<?php
function add_custom_avatar($user_id, $attachment_id){
if(!empty(get_user_meta($user_id, 'user_avatar', true))){
return update_user_meta($user_id, 'user_avatar', wp_get_attachment_url($attachment_id));
}
return add_user_meta($user_id, 'user_avatar', wp_get_attachment_url($attachment_id), true);
}
function get_custom_avatar_url($url, $id_or_email, $args){
if(!$id_or_email) return $url;
if(is_int($id_or_email)){
$avatar = get_user_meta($id_or_email, 'user_avatar', true);
if(!empty($avatar)) return $avatar;
}else{
}
}
add_filter('get_avatar_url', 'get_custom_avatar_url');