Prevent spaces in BuddyPress usernames

no-spaces-buddypress-usernames.php

<?php

add_action( 'bp_loaded','bpdev_remove_bp_pre_user_login_action') ;
/**
 * BuddyPress replaces the space with '-' which is not known to the user
 * We remove the attached function to stop BP from circumventing the space in username
 * 
 */
function bpdev_remove_bp_pre_user_login_action(){
  
  remove_action( 'pre_user_login', 'bp_core_strip_username_spaces' );

}
 
add_filter( 'validate_username','bpdev_restrict_space_in_username',10,2) ;
/**
 * add a filter to invalidate a username with spaces
 * 
 */
function bpdev_restrict_space_in_username( $valid,$user_name ){
  
  //check if there is an space
  if ( preg_match('/\s/',$user_name ) )
 
  //if yes, then we say it is an error
  return false;
  
  //otherwise return the actual validity
  return $valid;

}