Filter Image insert for WordPress

wp.filter.php

function xf_insert_image( $html, $id, $caption, $title, $align, $url  )
{
  
  $html5 = "<figure id='post-$id media-$id' class='align-$align'>";
  $html5 .= "<img src='$url' alt='$title' />";
  $html5 .= "<figcaption>$caption</figcaption>";
  $html5 .= "</figure>";
  
  return $html5;
}
add_filter( 'image_send_to_editor', 'xf_insert_image', 10, 9 );

Only change I'd make is not outputting figcaption if no caption:

function html5_insert_image($html, $id, $caption, $title, $align, $url) {
  $html5 = "<figure id='post-$id media-$id' class='align-$align'>";
  $html5 .= "<img src='$url' alt='$title' />";
  if ($caption) {
    $html5 .= "<figcaption>$caption</figcaption>";
  }
  $html5 .= "</figure>";
  return $html5;
}
add_filter( 'image_send_to_editor', 'html5_insert_image', 10, 9 );

Thanks!

True that!

I just wish I could figure out how to modify the output when the user edits the image align and class in the visual editor.

Hattip, @rezen. Thanks.