Add affiliate disclosure WP Snippet

affiliate-disclosure.php

/* Add affiliate disclosure before the content */

function my_content_filter($content){
  //only add text before WordPress posts
  if(is_single() && is_main_query()){
    $before = '<div class="disclosure">This post may contain affiliate links, which means we may earn a commission if you make a purchase. As an Amazon Associate we earn from qualifying purchases. Thank you for your support!</div>';
    $after = '<div class="after-entry"></div>'; 

    //modify the incoming content 
    $content = $before . $content . $after; 
  } 
  return $content; 
}
add_filter( 'the_content', 'my_content_filter' );