*
* Licensed under MIT, see LICENSE.
*/
declare(strict_types=1);
namespace Grav\Plugin\PageToc;
use ArrayIterator;
use DOMDocument;
use DomElement;
use DOMXPath;
/**
* Trait that helps with HTML-related operations
*
* @package TOC
*/
trait HtmlHelper
{
protected function getHTMLParser($markup)
{
libxml_use_internal_errors(true);
$domDocument = new \DOMDocument();
$html = "$markup";
$domDocument->loadHTML(mb_encode_numericentity($html, [0x80, 0x10FFFF, 0, ~0], 'UTF-8'), LIBXML_HTML_NOIMPLIED | LIBXML_HTML_NODEFDTD);
$domDocument->preserveWhiteSpace = true;
return $domDocument;
}
/**
* Convert a topLevel and depth to H1..H6 tags array
*
* @param int $topLevel
* @param int $depth
* @return array|string[] Array of header tags; ex: ['h1', 'h2', 'h3']
*/
protected function determineHeaderTags(int $topLevel, int $depth): array
{
$desired = range((int) $topLevel, (int) $topLevel + ((int) $depth - 1));
$allowed = [1, 2, 3, 4, 5, 6];
return array_map(function ($val) {
return 'h' . $val;
}, array_intersect($desired, $allowed));
}
/**
* Traverse Header Tags in DOM Document
*
* @param DOMDocument $domDocument
* @param int $topLevel
* @param int $depth
* @return ArrayIterator
*/
protected function traverseHeaderTags(DOMDocument $domDocument, int $topLevel, int $depth): ArrayIterator
{
$xQueryResults = new DOMXPath($domDocument);
$xpathQuery = sprintf(
"//*[%s]",
implode(' or ', array_map(function ($v) {
return sprintf('local-name() = "%s"', $v);
}, $this->determineHeaderTags($topLevel, $depth)))
);
$nodes = [];
$xQueryResults = $xQueryResults->query($xpathQuery);
if ($xQueryResults) {
foreach ($xQueryResults as $node) {
$nodes[] = $node;
}
return new ArrayIterator($nodes);
} else {
return new ArrayIterator([]);
}
}
}