Hook priority in admin with custom plugin

Question

As mentioned here admin_init is the first hook triggered when access wordpress dashboard.

But when I test it I found tgmpa_register triggers first

add_action( 'admin_init', 'sr_admin_init' );
add_action( 'tgmpa_register', 'sr_register_required_plugins' );

function sr_admin_init(){
   // I NEED THIS TO TRIGGER FIRST
    wp_die("sr_admin_init");
}

function sr_register_required_plugins(){
   // this triggers first
    wp_die("sr_register_required_plugins");
}

Action hooks triggers:

1. tgmpa_register
2. admin_init: defines some variable like $GLOBALS['admin_page_hooks']

I have a complicated case, but in general I need to use variable $GLOBALS['admin_page_hooks'] in sr_register_required_plugins. But it is not working because tgmpa_register triggers first.

What should I do?

Answer 1

The codex entry you site is simply wrong! There are a lot of hooks fired before admin_init during admin requests, not least of which is init, which a lot of plugins use to do their initialization.

In particular, the TGM Plugin Activation plugin hooks into init (with the default priority = 10) with a function that calls do_action ('tgmpa_register').

Hence, you'll need to do something like:

// make sure we register this hook func with lower priority value than 
// TGM Plugin Activation does
add_action ('init', 'sr_admin_init', 9) ;

function
sr_admin_init ()
{
    if (!is_admin ()) {
        return ;
        }

    // I NEED THIS TO TRIGGER FIRST
    wp_die("sr_admin_init");
}

Edit

To be more charitable to the author of the codex entry you site: admin_init is the 1st "strictly admin"-related hook fired for admin requests. It's just not the 1st hook fired.