Symfony DOMCrawler: How to change html?

Question

How to edit html of elements? I tried this, but i get this error.

Fatal error: Uncaught InvalidArgumentException: Attaching DOM nodes from multiple documents in the same crawler is forbidden.

$crawler = new Crawler('<h1>The title</h1>');
$crawler
    ->filter('h1,h2,h3,h4,h5,h6')
    ->each(function (Crawler $crawler, $i) use (&$replace) {
        $crawler->html('<span>test</span>' . $crawler->html());
    });

Answer 1

Use this:

$doc = new DOMDocument;
$doc->loadHTML($html);
$crawler = new Crawler($doc);

$crawler
    ->filter('h1,h2,h3,h4,h5,h6')
    ->each(function (Crawler $crawler) use ($doc) {
        foreach ($crawler as $node) {
            $span = $doc->createElement('span', 'test');
            $node->parentNode->insertBefore($span, $node);
        }
    });

Important: Use same DOMDocument object for creating new tag that used in Crawler object.

As explained in The DomCrawler Component docs:

An instance of the Crawler represents a set of DOMElement objects, which are nodes that can be traversed...

So, you need to traverse Crawler object before manipulate DOMElements.