Shorten text without splitting words or breaking html tags

Question

I am trying to cut off text after 236 chars without cutting words in half and preserving html tags. This is what I am using right now:

$shortdesc = $_helper-         


        

Answer 1

This will work with Unicode (from @nice ass answer):

class Html
{
    protected
        $reachedLimit = false,
        $totalLen = 0,
        $maxLen = 25,
        $toRemove = [];

    public static function trim($html, $maxLen = 25)
    {

        $dom = new \DOMDocument();
        $dom->loadHTML('' . $html, LIBXML_HTML_NOIMPLIED | LIBXML_HTML_NODEFDTD);

        $instance = new static();
        $toRemove = $instance->walk($dom, $maxLen);

        // remove any nodes that exceed limit
        foreach ($toRemove as $child) {
            $child->parentNode->removeChild($child);
        }

        return $dom->saveHTML();
    }

    protected function walk(\DOMNode $node, $maxLen)
    {

        if ($this->reachedLimit) {
            $this->toRemove[] = $node;
        } else {
            // only text nodes should have text,
            // so do the splitting here
            if ($node instanceof \DOMText) {
                $this->totalLen += $nodeLen = mb_strlen($node->nodeValue);

                // use mb_strlen / mb_substr for UTF-8 support
                if ($this->totalLen > $maxLen) {
                    dump($node->nodeValue);
                    $node->nodeValue = mb_substr($node->nodeValue, 0, $nodeLen - ($this->totalLen - $maxLen)) . '...';
                    $this->reachedLimit = true;
                }
            }

            // if node has children, walk its child elements
            if (isset($node->childNodes)) {
                foreach ($node->childNodes as $child) {
                    $this->walk($child, $maxLen);
                }
            }
        }

        return $this->toRemove;
    }
}