pagenavigation.php

См. документацию.

<?php
 
namespace Bitrix\Sender\UI;
 
use Bitrix\Main\Application;
use Bitrix\Main\UI;

class PageNavigation extends UI\PageNavigation
{
    protected $sessionKeyName = 'sender_page_navigation';

    public function resetSessionVar()
    {
        if(isset($_SESSION[$this->sessionKeyName]))
        {
            unset($_SESSION[$this->sessionKeyName]);
        }
    }
 
    protected function setSessionVar($page = 1, $allRecords=false)
    {
        if(!isset($_SESSION[$this->sessionKeyName]))
        {
            $_SESSION[$this->sessionKeyName] = array();
        }
 
        $_SESSION[$this->sessionKeyName][$this->id] = [
            'page' => $page,
            'allRecords' => $allRecords
        ];
    }
 
    protected function getSessionVar()
    {
        if(!isset($_SESSION[$this->sessionKeyName]))
        {
            return 1;
        }
 
        if (!isset($_SESSION[$this->sessionKeyName][$this->id]))
        {
            return 1;
        }
 
        return $_SESSION[$this->sessionKeyName][$this->id];
    }

    public function initFromUri()
    {
        parent::initFromUri();
 
        $page = $this->currentPage;
        $request = Application::getInstance()->getContext()->getRequest();
        if ($request->get('apply_filter') === 'Y')
        {
            $page = 1;
        }
        if (!$page && $request->get('grid_action') === 'pagination')
        {
            $page = 1;
        }
 
        if ($page > 0)
        {
            $this->setSessionVar($page, $this->allRecords);
        }
        else
        {
            $page = is_array($this->getSessionVar()) ? ($this->getSessionVar()['page'] ?? 0) : 0;
        }
 
        $page = $page > 0 ? $page : 1;
        $this->setCurrentPage($page);
        $this->allRecords = is_array($this->getSessionVar()) ? ($this->getSessionVar()['allRecords'] ?? false) : false;
    }
}