('Unit', 'user_units')
                ->withPivot('id','publish', 'adtype', 'addinfo');
}

My query to select all published units by all users

// Get all published units by users for sale. 
    $users = User::all();
    $publishedSaleUnits = [];
    foreach($users as $user){
        $userUnits = $user->units()->orderBy('adtype', 'desc')->get();
        if(count($userUnits)){
            foreach($userUnits as $unit){
                if($unit->pivot->publish == 1 && $unit->unit_purpose_id == 1){
                    if( $unit->pivot->adtype ){
                        //push all featured ads onto the beginning of array
                        array_unshift($publishedSaleUnits, $unit);
                    }else{
                        //push all normal ads onto the end of array
                        array_push($publishedSaleUnits, $unit);
                    }
                }
            }
        }
    }

Now I got the result but I can't use pagination with results because it's an array of objects.

So is there any better solution to get all published units by user with pagination?

Answer 1

according to this article https://www.itsolutionstuff.com/post/how-to-create-pagination-from-array-in-laravelexample.html

you can paginate your array by creating a custom method and using LengthAwarePaginator

namespace App\Http\Controllers;
  
use Illuminate\Http\Request;
use Illuminate\Pagination\Paginator;
use Illuminate\Support\Collection;
use Illuminate\Pagination\LengthAwarePaginator;
  
class PaginationController extends Controller
{
    public function index()
    {
        $myArray = [
            ['id'=>1, 'title'=>'Laravel CRUD'],
            ['id'=>2, 'title'=>'Laravel Ajax CRUD'],
            ['id'=>3, 'title'=>'Laravel CORS Middleware'],
        ];
  
        $data = $this->paginate($myArray);
        return view('paginate', compact('data'));
    }
   
    public function paginate($items, $perPage = 5, $page = null, $options = [])
    {
        $page = $page ?: (Paginator::resolveCurrentPage() ?: 1);
        $items = $items instanceof Collection ? $items : Collection::make($items);
        return new LengthAwarePaginator($items->forPage($page, $perPage), $items->count(), $perPage, $page, $options);
    }
}

Answer 2

Your approach to query the data is extremely inefficient. Fetch your data in one query. Nested traversing is not only hard to read but also a performance killer.

To the pagination problem:

Laravel provides a Pagignator Factory. With it you will be able to build your own Paginator with your own data.

It's as easy as

$units = Paginator::make($unit, count($unit), 10);

if you're using the Facade. Otherwise Illuminate\Pagination\Factory is the class you are looking for.