从外部页面链接获取“标题”和“描述”

Question

I am trying to get title, description from external page link source. This is not working when I am trying to get Facebook page source and is returning source code of some another page. It is working on other websites like google etc. Here is my code in PHP :

$ch = curl_init();
   curl_setopt($ch, CURLOPT_HEADER, 0);
   curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
   curl_setopt($ch, CURLOPT_URL, $url);
   curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
   $data = curl_exec($ch);
   curl_close($ch);
   return $data;
}

public function previewLink(){
   $url = "https://www.facebook.com/NASA/";
   $html = $this->file_get_contents_curl($url);
   $title = "";
   $description ="";
   $image = "";

   //parsing begins here:
   $doc = new \DOMDocument();
   @$doc->loadHTML($html);
   $nodes = $doc->getElementsByTagName('title');
   $title = $nodes->item(0)->nodeValue();
  }

I am not getting what is the problem I am facing. Can someone suggest something ? Thanks in advance.

Answer 1

Facebook requires UserAgent string in http request. You can add that by using this

curl_setopt($ch, CURLOPT_HTTPHEADER, array('User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_4) AppleWebKit/600.7.12 (KHTML, like Gecko) Version/8.0.7 Safari/600.7.12'));

FYI: facebook uses to display captcha page when anyone goes to a page without login.