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

I did in JS, hope this logic will help in PHP too..

splitText : function(content, count){
        var originalContent = content;
         content = content.substring(0, count);
          //If there is no occurance of matches before breaking point and the hit breakes in between html tags.
         if (content.lastIndexOf("<") > content.lastIndexOf(">")){
            content = content.substring(0, content.lastIndexOf('<'));
            count = content.length;
            if(originalContent.indexOf("</", count)!=-1){
                content += originalContent.substring(count, originalContent.indexOf('>', originalContent.indexOf("</", count))+1);
            }else{
                 content += originalContent.substring(count, originalContent.indexOf('>', count)+1);
            }
          //If the breaking point is in between tags.
         }else if(content.lastIndexOf("<") != content.lastIndexOf("</")){
            content = originalContent.substring(0, originalContent.indexOf('>', count)+1);
         }
        return content;
    },

Hope this logic helps some one..

Answer 2

This should do it:

class Html
{
    protected
        $reachedLimit = false,
        $totalLen = 0,
        $maxLen = 25,
        $toRemove = array();

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

        $dom = new DomDocument();

        if (version_compare(PHP_VERSION, '5.4.0') < 0) {
            $dom->loadHTML($html);
        } else {
            $dom->loadHTML($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);
        }

        // remove wrapper tags added by DD (doctype, html...)
        if (version_compare(PHP_VERSION, '5.4.0') < 0) {
            // http://stackoverflow.com/a/6953808/1058140
            $dom->removeChild($dom->firstChild);
            $dom->replaceChild($dom->firstChild->firstChild->firstChild, $dom->firstChild);

            return $dom->saveHTML();
        }

        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 += $nodeLen = strlen($node->nodeValue);

                // use mb_strlen / mb_substr for UTF-8 support
                if ($this->totalLen > $maxLen) {
                    $node->nodeValue = substr($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;
    }
}

Use like: $str = Html::trim($str, 236);

(demo here)

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Some performance comparisons between this and cakePHP's regex solution

There's very little difference, and at very large string sizes, DomDocument is actually faster. Reliability is more important than saving a few microseconds in my opinion.