public function deleteBookAction($parameters)
{
$isbn = $parameters['isbn'];
$bookRepository = new BookRepository();
$bookRepository->deleteBook($isbn);
$this->initRouter("/books/show-all.php");
$this->router->initControllerAction();
}
public function showAction($parameters)
{
$area = array_key_exists('area', $parameters) ? $parameters['area'] : 'All';
$bookRepository = new BookRepository();
$booksCollection = $bookRepository->getBooksByKnowledgeArea($area);
$data['books'] = $bookRepository->getArrayFromCollection($booksCollection);
echo json_encode($data);
}