PHP HELP

Function for truncate a text containing html tags

Calling the function
$content = “Some String”;
$length = 5;
//Parameter $content is string content
//Parameter $length is string length to truncate
echo truncate($content,$length);

Function Definition

//Function for truncate a text containing html tags
function truncate($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 (f.e. <br/>)
if (preg_match(‘/^<(\s*.+?\/\s*|\s*(img|br|input|hr|area|base|basefont|col|frame|isindex|link|meta|param)(\s.+?)?)>$/is’, $line_matchings[1])) {
// do nothing
// if tag is a closing tag (f.e. </b>)
} else if (preg_match(‘/^<\s*\/([^\s]+?)\s*>$/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 (f.e. <b>)
} 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;
}