Getting file path of an attachment in wordpress

Question

I'm trying to get the file path of an attachment so that its uploaded to vimeo directly from a custom_post_type in Wordpress but $attachment_id is returning a null . How can i get the $attachment_id ?

 global $attachment_id;
  $filepath = get_attached_file( $attachment_id ); 
  $url = 'https://api.vimeo.com/me/videos';
  $args = array(
      'type'=>'pull',
      'link'=>'the_link',
    );
  $response_vimeo = wp_safe_remote_post ( $url, $args);  

Answer 1

There are many possibilities depending on the situation you are trying to execute this code in. One possibility is

$post = get_post();
$attachment_id = $post->ID;

Or maybe the id is coming in from a $_POST or $_GET variable. Try adding print_r($_POST); print_r($_GET); and see what you get if you're submitting a form or creating a post.