PHP nodeValue being classified as non-object

Question

Recently I have been experimenting with making my own rudimentary search engine. Things have been going smoothly as I have the URL's and URL hashes logged into my phpMyAdmin database, no title or descriptions were logged but the program did work with sites such as YouTube, Google, and a local music venue. However recently I have encountered an error that I can't seem to fix and is stopping new websites from being added to my table and I have been receiving this error message:

Notice: Trying to get property 'nodeValue' of non-object in C:\xampp\htdocs\se\index.php on line 22

I have tried making slight adjustments, such as ensuring that the item is an object by using a code

if (is_object($title ->item(0))) {
    $title = $title->item(0)->nodeValue;
}
// Does not work, PHP Recoverable fatal error:  Object of class DOMNodeList could not be converted 
// to string...

but this only lead to an issue that would not allow the program to move forward.

here is the preceding code up until the error

$already_crawled = array();
$crawling = array();

function get_details($url) {

    $options = array('http' => array('method' => "GET", 'headers' => "User-Agent: howBot/0.1\n"));
    $context = stream_context_create($options);
    $doc = new DOMDocument();

    @$doc->loadHTML(@file_get_contents($url, false, $context));

    $title = $doc->getElementsByTagName("title");
    $title = $title->item(0)->nodeValue; // error occurs here

I am using php7 and I'm still relatively new to it so any other advice would help. Thanks