Add hook to include/suppress a book?

I wanted to suppress which books are listed in the block, using some complex rules best done in a module. Normal node access control was not enough for my use case, without getting very messy.

Added hook_show_book to ABB. It sends the id of the book to hook implementations. ABB shows a book if any module implementing the hook returns true for a given book. That makes it a white list, not a black list.

Here's the code, starting at 479. Sorry it's not in the right version control format. I don't know how to do that yet (but am learning!).

while ($book = db_fetch_object($result)) {
  if (!in_array($book->bid, $books)) {
    $allowed = module_invoke_all('show_book', $book->bid);
    if ( in_array(TRUE, $allowed) ) {
      $books[] = $book->bid;
    }
  }
}

Here's how a (silly) module might implement the hook:

function module_show_book($bid) {
  return $bid < 10;
}

This might be useful for others, or maybe not. Good chance there's a better way to implement it (I'm no expert). E.g., should the hook name be something like hook_abb_show_book?

Kieran
http://coredogs.com