Aşağıdaki foreachta, ben anahtar kelime için $ node.TextContent ayrıştırmak ve çevresinde kalın etiketi sarmak gerekir. Bu DOM ile mümkün mü? Nasıl?

$myContent ="<h1>This word should not be replaced: TEST</h1>. But this one should be replaced: test";

$dom = new DOMDocument;
$dom->loadHTML(strtolower($myContent));
$xPath = new DOMXPath($dom);
foreach($xPath->query("//text()[contains(.,'test') and not(ancestor::h1)]") as $node)
    {
        /*need to do a replace on each occurrence of the word "test"
         in $node->textContent here so that it becomes <b>test</b>. How? */
    }

echo $dom->saveHTML vermelidir:

<h1>This word should not be replaced: TEST</h1>. 
But this one should be replaced: <b>test</b>"