gnu-social/plugins/Oembed/lib/opengraphhelper.php

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<?php
if (!defined('GNUSOCIAL')) { exit(1); }
/**
* Utility class to get OpenGraph data from HTML DOMs etc.
*/
class OpenGraphHelper
{
const KEY_REGEX = '/^og\:(\w+(?:\:\w+)?)/';
protected static $property_map = [
'site_name' => 'provider_name',
'title' => 'title',
'description' => 'html',
'type' => 'type',
'url' => 'url',
'image' => 'thumbnail_url',
'image:height' => 'thumbnail_height',
'image:width' => 'thumbnail_width',
];
// This regex map has: /pattern(match)/ => matchindex | string
protected static $type_regex_map = [
'/^(video)/' => 1,
'/^image/' => 'photo',
];
static function ogFromHtml(DOMDocument $dom) {
$obj = new stdClass();
$nodes = $dom->getElementsByTagName('meta');
for ($i = 0; $i < $nodes->length; $i++) {
$node = $nodes->item($i);
if (!$node->hasAttributes()) {
continue;
}
$property = $node->attributes->getNamedItem('property');
$matches = array();
if ($property === null || !preg_match(self::KEY_REGEX, $property->value, $matches)) {
// not property="og:something"
continue;
}
if (!isset(self::$property_map[$matches[1]])) {
// unknown metadata property, nothing we would care about anyway
continue;
}
$prop = self::$property_map[$matches[1]];
$obj->{$prop} = $node->attributes->getNamedItem('content')->value;
// I don't care right now if they're empty
}
if (isset($obj->type)) {
// Loop through each known OpenGraph type where we have a match in oEmbed
foreach (self::$type_regex_map as $pattern=>$replacement) {
$matches = array();
if (preg_match($pattern, $obj->type, $matches)) {
$obj->type = is_int($replacement)
? $matches[$replacement]
: $replacement;
break;
}
}
// If it's not known to our type map, we just pass it through in hopes of it getting handled anyway
} elseif (isset($obj->url)) {
// If no type is set but we have a URL, let's set type=link
$obj->type = 'link';
}
return $obj;
}
}