Shortening text tweet-like without cutting links inside - php

Question

I've got a string like this:
I love #kevinrose 's new website Link
And I have this function:
function short($string, $max = 255) {
if (strlen($string) >= $max) {
$string = mb_substr($string, 0, $max - 5, 'utf-8') . '...';
} return $string;
}
If I cut the screen at 50, it will end up being something that :
I love #kevinrose 's new website <a href="http://kevinr...
Which will of course kill the html.
Is there an easy way I can avoid cutting the a href tag (before or preferably after) without breaking the HTML ?
I need to keep my tags of course.
Thank you

Answer 1

see this from PHP: Truncate string while preserving HTML tags and whole words - Alan Whipple -> http://alanwhipple.com/2011/05/25/php-truncate-string-preserving-html-tags-words/
<?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;
}
?>
also see here
Truncating Text & HTML with PHP | Patrick Galbraith ->
http://www.pjgalbraith.com/2011/11/truncating-text-html-with-php/

Answer 2

Here's a bit shorter method. It doesn't walk the DOM tree, but it will work for nearly all situations.
This method first strips all html tags from the content (so html tags won't be counted towards the string length either). Then, if the string needs to be truncated, it truncates it and re-inserts all html tags.
<?php
function short($string, $max = 255) {
preg_match_all('/<[^>]+>/', $string, $tags); // Save tag information for later
$stripped = preg_replace('/<[^>]+>/', '', $string); // Strip html tags
// Truncate the string if needed
if (strlen($stripped) > $max) {
$truncated = mb_substr($stripped, 0, $max, 'utf-8');
// Insert html tags, if any
if (sizeof($tags) > 0) {
$pos = 0;
foreach ($tags[0] as $tag) {
$pos += strpos($string, $tag); // Get the position the tag should be inserted at
$string = substr($string, $pos); // Shift to avoid issues with duplicate tags
$truncated = substr_replace($truncated, $tag, $pos, 0); // Insert the tag
}
}
$string = $truncated . '…';
}
return $string;
}
echo short('I love #kevinrose\'s new website Link. Here is a bit of additional text after the link.<a></a>', 50);