BuddyPress

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?

there is no action to trigger on (though that wouldn’t allow you to overwrite a function – i don’t believe any “pluggable” functions exists in bp. action is just a hook point)

there is a filter on the return of that function though bp_core_get_username but passes the determined username

Yeah, there are not any ‘plugable’ functions in BP.