'wp' action hook not firing in admin and login?

Question

I need to register an action via

add_action('wp', function(){...});

The action works in frontend, but in backend and login page it doesn't work. It seems as if 'wp' hook doesn't exist for administration and login page.

Am I missing something or is there any alternative?

Use case description: I have a special tag (custom taxonomy term) for one of the pages. If user is not logged in and tries to access the backend s/he should be redirected to the page that has the tag. To find out which page has that tag I use WP_Query with tax_query. Therefore, I need a hook that is triggered after custom taxonomies (and custom post types) are registered, but also that is triggered before headers are set.

Any idea?

Answer 1

I just observed the same problem, and fixed it by using the "admin_init" Action instead. I only want it to fire in Admin, but if you want it to fire for Public as well as Admin, simply use two add_action's, one for wp and admin_init, though I would make it conditional:

if ( is_admin() ) {
   add_action( 'admin_init',...
} else {
   add_action( 'wp',...
}