Is there any filter available to set the naming convention of those auto generated thumbnails?
Something like this:
- thumbnail_150x150.jpg -> thumbnail-s.jpg
- thumbnail_300x300.jpg -> thumbnail-m.jpg
- thumbnail_600x600.jpg -> thumbnail-l.jpg
2 s
Seems that the answer is no…
I’ve followed the core functions and found a dead-end. And found this post ( How can I make add_image_size() crop from the top? ) where Rarst says:
Intermediate image generation is extremely rigid. Image_resize() keeps it close to code and completely lacks hooks.
But, following the lead of the other answer (from bradt) and the code he published ( Image Crop Position in WordPress ), I think I got it 🙂
In the function bt_generate_attachment_metadata
, I’ve just modified the call to bt_image_make_intermediate_size
including the last parameter $size
$resized = bt_image_make_intermediate_size( $file, $size_data['width'], $size_data['height'], $size_data['crop'], $size );
And modified the beggining of the function bt_image_make_intermediate_size
as follows:
- added the
$size
parameter to the function - instead of the default
null
value to$suffix
, aswitch
to our new suffixes
function bt_image_make_intermediate_size( $file, $width, $height, $crop = false, $size ) {
if ( $width || $height ) {
switch($size) {
case 'thumbnail':
$suffix = 't';
break;
case 'medium':
$suffix = 'm';
break;
case 'large':
$suffix = 'l';
break;
default:
$suffix = null;
break;
}
$resized_file = bt_image_resize( $file, $width, $height, $crop, $suffix, null, 90 );
 Here , a copy of the full code with my mods, just for reference.
And the diff from the original.
[2021]
I reviewed the code to fix the following warnings, (h/t @meek2100): two WP functions were deprecated and there’s a PHP 8 notice about named parameters.
Gist with the changes annotated on code.