Truncate string but keep full html tag content

[londres9b]

Hi, I have this nice function to truncate a string with HTML.
It's very good only now I ran into a problem.

There are cases where for example The input will be this:
<a href="some url">this is a link</a>
and what I want to output is exactly the same, even if it it's bigger than the maximum length specified.

In other words, inside html tags it can't cut.

Can someone help me, please?
I've searched for a solution and thought about it for quite some time..

<?php
/**
 * truncateHtml can truncate a string up to a number of characters while preserving whole words and HTML tags
 *
 * @param string $text String to truncate.
 * @param integer $length Length of returned string, including ellipsis.
 * @param string $ending Ending to be appended to the trimmed string.
 * @param boolean $exact If false, $text will not be cut mid-word
 * @param boolean $considerHtml If true, HTML tags would be handled correctly
 *
 * @return string Trimmed string.
 */
function truncateHtml($text, $length = 100, $ending = '...', $exact = false, $considerHtml = true) {
	if ($considerHtml) {
		// if the plain text is shorter than the maximum length, return the whole text
		if (strlen(preg_replace('/<.*?>/', '', $text)) <= $length) {
			return $text;
		}
		// splits all html-tags to scanable lines
		preg_match_all('/(<.+?>)?([^<>]*)/s', $text, $lines, PREG_SET_ORDER);
		$total_length = strlen($ending);
		$open_tags = array();
		$truncate = '';
		foreach ($lines as $line_matchings) {
			// if there is any html-tag in this line, handle it and add it (uncounted) to the output
			if (!empty($line_matchings[1])) {
				// if it's an "empty element" with or without xhtml-conform closing slash
				if (preg_match('/^<(\s*.+?\/\s*|\s*(img|br|input|hr|area|base|basefont|col|frame|isindex|link|meta|param)(\s.+?)?)>$/is', $line_matchings[1])) {
					// do nothing
				// if tag is a closing tag
				} else if (preg_match('/^<\s*\/([^\s]+?)\s*>$/s', $line_matchings[1], $tag_matchings)) {
					// delete tag from $open_tags list
					$pos = array_search($tag_matchings[1], $open_tags);
					if ($pos !== false) {
					unset($open_tags[$pos]);
					}
				// if tag is an opening tag
				} else if (preg_match('/^<\s*([^\s>!]+).*?>$/s', $line_matchings[1], $tag_matchings)) {
					// add tag to the beginning of $open_tags list
					array_unshift($open_tags, strtolower($tag_matchings[1]));
				}
				// add html-tag to $truncate'd text
				$truncate .= $line_matchings[1];
			}
			// calculate the length of the plain text part of the line; handle entities as one character
			$content_length = strlen(preg_replace('/&[0-9a-z]{2,8};|&#[0-9]{1,7};|[0-9a-f]{1,6};/i', ' ', $line_matchings[2]));
			if ($total_length+$content_length> $length) {
				// the number of characters which are left
				$left = $length - $total_length;
				$entities_length = 0;
				// search for html entities
				if (preg_match_all('/&[0-9a-z]{2,8};|&#[0-9]{1,7};|[0-9a-f]{1,6};/i', $line_matchings[2], $entities, PREG_OFFSET_CAPTURE)) {
					// calculate the real length of all entities in the legal range
					foreach ($entities[0] as $entity) {
						if ($entity[1]+1-$entities_length <= $left) {
							$left--;
							$entities_length += strlen($entity[0]);
						} else {
							// no more characters left
							break;
						}
					}
				}
				$truncate .= substr($line_matchings[2], 0, $left+$entities_length);
				// maximum lenght is reached, so get off the loop
				break;
			} else {
				$truncate .= $line_matchings[2];
				$total_length += $content_length;
			}
			// if the maximum length is reached, get off the loop
			if($total_length>= $length) {
				break;
			}
		}
	} else {
		if (strlen($text) <= $length) {
			return $text;
		} else {
			$truncate = substr($text, 0, $length - strlen($ending));
		}
	}
	// if the words shouldn't be cut in the middle...
	if (!$exact) {
		// ...search the last occurance of a space...
		$spacepos = strrpos($truncate, ' ');
		if (isset($spacepos)) {
			// ...and cut the text in this position
			$truncate = substr($truncate, 0, $spacepos);
		}
	}
	// add the defined ending to the text
	$truncate .= $ending;
	if($considerHtml) {
		// close all unclosed html-tags
		foreach ($open_tags as $tag) {
			$truncate .= '</' . $tag . '>';
		}
	}
	return $truncate;
}
 
?>

[Luuk]

This cannnot be done, because everything is inside the HTML-tag 'html'.....