Highlighting Text: How to echo HTML DOM element with all tags

I want to highlight specified keywords in the body of an HTML document. At first I used preg_replace to put a < span > around the keywords, but of course that caused problems if the keyword was part of a tag, like the letter "i" (as in < li >). So instead, I'm using DOM::loadHTMLFile(path) to load the document, and then use the preg_replace inside the values of each child.

So far, s开发者_如何学Goo good. I can echo out the plain text of the document with the appropriate words highlighted and no interference from tags. But I need to echo the entire body of the text including the tags after the changes, and I don't know how. Here's what I have so far:

if (file_exists('mss/'.$link_title)) {
        $descfile = DOMDocument::loadHTMLFile('mss/'.$link_title);
        foreach ($descfile->childNodes as $e) {
            $desc_output = $e->nodeValue;
            $desc_output = preg_replace($to_highlight, "<span class=\"highlight\">$0</span>", $desc_output);
            }
        echo ???
    }

What should I echo?

---

If you change your code to:

$e->nodeValue = preg_replace($to_highlight, "<span class=\"highlight\">$0</span>", $e->nodeValue);

You can probably use:

http://php.net/manual/de/domdocument.savehtml.php

to output your entire html document.