filtercontrollerfactory.php

<?php
 
namespace Bitrix\Main\Access\Filter\Factory;
 
use Bitrix\Main\Access\AccessibleController;
use Bitrix\Main\Access\Filter\AccessFilter;
use Bitrix\Main\Access\Filter\FilterFactory;
use ReflectionClass;
 
class FilterControllerFactory implements FilterFactory
{
    protected const SUFFIX = 'Filter';
 
    public function createFromAction(string $action, AccessibleController $controller): ?AccessFilter
    {
        $className = $this->getClassName($action, $controller);
        if (!$className  || !class_exists($className ))
        {
            return null;
        }
 
        $ref = new ReflectionClass($className);
        if ($ref->implementsInterface(AccessFilter::class))
        {
            return $ref->newInstance($controller);
        }
 
        return null;
    }
 
    protected function getClassName(string $action, AccessibleController $controller): ?string
    {
        $action = explode('_', $action);
        $action = array_map(fn($el) => ucfirst(mb_strtolower($el)), $action);
 
        return $this->getNamespace($controller) . implode($action) . static::SUFFIX;
    }
 
    protected function getNamespace(AccessibleController $controller): string
    {
        $class = new \ReflectionClass($controller);
        $namespace = $class->getNamespaceName();
 
        return $namespace.'\\'.static::SUFFIX.'\\';
    }
}