Insertar imágenes con Figure / Figcaption | Programar Plus

Para un complemento simple o un archivo functions.php:

function html5_insert_image($html, $id, $caption, $title, $align, $url) {
  $html5 = "<figure id='post-$id media-$id' class="align-$align">";
  $html5 .= "<img src="https://css-tricks.com/snippets/wordpress/insert-images-with-figurefigcaption/$url" alt="$title" />";
  if ($caption) {
    $html5 .= "<figcaption>$caption</figcaption>";
  }
  $html5 .= "</figure>";
  return $html5;
}
add_filter( 'image_send_to_editor', 'html5_insert_image', 10, 9 );