The Simple and Correct Way to Add User Meta

Question

I want to give points to users to their activities like writing posts, writing comments, etc.

I thought to use user meta to store points.

I know that I can use add_user_meta...

But the problem is, there are many ways to register a user for my site like normal reg form, buddypress reg form, Admins can add via admin panel and many more.

So it is hard to add add_user_meta to every where.

Is they any way to add a user meta for all current users and future uses with a default value?

Answer 1

Trying to detect when a UI was triggered, is indeed the wrong general approach (unless you want to tie to the UI). A proper one will be to hook on the user_register action.

add_action( 'user_register', 'wpse223196_registration_save', 10, 1 );

function wpse223196_registration_save( $user_id ) {

   add_user_meta($user_id, 'score', 5);

}