Based on the rules in http://tools.ietf.org/html/draft-abarth-mime-sniff-06
This is used since we can't always trust Content-Type headers, and is based
upon the HTML5 parsing rules.
This class can be overloaded with {@see \SimplePie::set_content_type_sniffer_class()}
/**
* Get the Content-Type of the specified file
*
* @access public
* @return string Filtered content type
*/
function get_type()
{
$contentType = null;
$charset = null;
if (isset($this->file->headers['content-type'])) {
if (!is_array($this->file->headers['content-type'])) {
$this->file->headers['content-type'] = array($this->file->headers['content-type']);
}
foreach ($this->file->headers['content-type'] as $type) {
$parts = array_map('trim', explode(";", $type, 2));
if (isset($parts[1])) {
$type = $parts[0];
$charset = $parts[1];
}
if (preg_match('!(application|text)/((atom|rss|rdf)\\+)?xml!', $type, $ref)) {
$contentType = $ref[0];
}
}
$outHeader = array();
if (!is_null($contentType)) {
$outHeader[] = $contentType;
} else {
$outHeader[] = 'text/xml';
// Generic
}
if (!is_null($charset)) {
$outHeader[] = $charset;
}
$this->file->headers['content-type'] = implode("; ", $outHeader);
} else {
// The default SimplePie behavior seems to be to return
// text/plain if it can't find a Content-Type header.
// The default SimplePie behavior sucks. Particularly
// since SimplePie gets so draconian about Content-Type.
// And since the WP SimplePie seems to drop Content-Type
// from cached copies for some unfortunate reason.
$this->file->headers['content-type'] = 'text/xml';
// Generic
}
return parent::get_type();
}
public static function checkFavicon($favicon)
{
if ($favicon === null || $favicon == false) {
return false;
}
$file = new \SimplePie_File($favicon);
// size in bytes
$filesize = strlen($file->body);
if ($file->success && $filesize > 0 && $filesize < 50000) {
//bigger files are not considered favicons
$sniffer = new \SimplePie_Content_Type_Sniffer($file);
if (substr($sniffer->get_type(), 0, 6) === 'image/') {
$imgsize = getimagesize($favicon);
if ($imgsize['0'] <= 32 && $imgsize['1'] <= 32) {
//bigger images are not considered favicons
return true;
}
}
}
return false;
}
/**
* Test if the file is an image
* @param string $url the url to the file
* @return bool true if image
*/
protected function isImage($url)
{
// check for empty urls
if (!$url) {
return false;
}
$file = $this->getFile($url);
$sniffer = new \SimplePie_Content_Type_Sniffer($file);
return $sniffer->image() !== false;
}
/**
* Test if the file is an image
* @param string $url the url to the file
* @return bool true if image
*/
protected function isImage($url)
{
// check for empty urls
if (!$url) {
return false;
}
$file = $this->getFile($url);
$status_range = (string) substr($file->status_code, 0, 1);
//echo $status_range;
if ($status_range == 2 || $status_range == 3 || !empty($status_range)) {
// 200's are a good response and 300's are redirects
$sniffer = new \SimplePie_Content_Type_Sniffer($file);
return $sniffer->image() !== false;
}
}
