How to get the nid for a newly created node?

Question

If I've created a node in an install hook, how can I immediately get a reference to the nid property? It doesn't appear to be set on the entity during save.

use Drupal\node\Entity\Node;

function my_frontpage_install() {
    $node = Node::create(array(
        'type' => 'page',
        'title' => t('Welcome'),
        'body' => array(array(
            'value' => 'Hi there'
        )),
    ));

    $node->save();

    $siteConfig = \Drupal::service('config.factory')->getEditable('system.site');
    $pageConfig = $siteConfig->get('page');
    $pageConfig['front'] = 'node/' . $node->getId(); // this returns null
    $siteConfig->set('page', $pageConfig);
    $siteConfig->save();
}

I've tried variations on the theme of getId, getNid(), get('nid'), getOriginalId(), but if I dump out the node object afer saving, the nid property is clearly not set.

Answer 1

The nice thing about Drupal 8, is that it's object oriented, with interfaces, abstract classes etc.

This means that all entities share a lot of methods. To get the id of a node, use the id method

$nid = $node->id();

This also works for users, taxonomy terms and any other entities you create yourself or get from contrib modules modules.

For Drupal 8 development, using an IDE becomes really powerfull as it can help you with what available methods, various instances of classes has.