*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
class Truncator {
public static $default_options = array(
'ellipsis' => '…',
'break' => ' ',
'length_in_chars' => false,
'word_safe' => false,
);
// These tags are allowed to have an ellipsis inside
public static $ellipsable_tags = array(
'p', 'ol', 'ul', 'li',
'div', 'header', 'article', 'nav',
'section', 'footer', 'aside',
'dd', 'dt', 'dl',
);
public static $self_closing_tags = array(
'br', 'hr', 'img',
);
/**
* Truncate given HTML string to specified length.
* If length_in_chars is false it's trimmed by number
* of words, otherwise by number of characters.
*
* @param string $html
* @param integer $length
* @param string|array $opts
* @return string
*/
public static function truncate($html, $length, $opts=array())
{
if (is_string($opts)) $opts = array('ellipsis' => $opts);
$opts = array_merge(static::$default_options, $opts);
// wrap the html in case it consists of adjacent nodes like foo
bar
$html = mb_convert_encoding("".$html."
", 'HTML-ENTITIES', 'UTF-8');
$root_node = null;
// Parse using HTML5Lib if it's available.
if (class_exists('HTML5Lib\\Parser')) {
try {
$doc = \HTML5Lib\Parser::parse($html);
$root_node = $doc->documentElement->lastChild->lastChild;
}
catch (\Exception $e) {
;
}
}
if ($root_node === null) {
// HTML5Lib not available so we'll have to use DOMDocument
// We'll only be able to parse HTML5 if it's valid XML
$doc = new DOMDocument('4.01', 'utf-8');
$doc->formatOutput = false;
$doc->preserveWhiteSpace = true;
// loadHTML will fail with HTML5 tags (article, nav, etc)
// so we need to suppress errors and if it fails to parse we
// retry with the XML parser instead
$prev_use_errors = libxml_use_internal_errors(true);
if ($doc->loadHTML($html)) {
$root_node = $doc->documentElement->lastChild->lastChild;
}
else if ($doc->loadXML($html)) {
$root_node = $doc->documentElement;
}
else {
libxml_use_internal_errors($prev_use_errors);
throw new \RuntimeException;
}
libxml_use_internal_errors($prev_use_errors);
}
list($text, $_, $opts) = static::truncateNode($doc, $root_node, $length, $opts);
$text = mb_substr(mb_substr($text, 0, -6), 5);
return $text;
}
protected static function truncateNode($doc, $node, $length, $opts)
{
if ($length === 0 && !static::ellipsable($node)) {
return array('', 1, $opts);
}
list($inner, $remaining, $opts) = static::innerTruncate($doc, $node, $length, $opts);
if (0 === mb_strlen($inner)) {
return array(in_array(mb_strtolower($node->nodeName), static::$self_closing_tags) ? $doc->saveXML($node) : "", $length - $remaining, $opts);
}
while($node->firstChild) {
$node->removeChild($node->firstChild);
}
$newNode = $doc->createDocumentFragment();
// handle the ampersand
$newNode->appendXml(static::xmlEscape($inner));
$node->appendChild($newNode);
return array($doc->saveXML($node), $length - $remaining, $opts);
}
protected static function innerTruncate($doc, $node, $length, $opts)
{
$inner = '';
$remaining = $length;
foreach($node->childNodes as $childNode) {
if ($childNode->nodeType === XML_ELEMENT_NODE) {
list($txt, $nb, $opts) = static::truncateNode($doc, $childNode, $remaining, $opts);
}
else if ($childNode->nodeType === XML_TEXT_NODE) {
list($txt, $nb, $opts) = static::truncateText($doc, $childNode, $remaining, $opts);
} else {
$txt = '';
$nb = 0;
}
// unhandle the ampersand
$txt = static::xmlUnescape($txt);
$remaining -= $nb;
$inner .= $txt;
if ($remaining < 0) {
if (static::ellipsable($node)) {
$inner = preg_replace('/(?:[\s\pP]+|(?:&(?:[a-z]+|#[0-9]+);?))*$/', '', $inner).$opts['ellipsis'];
$opts['ellipsis'] = '';
$opts['was_truncated'] = true;
}
break;
}
}
return array($inner, $remaining, $opts);
}
protected static function truncateText($doc, $node, $length, $opts)
{
$string = $node->textContent;
if ($opts['length_in_chars']) {
$count = mb_strlen($string);
if ($count <= $length && $length > 0) {
return array($string, $count, $opts);
}
if ($opts['word_safe']) {
if (false !== ($breakpoint = mb_strpos($string, $opts['break'], $length))) {
if ($breakpoint < mb_strlen($string) - 1) {
$string = mb_substr($string, 0, $breakpoint) . $opts['break'];
}
}
return array($string, $count, $opts);
}
return array(mb_substr($node->textContent, 0, $length), $count, $opts);
}
else {
preg_match_all('/\s*\S+/', $string, $words);
$words = $words[0];
$count = count($words);
if ($count <= $length && $length > 0) {
return array($xhtml, $count, $opts);
}
return array(implode('', array_slice($words, 0, $length)), $count, $opts);
}
}
protected static function ellipsable($node)
{
return ($node instanceof DOMDocument)
|| in_array(mb_strtolower($node->nodeName), static::$ellipsable_tags)
;
}
protected static function xmlEscape($string)
{
$string = str_replace('&', '&', $string);
$string = str_replace('