How do I programmatically delete a reference field value?

Question

I have a multi-valued taxonomy reference field named field_classrooms in a node type. I use below code to delete the value in the field.

$node = Drupal\node\Entity\Node::load('1512');
unset($node->field_classrooms[0]);
$node->save();

I can't figure out what I am doing wrong here.

Answer 1

Maybe something like this could help you out

// Get the list of the associated classrooms ...
$classrooms = $node->get('field_classrooms')->getValue();
// ... if there are any associated classrooms ...
if(!empty($classrooms)) {
  foreach($classrooms as $classroom) {
    // ... get the key of the classroom
    $key = array_search(current($classroom), array_column($classrooms, key($classroom)));
    // ... remove the relationship ...
    $node->get('field_classrooms')->removeItem($key);
  }
  // ... and save the node.
  $node->save();
}

If you want to remove a single classroom from the list and you already know the tid

private function removeClassroomFromNode($node, $tid) {
  if(null != $node) {
    // ... get the list of associated classrooms
    $classrooms = $node->get('field_classrooms')->getValue();
    // ... get the key of the classroom
    $key = array_search($tid, array_column($classrooms, 'target_id'));
    // ... remove the classroom
    $node->get('field_classrooms')->removeItem($key);
    // ... save the node.
    $node->save();
  }
}

Answer 2

You can use below code for removing items in the reference field in Drupal 8 :

/** @var \Drupal\Core\Entity\ContentEntityBase $entity */
$entity = \Drupal::entityTypeManager()->getStorage('node')->load($nid);

$tids = $entity->get('field_classrooms')->getValue();

$updatedTerms = [];
foreach($tids as $term) {
  if ($term['target_id'] != 35)
    $updatedTerms[] = ['target_id' => $term['target_id']];      
}

$entity->field_notifications = $updatedTerms;

$entity->save();

Answer 3

You can simply set to empty

$node->set('field_classrooms', []);

Answer 4

You can remove the first item of a list just calling

$node->get('field_classrooms')->removeItem(0);

Answer 5

You can remove a particular referenced entity by id with this code:

    $entity->get('my_field')->setValue(array_filter($entity->get('my_field')->getValue(), function ($value) use ($id) {
      return ($value['target_id'] != $id);
    }));

Answer 6

Another way of bulk or selective delete is elegant filter() method.

Example:

use Drupal\Core\TypedData\TypedDataInterface;

$nodeStorage = \Drupal::service('entity_type.manager')->getStorage('node');
/**
 * @var \Drupal\node\Entity\Node $node
 */
$node = $nodeStorage->load($nid);
$classrooms = $node->get('field_classrooms');
$classrooms->filter(function (TypedDataInterface $item) {
  // You can do some operations on field item like: $item->getValue();
  // Returning TRUE in an iteration will remove the item.
  return TRUE;
});
$node->save();

Answer 7

Meanwhile you can take help from this code -

$node = \Drupal\node\Entity\Node::load('1512');
// Removes '0' index element.
$node->set('field_classrooms', array_slice($node->get('field_classrooms')->getValue(), 1));
$node->save();

Answer 8

the item is removed based on the index number of the list, so you need to figure out the index you want to remove,

1.- get all the referenced items

$array_of_referenced_items = $node->get('field_SOMETHING_ref')->getValue();

2.- search on the array for the index of the item you are trying to remove.

$index_to_remove = array_search(['target_id' => ID_TO_SEARCH], $array_of_referenced_items);

3.- Remove the reference by the index.

$node->get('field_SOMETHING_ref')->removeItem($index_to_remove);