Wordpress - Rename UPLOADS folder with custom WP_CONTENT_DIR

After digging around, I ended up with using upload_dir filter.

Here is what I tried in functions.php to change uploads to media. Hope it can help someone too :)

 add_filter('upload_dir', function($uploads)
 {
     $custom = [];

     foreach ($uploads as $key => $value) {
         if ( false !== strpos($value, '/app/uploads') ) {
             $custom[$key] = str_replace('/app/uploads', '/app/media', $value);
         } else {
             $custom[$key] = $value;
         }
     }

     return $custom;
 });

Many thanks to @gmazzap for the guidelines and the suggestion about upload_dir filter!

If you look at the source of _wp_upload_dir, you'll see:

if (defined('UPLOADS') && ! (is_multisite() && get_site_option('ms_files_rewriting'))) {
    $dir = ABSPATH.UPLOADS;
    $url = trailingslashit($siteurl).UPLOADS;
}

So UPLOADS can only be used to define a foder relative to ABSPATH, which I guess is /WordPress folder in your setup.

In the same function, you can see that if get_option('upload_path') and get_option('upload_url_path') are empty, the path and the URL of uploads folder are set to, respectively, WP_CONTENT_DIR.'/uploads' and WP_CONTENT_URL.'/uploads' which should be perfectly fine for you, as long as you define WP_CONTENT_DIR and WP_CONTENT_URL like in OP.

If you don't define UPLOADSat all and the uploads folder is still not resolved to /app/uploads, very likely your database contains some value for 'upload_path' and 'upload_url_path' options.

You have 2 possibilities:

• delete those options
• use "pre_option_{$option}" filters to force get_option() to return something empty for those options (but not false or the filters will be ignored).

For the second possibility the code could be something like this:

add_filter('pre_option_upload_path', '__return_empty_string');
add_filter('pre_option_upload_url_path', '__return_empty_string');

With the above code in place, and without any UPLOADS constant defined, as long as you define WP_CONTENT_DIR and WP_CONTENT_URL, the uploads folder should be resolved correctly.

If that not happen, there must be something that acts on some filter, for instance upload_dir.