meetup/app/Http/Controllers/Admin/AttenderCrudController.php

<?php

namespace App\Http\Controllers\Admin;

use App\Http\Requests\AttenderRequest;
use App\Models\Event;
use Backpack\CRUD\app\Http\Controllers\CrudController;
use Backpack\CRUD\app\Library\CrudPanel\CrudPanelFacade as CRUD;

/**
 * Class AttenderCrudController
 * @package App\Http\Controllers\Admin
 * @property-read \Backpack\CRUD\app\Library\CrudPanel\CrudPanel $crud
 */
class AttenderCrudController extends CrudController
{
    use \Backpack\CRUD\app\Http\Controllers\Operations\ListOperation;
    use \Backpack\CRUD\app\Http\Controllers\Operations\CreateOperation;
    use \Backpack\CRUD\app\Http\Controllers\Operations\UpdateOperation;
    use \Backpack\CRUD\app\Http\Controllers\Operations\DeleteOperation;
    use \Backpack\CRUD\app\Http\Controllers\Operations\ShowOperation;

    /**
     * Configure the CrudPanel object. Apply settings to all operations.
     *
     * @return void
     */
    public function setup()
    {
        CRUD::setModel(\App\Models\Attender::class);
        CRUD::setRoute(config('backpack.base.route_prefix') . '/attender');
        CRUD::setEntityNameStrings('attender', 'attenders');
    }

    /**
     * Define what happens when the List operation is loaded.
     *
     * @see  https://backpackforlaravel.com/docs/crud-operation-list-entries
     * @return void
     */
    protected function setupListOperation()
    {
        $this->crud->setFromDb();

        /**
         * Columns can be defined using the fluent syntax or array syntax:
         * - CRUD::column('price')->type('number');
         * - CRUD::addColumn(['name' => 'price', 'type' => 'number']);
         */
        $this->crud->addFilter([
            'name'  => 'events',
            'type'  => 'select2',
            'label' => "Event"
        ], function() {
            return Event::all()->pluck('name', 'id')->toArray();
        }, function($value) {
            $this->crud->query = $this->crud->query->whereHas('events', function ($query) use ($value) {
                $query->where('event_id', $value);
            });
        });
    }

    /**
     * Define what happens when the Create operation is loaded.
     *
     * @see https://backpackforlaravel.com/docs/crud-operation-create
     * @return void
     */
    protected function setupCreateOperation()
    {
        CRUD::setValidation(AttenderRequest::class);

        $this->crud->setFromDb();


        /**
         * Fields can be defined using the fluent syntax or array syntax:
         * - CRUD::field('price')->type('number');
         * - CRUD::addField(['name' => 'price', 'type' => 'number']));
         */
    }

    /**
     * Define what happens when the Update operation is loaded.
     *
     * @see https://backpackforlaravel.com/docs/crud-operation-update
     * @return void
     */
    protected function setupUpdateOperation()
    {
        $this->setupCreateOperation();
    }
}