Get from the dashboard the ID of the current post being edited

Question

I need to take the ID of the post that is loaded in the dashboard for editing. get_the_ID or get_queried_object() seems to not work, even if this functions are supposed to be used also outside the loop.

I need the post ID to prevent a role from editing this post in the dashboard, so I can do something like: if the post that the user attempt to load has the ID == 9, redirect the user to the dashboard home or die.

So, how can I get the ID of the current post that the user attempt to load?

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Edit: The following is one of the piece of code I tried. If the role is matched, the user is in the dashboard and the post has the category ID == 20 (assuming that has_category take the current post if an ID is not specified), then die.

    add_action('admin_init', 'bck_restrict_post');
    function bck_restrict_post() {
        if (current_user_can('myrole') && is_admin() && has_category(20) ) {
        wp_die();
      }    
   }

It's very simple, but has_category doesn't work. It doesn't take the current post ID and nothing change. I've also tried using in_category(); same result.

Answer 1

Here's a simple example that redirects to the edit posts screen. Since what you're asking for is how to get the post, I'm not bothering with messages or particular redirect pages or other variables - though note that wp_die() will just kill the page. In my tests, it just gets you a blank one.

Anyway, I think the two things you need are the load-(page) hook and the ID from the $_GET variable when editing posts:

add_action( 'load-post.php', 'redirect_post_x' ) ;

function redirect_post_x() {

    //if post ID = 99999: ID not cast as int here
    if ( $_GET[ 'post' ] === '99999' ) {

        wp_redirect( admin_url( 'edit.php' ) );
        exit;

    }

}