AbstractPaginator.php

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<?php
 
declare(strict_types=1);
 
/*
 * This file is part of the TYPO3 CMS project.
 *
 * It is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License, either version 2
 * of the License, or any later version.
 *
 * For the full copyright and license information, please read the
 * LICENSE.txt file that was distributed with this source code.
 *
 * The TYPO3 project - inspiring people to share!
 */
 
namespace ‪TYPO3\CMS\Core\Pagination;
 
abstract class ‪AbstractPaginator implements ‪PaginatorInterface
{
    protected ‪$numberOfPages = 1;
 
    protected ‪$keyOfFirstPaginatedItem = 0;
 
    protected ‪$keyOfLastPaginatedItem = 0;
 
    private ‪$currentPageNumber = 1;
 
    private ‪$itemsPerPage = 10;
 
    public function ‪withItemsPerPage(int ‪$itemsPerPage): ‪PaginatorInterface
    {
        if (‪$itemsPerPage === $this->itemsPerPage) {
            return $this;
        }
 
        $new = clone $this;
        $new->setItemsPerPage(‪$itemsPerPage);
        $new->updateInternalState();
 
        return $new;
    }
 
    public function ‪withCurrentPageNumber(int ‪$currentPageNumber): ‪PaginatorInterface
    {
        if (‪$currentPageNumber === $this->currentPageNumber) {
            return $this;
        }
 
        $new = clone $this;
        $new->setCurrentPageNumber(‪$currentPageNumber);
        $new->updateInternalState();
 
        return $new;
    }
 
    public function ‪getNumberOfPages(): int
    {
        return ‪$this->numberOfPages;
    }
 
    public function ‪getCurrentPageNumber(): int
    {
        return ‪$this->currentPageNumber;
    }
 
    public function ‪getKeyOfFirstPaginatedItem(): int
    {
        return ‪$this->keyOfFirstPaginatedItem;
    }
 
    public function ‪getKeyOfLastPaginatedItem(): int
    {
        return ‪$this->keyOfLastPaginatedItem;
    }
 
    abstract protected function ‪updatePaginatedItems(int ‪$itemsPerPage, int $offset): void;
 
    abstract protected function ‪getTotalAmountOfItems(): int;
 
    abstract protected function ‪getAmountOfItemsOnCurrentPage(): int;
 
    protected function ‪hasItemsOnCurrentPage(): bool
    {
        return $this->‪getAmountOfItemsOnCurrentPage() > 0;
    }
 
    protected function ‪updateInternalState(): void
    {
        $offset = (int)($this->itemsPerPage * ($this->currentPageNumber - 1));
        $totalAmountOfItems = $this->‪getTotalAmountOfItems();
 
        /*
         * If the total amount of items is zero, then the number of pages is mathematically zero as
         * well. As that looks strange in the frontend, the number of pages is forced to be at least
         * one.
         */
        $this->numberOfPages = max(1, (int)ceil($totalAmountOfItems / $this->itemsPerPage));
 
        /*
         * To prevent empty results in case the given current page number exceeds the maximum number
         * of pages, we set the current page number to the last page and update the internal state
         * with this value again. Such situation should in the first place be prevented by not allowing
         * those values to be passed, e.g. by using the "max" attribute in the view. However there are
         * valid cases. For example when a user deletes a record while the pagination is already visible
         * to another user with, until then, a valid "max" value. Passing invalid values unintentionally
         * should therefore just silently be resolved.
         */
        if ($this->currentPageNumber > $this->numberOfPages) {
            $this->currentPageNumber = ‪$this->numberOfPages;
            $this->‪updateInternalState();
            return;
        }
 
        $this->‪updatePaginatedItems($this->itemsPerPage, $offset);
 
        if (!$this->‪hasItemsOnCurrentPage()) {
            $this->keyOfFirstPaginatedItem = 0;
            $this->keyOfLastPaginatedItem = 0;
            return;
        }
 
        $indexOfLastPaginatedItem = min($offset + $this->itemsPerPage, $totalAmountOfItems);
 
        $this->keyOfFirstPaginatedItem = $offset;
        $this->keyOfLastPaginatedItem = $indexOfLastPaginatedItem - 1;
    }
 
    protected function ‪setItemsPerPage(int ‪$itemsPerPage): void
    {
        if (‪$itemsPerPage < 1) {
            throw new \InvalidArgumentException(
                'Argument $itemsPerPage must be greater than 0',
                1573061766
            );
        }
 
        $this->itemsPerPage = ‪$itemsPerPage;
    }
 
    protected function ‪setCurrentPageNumber(int ‪$currentPageNumber): void
    {
        if (‪$currentPageNumber < 1) {
            throw new \InvalidArgumentException(
                'Argument $currentPageNumber must be greater than 0',
                1573047338
            );
        }
 
        $this->currentPageNumber = ‪$currentPageNumber;
    }
}