private function checkPdfColumns($book, CheckLinks &$check_links)
{
$pdfs_only_book = Books::pdfsOnlyList($book);
$book_count = 1;
for ($i = 0; $i < count($pdfs_only_book); $i = $i + Books::$COLUMNS_OF_PDF_IN_BOOK) {
$index_pdf_location = $i;
$index_pdf_pages = $i + 1;
$index_pdf_info = $i + 2;
$pdf_location = $pdfs_only_book[$index_pdf_location];
if (NULL === $pdf_location) {
break;
}
$this->checkPdfLink($pdf_location, "?-PDF Link {$book_count}");
$check_links->addUrl($pdf_location);
$pdf_pages = $pdfs_only_book[$index_pdf_pages];
$this->checkNumber($pdf_pages, "?-PDF Page Count {$book_count}");
if (isset($pdfs_only_book[$index_pdf_info])) {
$pdf_info = $pdfs_only_book[$index_pdf_info];
$this->checkCharacters($pdf_info, "?-PDF INFO {$book_count}");
}
++$book_count;
}
}
