Automatically Add Caption Shortcode to Image with Caption Field Filled In

Question

I am hoping to be able to have the [caption] shortcode automatically get inserted into the post content area when you add in an image that has the caption field filled in. I believe this is supposed to be the default functionality in WordPress. Is there anything I need to declare in the functions.php file to make this work in my custom theme though?

Thanks!

Answer 1

Did a bit more digging and it appears to have been a conflict in my theme:

add_filter( 'post_thumbnail_html', 'remove_width_attribute', 10 );
add_filter( 'image_send_to_editor', 'remove_width_attribute', 10 );
function remove_width_attribute( $html ) {
  $html = preg_replace( '/(width|height)="\d*"\s/', "", $html );
  return $html;
}