Programmatically get all names of an entity reference field

Question

Example: I want to get all tag names that are inside field_tags of node 5.

I can get the target_id with $node->field_tags->getValue();

But the problem is, I don't know what entity the target_id value belongs to. Could be a node id, term id, user id. Without that info, I am not able to use the target_id to get the name of the tag.

How can I get all the names of an entity reference field?

Answer 1

The easiest way to get what you want is something like this:

$names = [];
foreach ($node->field_tags as $item) {
  if ($item->entity) {
    $names[$item->entity->id()] = $item->entity->label();
  }
}

->entity is a so called computed property, it doesn't show up in getValues(). All reference fields have it.

And yes, forget about print_r() on entity or other complex objects. They contain objects that reference each other, and print_r() can't handle that. If you have an entity, always use print_r($entity->toArray()), then you get the field values only. You could install devel module or use a debugger, but that will give you the internal structure of an entity, which is not really want you want to see.

Answer 2

An entity reference field, by definition, can only target one entity type so you can know what your target type is by calling up getSetting() on the field definition.

// Print the targeted entity type field.
$field = \Drupal\field\Entity\FieldStorageConfig::loadByName('node','field_tags');
echo $field->getSetting('target_type');

Or better yet, use EntityReferenceFieldItemList::referencedEntities() to pull up the node's referenced entities and the associated data you need.

// Return an array of Entity objects referenced in the field.
$node->field_tags->referencedEntities();