Get a field instance's settings

Question

What's the equivalent of field_info_instance() for Drupal 8?

The default field settings are stored as configuration in a file like field.field.ENTITYTYPE.BUNDLE.FIELDNAME.yml, but how do I get their current value?

Answer 1

Using the entity_field.manager service, you are able to get an array of BaseFieldDefinition classes. This service is injectable as well, but for copy-paste working code, you can do the following:

$bundle_fields = \Drupal::getContainer()->get('entity_field.manager')->getFieldDefinitions($entity_type, $bundle);
$field_definition = $bundle_fields[$field_name];
$catalog_id = $field_definition->getSetting($setting_name);

Answer 2

Using a field instance:

$settings = $field->getFieldDefinition()->getSettings();

For example, in a field widget:

public function formElement(FieldItemListInterface $items, $delta, array $element, array &$form, FormStateInterface $form_state) {
  $element = [];

  // Get the settings.
  $settings = $items[$delta]->getFieldDefinition()->getSettings();

  // ... build render array

  return $element;
}

Answer 3

The most simple way to get field config is to use EntityTypeManager.

$entity_type = 'node';// node, taxonomy_term, taxonomy_vocabulary, ...
$bundle = 'article';// the content type machine name
$field = 'field_article_tags';// the field machine name

$fieldConfig =  \Drupal::entityTypeManager()
  ->getStorage('field_config')
  ->load($entity_type . '.' . $bundle . '.' . $field);

Answer 4

I wanted to get the Type and Label from the field definition. This did not work:

$setting_name = 'label';
$label = $field_definition->getSetting($setting_name);

This worked:

$label = $field_definition->getLabel();
$type = $field_definition->getType();