Methods to derive node object

node-from.php

<?php
/**
 * Once we have access to a node object we can e.g. `dump($node)` to
 * discover properties, like `$node->get("field_example")->getValue()`
 * or `$node->nid->getValue()[0]["value"]`.
 *
 * @todo - If we just need the node object of the current page, we
 *   probably don't need to derive it. But what exactly is the reference
 *   to the current node?
 */

// Do we already know the NID?
function nodeFromNid(String $nid) {
  return \Drupal\node\Entity\Node::load($nid);
}

// Do we have access to a desired path?
function nodeFromPath(String $path) {
  // Ensure path, convert from alias if necessary.
  $path = \Drupal::services("path_alias.manager")->getPathByAlias($path);
  
  if(preg_match("/node\/(\d+)/", $path, $matches)) {
    return \Drupal\node\Entity\Node::load($matches[1]); 
  }
}