/**
* This function cuts out requested tag information from html head
* @access public
* @param $text html text
* @param $tags a string or an array of requested tags
* @author Cindy Qi Li
*/
public static function getHtmlHeadByTag($text, $tags)
{
$head = ContentUtility::getHtmlHead($text);
$rtn_text = "";
if (!is_array($tags) && strlen(trim($tags)) > 0) {
$tags = array(trim($tags));
}
foreach ($tags as $tag) {
$tag = strtolower($tag);
/* strip everything before <{tag}> */
$start_pos = stripos($head, '<' . $tag);
$temp_head = $head;
while ($start_pos !== false) {
$temp_text = substr($temp_head, $start_pos);
/* strip everything after </{tag}> or />*/
$end_pos = stripos($temp_text, '</' . $tag . '>');
if ($end_pos !== false) {
$end_pos += strlen('</' . $tag . '>');
// add an empty line after each tag information
$rtn_text .= trim(substr($temp_text, 0, $end_pos)) . '
';
} else {
$end_pos = stripos($temp_text, '/>');
if ($end_pos === false && stripos($temp_text, $tag . '>') === false) {
//if /> is not found, then this is not a valid XHTML
//text iff it's not tag>
$end_pos = stripos($temp_text, '>');
$end_pos += strlen('>');
} else {
$end_pos += strlen('/>');
}
// add an empty line after each tag information
$rtn_text .= trim(substr($temp_text, 0, $end_pos)) . '
';
}
// initialize vars for next round of matching
$temp_head = substr($temp_text, $end_pos);
$start_pos = stripos($temp_head, '<' . $tag);
}
}
return $rtn_text;
}
