BuddyPress.org

First question is
1) Should this be done by building a plugin or using bp-custom.php?

My main concern is that im trying to overwrite a function in bp-core.php using a plugin file.

The function is:

`function bp_core_get_username( $user_id, $user_nicename = false, $user_login = false )`

For some reason the arguments passed in this function are not being picked up in the custom function which I called:

`function bp_core_get_username_custom( $user_id, $user_nicename = false, $user_login = false )`

I used the following add action:

`add_action( ‘bp_core_get_username’, ‘bp_core_get_username_custom’, 1,3 );`

Am I doing something obviously wrong or does anyone think there is a deeper problem with my code?