Extract value from background-image style attribute with xpath

Question

Ii have the follow structure:

I need that output:

Answer 1

1) You lost quotes wrapping xpath - it's string.

2) with dom xpath, query returns set of nodes while to receive string result it's better to use evaluate

$img = $xpath->evaluate('substring-before(substring-after(//div[@class=\'xGh\']/@style, "background-image: url(\'"), "\')")');    

echo $img; // it contains name_file.jpg

demo