/** * truncate_html() * * Truncates a HTML string to a given length of _visisble_ (content) characters. * E.g. * "This is some bold text" has a visible/content length of 22 characters, * though the total string length is 29 characters. * This function allows you to limit the visible/content length whilst preserving any HTML formatting. * * @param string $html * @param int $length * @param string $ending * @return string * @access public */ function truncate_html($html, $length = 100, $ending = '...') { if (!is_string($html)) { trigger_error('Function \'truncate_html\' expects argument 1 to be an string', E_USER_ERROR); return false; } if (mb_strlen(strip_tags($html)) <= $length) { return $html; } $total = mb_strlen($ending); $open_tags = array(); $return = ''; $finished = false; $final_segment = ''; $self_closing_elements = array( 'area', 'base', 'br', 'col', 'frame', 'hr', 'img', 'input', 'link', 'meta', 'param' ); $inline_containers = array( 'a', 'b', 'abbr', 'cite', 'em', 'i', 'kbd', 'span', 'strong', 'sub', 'sup' ); while (!$finished) { if (preg_match('/^<(\w+)[^>]*>/', $html, $matches)) { // Does the remaining string start in an opening tag? // If not self-closing, place tag in $open_tags array: if (!in_array($matches[1], $self_closing_elements)) { $open_tags[] = $matches[1]; } // Remove tag from $html: $html = substr_replace($html, '', 0, strlen($matches[0])); // Add tag to $return: $return .= $matches[0]; } elseif (preg_match('/^<\/(\w+)>/', $html, $matches)) { // Does the remaining string start in an end tag? // Remove matching opening tag from $open_tags array: $key = array_search($matches[1], $open_tags); if ($key !== false) { unset($open_tags[$key]); } // Remove tag from $html: $html = substr_replace($html, '', 0, strlen($matches[0])); // Add tag to $return: $return .= $matches[0]; } else { // Extract text up to next tag as $segment: if (preg_match('/^([^<]+)(<\/?(\w+)[^>]*>)?/', $html, $matches)) { $segment = $matches[1]; // Following code taken from https://trac.cakephp.org/browser/tags/1.2.1.8004/cake/libs/view/helpers/text.php?rev=8005. // Not 100% sure about it, but assume it deals with utf and html entities/multi-byte characters to get accureate string length. $segment_length = mb_strlen(preg_replace('/&[0-9a-z]{2,8};|&#[0-9]{1,7};|&#x[0-9a-f]{1,6};/i', ' ', $segment)); // Compare $segment_length + $total to $length: if ($segment_length + $total > $length) { // Truncate $segment and set as $final_segment: $remainder = $length - $total; $entities_length = 0; if (preg_match_all('/&[0-9a-z]{2,8};|&#[0-9]{1,7};|&#x[0-9a-f]{1,6};/i', $segment, $entities, PREG_OFFSET_CAPTURE)) { foreach($entities[0] as $entity) { if ($entity[1] + 1 - $entities_length <= $remainder) { $remainder--; $entities_length += mb_strlen($entity[0]); } else { break; } } } // Otherwise truncate $segment and set as $final_segment: $finished = true; $final_segment = mb_substr($segment, 0, $remainder + $entities_length); } else { // Add $segment to $return and increase $total: $return .= $segment; $total += $segment_length; // Remove $segment from $html: $html = substr_replace($html, '', 0, strlen($segment)); } } else { $finshed = true; } } } // Check for spaces in $final_segment: if (strpos($final_segment, ' ') === false && preg_match('/<(\w+)[^>]*>$/', $return)) { // If none and $return ends in an opening tag: (we ignore $final_segment) // Remove opening tag from end of $return: $return = preg_replace('/<(\w+)[^>]*>$/', '', $return); // Remove opening tag from $open_tags: $key = array_search($matches[3], $open_tags); if ($key !== false) { unset($open_tags[$key]); } } else { // Otherwise, truncate $final_segment to last space and add to $return: // $spacepos = strrpos($final_segment, ' '); $return .= mb_substr($final_segment, 0, mb_strrpos($final_segment, ' ')); } $return = trim($return); $len = strlen($return); $last_char = substr($return, $len - 1, 1); if (!preg_match('/[a-zA-Z0-9]/', $last_char)) { $return = substr_replace($return, '', $len - 1, 1); } // Add closing tags: $closing_tags = array_reverse($open_tags); $ending_added = false; foreach($closing_tags as $tag) { if (!in_array($tag, $inline_containers) && !$ending_added) { $return .= $ending; $ending_added = true; } $return .= ''; } return $return; }

Karun Shakya karunshakya