getting the main image from another url? - php

Question

I have a function which returns all img links of any web page but i want to take the image that represent the news article best . I know that it is a little hard question but every news articles have some main image on top of the article . I need to pick it among all of other images . Facebook and reddit like sites can do that . Do you have any kind of idea ? When members of my website shared a link , there should be a picture for it . I can take all url of images in a web page now i need to find main image . :)
function get_links($url) {
$xml = new DOMDocument();
libxml_use_internal_errors(true);
$html = file_get_contents($url);
if(!$xml->loadHTML($html)) {
$errors="";
foreach (libxml_get_errors() as $error) {
$errors.=$error->message."<br/>";
}
libxml_clear_errors();
print "libxml errors:<br>$errors";
return;
}
// Empty array to hold all links to return
$links = array();
//Loop through each <img> tag in the dom and add it to the link array
foreach ($xml->getElementsByTagName('img') as $link) {
$url = $link->getAttribute('src');
if (!empty($url)) {
$links[] = $link->getAttribute('src');
}
}
//Return the links
return $links;
}

Answer 1

You can improve your existing function, but if you want to preference the existence of the Open Graph data, add this before your getElementsByTagName('img') logic...
$xpath = new DOMXPath( $xml );
if( $xpathNodeList = $xpath->query('//meta[#property="og:image" and #content]') )
{
return array( $xpathNodeList->item(0)->getAttribute('content') );
}
or add it to your array...
// Empty array to hold all links to return
$links = array();
$xpath = new DOMXPath( $xml );
if( $xpathNodeList = $xpath->query('//meta[#property="og:image" and #content]') )
{
$links[] = $xpathNodeList->item(0)->getAttribute('content');
}