Send email for pending post

Question

I've found this code that worked perfectly for notifying admin when a post is updated, but it's annoying the admin because she's getting emails for all updates and she only wants notifications for posts that are pending. I cannot figure out how to do this.

Here's my code so far:

add_action( 'save_post', 'my_project_updated_send_email' ); 
function my_project_updated_send_email( $post_id ) { 
    //verify post is not a revision 
    if ( !wp_is_post_revision( $post_id ) ) { 
        $post_title = get_the_title( $post_id ); 
        $post_url = get_permalink( $post_id ); 
        $subject = 'A post has been updated'; 
        $message = "A post has been updated on your website:\n\n";
        $message .= "<a href='". $post_url. "'>" .$post_title. "</a>\n\n"; 
        //send email to admin 
        wp_mail( 'amdin@test.co.uk', $subject, $message ); 
    } 
} 

I've tried changing add_action('save_post'

to add_action('on_publish_pending_post'

But that didn't work. I tried just 'pending', but that didn't work. I'm a bit stuck.

Answer 1

I did a bit more research and this is what is working for me now.

The admin will only get an update if a pending post is added or updated.

add_action( 'transition_post_status', 'pending_post_status', 10, 3 );

function pending_post_status( $new_status, $old_status, $post ) {

  if ( $new_status === "pending" ) {

    $post_title = get_the_title( $post_id ); 
     $post_url = get_permalink( $post_id ); 
     $subject = 'A post has been updated'; 
     $message = "A post has been updated on your website:\n\n";
     $message .= "<a href='". $post_url. "'>" .$post_title. "</a>\n\n"; 
     //send email to admin 

     wp_mail( 'admin@test.co.uk' , $subject, $message ); 
  }

}