pagenavigation.php

См. документацию.

<?php
namespace Bitrix\Main\UI;
 
use Bitrix\Main\Web;

class PageNavigation
{
    protected $id;
    protected $pageSizes = array();
    protected $pageSize = 20;
    protected $recordCount;
    protected $currentPage;
    protected $allowAll = false;
    protected $allRecords = false;

    public function __construct(string $id)
    {
        $this->id = $id;
    }

    public function initFromUri()
    {
        $navParams = [];
 
        $request = \Bitrix\Main\Context::getCurrent()->getRequest();
 
        if(($value = $request->getQuery($this->id)) !== null)
        {
            if (is_string($value))
            {
                //parameters are in the QUERY_STRING
                $params = explode("-", $value);
                for($i = 0, $n = count($params); $i < $n; $i += 2)
                {
                    $navParams[$params[$i]] = $params[$i+1];
                }
            }
        }
        else
        {
            //probably parametrs are in the SEF URI
            $matches = [];
            if(preg_match("'/".preg_quote($this->id, "'")."/page-([\\d]+|all)+(/size-([\\d]+))?'", $request->getRequestUri(), $matches))
            {
                $navParams["page"] = $matches[1];
                if(isset($matches[3]))
                {
                    $navParams["size"] = $matches[3];
                }
            }
        }
 
        if(isset($navParams["size"]))
        {
            //set page size from user request
            if(in_array($navParams["size"], $this->pageSizes))
            {
                $this->setPageSize((int)$navParams["size"]);
            }
        }
 
        if(isset($navParams["page"]))
        {
            if($navParams["page"] == "all" && $this->allowAll == true)
            {
                //show all records in one page
                $this->allRecords = true;
            }
            else
            {
                //set current page within boundaries
                $currentPage = (int)$navParams["page"];
                if($currentPage >= 1)
                {
                    if($this->recordCount !== null)
                    {
                        $maxPage = $this->getPageCount();
                        if($currentPage > $maxPage)
                        {
                            $currentPage = $maxPage;
                        }
                    }
                    $this->setCurrentPage($currentPage);
                }
            }
        }
    }

    public function getPageCount()
    {
        if($this->allRecords)
        {
            return 1;
        }
        $maxPages = (int)floor($this->recordCount/$this->pageSize);
        if(($this->recordCount % $this->pageSize) > 0)
        {
            $maxPages++;
        }
        return $maxPages;
    }

    public function setPageSize($n)
    {
        $this->pageSize = (int)$n;
        return $this;
    }

    public function setCurrentPage($n)
    {
        $this->currentPage = (int)$n;
        return $this;
    }

    public function getCurrentPage()
    {
        if($this->currentPage !== null)
        {
            return $this->currentPage;
        }
        return 1;
    }

    public function allowAllRecords($mode)
    {
        $this->allowAll = (bool)$mode;
        return $this;
    }

    public function setRecordCount($n)
    {
        $this->recordCount = (int)$n;
        return $this;
    }

    public function getRecordCount()
    {
        return $this->recordCount;
    }

    public function setPageSizes(array $sizes)
    {
        $this->pageSizes = $sizes;
        return $this;
    }

    public function getPageSizes()
    {
        return $this->pageSizes;
    }

    public function getPageSize()
    {
        return $this->pageSize;
    }

    public function getId()
    {
        return $this->id;
    }

    public function getOffset()
    {
        if($this->allRecords)
        {
            return 0;
        }
        return ($this->getCurrentPage() - 1) * $this->pageSize;
    }

    public function getLimit()
    {
        if($this->allRecords)
        {
            return $this->getRecordCount();
        }
        return $this->pageSize;
    }

    public function allRecordsShown()
    {
        return $this->allRecords;
    }

    public function allRecordsAllowed()
    {
        return $this->allowAll;
    }

    public function addParams(Web\Uri $uri, $sef, $page, $size = null)
    {
        if($sef == true)
        {
            $this->clearParams($uri, $sef);
 
            $path = $uri->getPath();
            $pos = mb_strrpos($path, "/");
            $path = mb_substr($path, 0, $pos + 1).$this->id."/page-".$page."/".($size !== null? "size-".$size."/" : '').mb_substr($path, $pos + 1);
            $uri->setPath($path);
        }
        else
        {
            $uri->addParams(array($this->id => "page-".$page.($size !== null? "-size-".$size : '')));
        }
        return $uri;
    }

    public function clearParams(Web\Uri $uri, $sef)
    {
        if($sef == true)
        {
            $path = $uri->getPath();
            $path = preg_replace("'/".preg_quote($this->id, "'")."/page-([\\d]+|all)+(/size-([\\d]+))?'", "", $path);
            $uri->setPath($path);
        }
        else
        {
            $uri->deleteParams(array($this->id));
        }
        return $uri;
    }
}