How to get Open Graph Protocol of a webpage by php? - php

Question

PHP has a simple command to get meta tags of a webpage (get_meta_tags), but this only works for meta tags with name attributes. However, Open Graph Protocol is becoming more and more popular these days. What is the easiest way to get the values of opg from a webpage. For example:
<meta property="og:url" content="">
<meta property="og:title" content="">
<meta property="og:description" content="">
<meta property="og:type" content="">
The basic way I see is to get the page via cURL and parse it with regex. Any idea?

Answer 1

Really simple and well done:
Using https://github.com/scottmac/opengraph
$graph = OpenGraph::fetch('http://www.avessotv.com.br/bastidores-pantene-institute-experience-pg.html');
print_r($graph);
Will return
OpenGraph Object
(
[_values:OpenGraph:private] => Array
(
[type] => article
[video] => http://www.avessotv.com.br/player/flowplayer/flowplayer-3.2.7.swf?config=%7B%27clip%27%3A%7B%27url%27%3A%27http%3A%2F%2Fwww.avessotv.com.br%2Fmedia%2Fprogramas%2Fpantene.flv%27%7D%7D
[image] => /wp-content/thumbnails/9025.jpg
[site_name] => Programa Avesso - Bastidores
[title] => Bastidores “Pantene Institute Experience†P&G
[url] => http://www.avessotv.com.br/bastidores-pantene-institute-experience-pg.html
[description] => Confira os bastidores do Pantene Institute Experience, da Procter & Gamble. www.pantene.com.br Mais imagens:
)
[_position:OpenGraph:private] => 0
)

Answer 2

When parsing data from HTML, you really shouldn't use regex. Take a look at the DOMXPath Query function.
Now, the actual code could be :
[EDIT] A better query for XPath was given by Stefan Gehrig, so the code can be shortened to :
libxml_use_internal_errors(true); // Yeah if you are so worried about using # with warnings
$doc = new DomDocument();
$doc->loadHTML($html);
$xpath = new DOMXPath($doc);
$query = '//*/meta[starts-with(#property, \'og:\')]';
$metas = $xpath->query($query);
$rmetas = array();
foreach ($metas as $meta) {
$property = $meta->getAttribute('property');
$content = $meta->getAttribute('content');
$rmetas[$property] = $content;
}
var_dump($rmetas);
Instead of :
$doc = new DomDocument();
#$doc->loadHTML($html);
$xpath = new DOMXPath($doc);
$query = '//*/meta';
$metas = $xpath->query($query);
$rmetas = array();
foreach ($metas as $meta) {
$property = $meta->getAttribute('property');
$content = $meta->getAttribute('content');
if(!empty($property) && preg_match('#^og:#', $property)) {
$rmetas[$property] = $content;
}
}
var_dump($rmetas);

Answer 3

How about:
preg_match_all('~<\s*meta\s+property="(og:[^"]+)"\s+content="([^"]*)~i', $str, $matches);
So, yes, grab the page with any way you can and parse with regex

Answer 4

This function does the job without dependency and DOM parsing:
function getOgTags($html)
{
$pattern='/<\s*meta\s+property="og:([^"]+)"\s+content="([^"]*)/i';
if(preg_match_all($pattern, $html, $out))
return array_combine($out[1], $out[2]);
return array();
}
test code:
$x=' <title>php - Using domDocument, and parsing info, I would like to get the 'href' contents of an 'a' tag - Stack Overflow</title>
<link rel="shortcut icon" href="https://cdn.sstatic.net/Sites/stackoverflow/img/favicon.ico?v=4f32ecc8f43d">
<link rel="apple-touch-icon image_src" href="https://cdn.sstatic.net/Sites/stackoverflow/img/apple-touch-icon.png?v=c78bd457575a">
<link rel="search" type="application/opensearchdescription+xml" title="Stack Overflow" href="/opensearch.xml">
<meta name="referrer" content="origin" />
<meta property="og:type" content="website"/>
<meta property="og:url" content="https://stackoverflow.com/questions/5278418/using-domdocument-and-parsing-info-i-would-like-to-get-the-href-contents-of"/>
<meta property="og:image" itemprop="image primaryImageOfPage" content="https://cdn.sstatic.net/Sites/stackoverflow/img/apple-touch-icon#2.png?v=73d79a89bded" />
<meta name="twitter:card" content="summary"/>
<meta name="twitter:domain" content="stackoverflow.com"/>
<meta name="twitter:title" property="og:title" itemprop="title name" content="Using domDocument, and parsing info, I would like to get the 'href' contents of an 'a' tag" />
<meta name="twitter:description" property="og:description" itemprop="description" content="Possible Duplicate:
Regular expression for grabbing the href attribute of an A element
This displays the what is between the a tag, but I would like a way to get the href contents as well.
Is..." />';
echo '<pre>';
var_dump(getOgTags($x));
and you get:
array(3) {
["type"]=>
string(7) "website"
["url"]=>
string(119) "https://stackoverflow.com/questions/5278418/using-domdocument-and-parsing-info-i-would-like-to-get-the-href-contents-of"
["image"]=>
string(85) "https://cdn.sstatic.net/Sites/stackoverflow/img/apple-touch-icon#2.png?v=73d79a89bded"
}

Answer 5

As per this method you will get key pair array of fabcebook open graph tags.
$url="http://fbcpictures.in";
$site_html= file_get_contents($url);
$matches=null;
preg_match_all('~<\s*meta\s+property="(og:[^"]+)"\s+content="([^"]*)~i', $site_html,$matches);
$ogtags=array();
for($i=0;$i<count($matches[1]);$i++)
{
$ogtags[$matches[1][$i]]=$matches[2][$i];
}

Answer 6

Here is what i am using to extract Og tags.
function get_og_tags($get_url = "", $ret = 0)
{
if ($get_url != "") {
$title = "";
$description = "";
$keywords = "";
$og_title = "";
$og_image = "";
$og_url = "";
$og_description = "";
$full_link = "";
$image_urls = array();
$og_video_name = "";
$youtube_video_url="";
$get_url = $get_url;
$ret_data = file_get_contents_curl($get_url);
//$html = file_get_contents($get_url);
$html = $ret_data['curlData'];
$full_link = $ret_data['full_link'];
$full_link = addhttp($full_link);
//parsing begins here:
$doc = new DOMDocument();
#$doc->loadHTML($html);
$nodes = $doc->getElementsByTagName('title');
if ($nodes->length == 0) {
$title = $get_url;
} else {
$title = $nodes->item(0)->nodeValue;
}
//get and display what you need:
$metas = $doc->getElementsByTagName('meta');
for ($i = 0; $i < $metas->length; $i++) {
$meta = $metas->item($i);
if ($meta->getAttribute('name') == 'description')
$description = $meta->getAttribute('content');
if ($meta->getAttribute('name') == 'keywords')
$keywords = $meta->getAttribute('content');
}
$og = $doc->getElementsByTagName('og');
for ($i = 0; $i < $metas->length; $i++) {
$meta = $metas->item($i);
if ($meta->getAttribute('property') == 'og:title')
$og_title = $meta->getAttribute('content');
if ($meta->getAttribute('property') == 'og:url')
$og_url = $meta->getAttribute('content');
if ($meta->getAttribute('property') == 'og:image')
$og_image = $meta->getAttribute('content');
if ($meta->getAttribute('property') == 'og:description')
$og_description = $meta->getAttribute('content');
// for sociotube video share
if ($meta->getAttribute('property') == 'og:video_name')
$og_video_name = $meta->getAttribute('content');
// for sociotube youtube video share
if ($meta->getAttribute('property') == 'og:youtube_video_url')
$youtube_video_url = $meta->getAttribute('content');
}
//if no image found grab images from body
if ($og_image != "") {
$image_urls[] = $og_image;
} else {
$xpath = new DOMXPath($doc);
$nodelist = $xpath->query("//img"); // find your image
$imgCount = 0;
for ($i = 0; $i < $nodelist->length; $i++) {
$node = $nodelist->item($i); // gets the 1st image
if (isset($node->attributes->getNamedItem('src')->nodeValue)) {
$src = $node->attributes->getNamedItem('src')->nodeValue;
}
if (isset($node->attributes->getNamedItem('src')->value)) {
$src = $node->attributes->getNamedItem('src')->value;
}
if (isset($src)) {
if (!preg_match('/blank.(.*)/i', $src) && filter_var($src, FILTER_VALIDATE_URL)) {
$image_urls[] = $src;
if ($imgCount == 10) break;
$imgCount++;
}
}
}
}
$page_title = ($og_title == "") ? $title : $og_title;
if(!empty($og_video_name)){
// for sociotube video share
$page_body = $og_video_name;
}else{
// for post share
$page_body = ($og_description == "") ? $description : $og_description;
}
$output = array('title' => $page_title, 'images' => $image_urls, 'content' => $page_body, 'link' => $full_link,'video_name'=>$og_video_name,'youtube_video_url'=>$youtube_video_url);
if ($ret == 1) {
return $output; //output JSON data
}
echo json_encode($output); //output JSON data
die;
} else {
$data = array('error' => "Url not found");
if ($ret == 1) {
return $data; //output JSON data
}
echo json_encode($data);
die;
}
}
usage of the function
$url = "https://www.alectronics.com";
$tagsArray = get_og_tags($url);
print_r($tagsArray);

Answer 7

The more XMLish way would be to use XPath:
$xml = simplexml_load_file('http://ogp.me/');
$xml->registerXPathNamespace('h', 'http://www.w3.org/1999/xhtml');
$result = array();
foreach ($xml->xpath('//h:meta[starts-with(#property, \'og:\')]') as $meta) {
$result[(string)$meta['property']] = (string)$meta['content'];
}
print_r($result);
Unfortunately the namespace registration is needed if the HTML document uses a namespace declaration in the <html>-tag.

Answer 8

With native PHP function get_meta_tags().
https://php.net/get_meta_tags