surveyor_indonesia_backend/app/Models/ReportActivityMaterial.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;
use App\Models\Activity;
use App\Models\AssignMaterial;

class ReportActivityMaterial extends Model
{
	protected $table = 'report_activity_material';

	const CREATED_AT = 'created_at';
	const UPDATED_AT = 'updated_at';

	protected $fillable = [
		'activity_id', 'user_id', 'qty', 'lat', 'lon','assign_material_id',
		'report_date', 'description', 'created_at', 'created_by', 'updated_at', 'updated_by'
	];

	public static function boot() {
		parent::boot();

		static::created(function($data) {

			$activity = Activity::find($data->activity_id);
			$assignedMaterial = AssignMaterial::find($data->assign_material_id);

			$activity->biaya_actual += floatval($assignedMaterial->budget) * floatval($data->qty);
			$activity->save();

		});

		static::deleted(function($data) {

			$activity = Activity::find($data->activity_id);
			$assignedMaterial = AssignMaterial::find($data->assign_material_id);

			$activity->biaya_actual -= floatval($assignedMaterial->budget) * floatval($data->qty);
			$activity->save();

		});

	}
}