Profile: aaronM-9

function be_get_parent_id($atts){
   
    //Get current post object and ID
    global $post;
    $post_id_current = $post->ID;
   
    $a = shortcode_atts( array(
        'postid' => $post_id_current,
        'parent' => '',
    ), $atts );
 
    //get post type
    $post_id_current = $a['postid'];
    $post_type_current = get_post_type($post_id_current);
  
    //The Post relationship slug to check - NOTE THE NEW SYNTAX WITH - HERE
    $relationship_to_query = $a['parent']."-".$post_type_current;
   
    //Set the role the other post type has:
    $role = "parent";
   
//Get related posts with new API, if none, it'll return 0, if any, the ID (hence not 0)
    // try legacy method, fallback to new method
    $related_post = toolset_get_related_post( $post_id_current, array($a['parent'], $post_type_current), $role);
    if (! $related_post ){
        $related_post = toolset_get_related_post( $post_id_current, $relationship_to_query, $role);
    }
    return $related_post;
}
add_shortcode( 'be-get-parent-id', 'be_get_parent_id' );