Programmatically rearrange order of entity reference list on node

Question

My content type has a node reference field that allows users to enter an unlimited amount of nodes in. I need to programmatically change what comes first in this list.

Using the code below I'm able to obtain the data from the field.

$node = \Drupal::entityTypeManager()->getStorage('node')->load($function);
$focus = $node->field_focus_area->getValue();

And it produces:

array(2) {
  [0]=>
  array(1) {
    ["target_id"]=>
    string(2) "31"
  }
  [1]=>
  array(1) {
    ["target_id"]=>
    string(3) "161"
  }
}

In order to rearrange it I tried doing

$newOrder[0] = ['target_id'=> 161]; 
$newOrder[1] = ['target_id'=> 31];

$focus->field_focus_area->rekey($newOrder);

But it was then when I realized that rekey was a protected function so I could use it. How would I programmatically rearrange the deltas (if that's what you'd call it) of an entity reference field programmatically?

Answer 1

After getting and rearranging the field data you can set it again:

$node->field_focus_area->setValue($newOrder);