baoshi-was/app/Events/DeliveryAppointmentEvent.php

<?php

namespace App\Events;

use App\DeliveryAppointmentCar;
use Illuminate\Broadcasting\Channel;
use Illuminate\Contracts\Broadcasting\ShouldBroadcast;
use Illuminate\Database\Eloquent\Builder;
use Illuminate\Foundation\Events\Dispatchable;
use Illuminate\Queue\SerializesModels;

class DeliveryAppointmentEvent implements ShouldBroadcast
{
    use Dispatchable, SerializesModels;

    public $delivery;
    /**
     * Create a new event instance.
     *
     * @param DeliveryAppointmentCar|\stdClass $delivery
     *
     * @return void
     */
    public function __construct(DeliveryAppointmentCar $delivery)
    {
        $delivery->load(["deliveryAppointment"=>function($query){
            /** @var Builder $query */
            $query->withCount("cars");
        }]);
        $count = $delivery->deliveryAppointment->cars_count ?? 0;
        $delivery->warehouse = $delivery->deliveryAppointment->warehouse_id ?? "";
        $delivery->cubic_meter = isset($delivery->deliveryAppointment->cubic_meter) ? ($count>1 ? $delivery->deliveryAppointment->cubic_meter."/".$count : $delivery->deliveryAppointment->cubic_meter) : "";
        $delivery->tonne = isset($delivery->deliveryAppointment->tonne) ? ($count>1 ? $delivery->deliveryAppointment->tonne."/".$count : $delivery->deliveryAppointment->tonne) : "";
        $this->delivery = $delivery->withoutRelations();
    }

    /**
     * Get the channels the event should broadcast on.
     *
     * @return \Illuminate\Broadcasting\Channel|array
     */
    public function broadcastOn()
    {
        return new Channel('delivery');
    }

    public function broadcastAs()
    {
        return "car";
    }
}