How to get a list of fields that are used in entities?

Question

I want to retrieve all fields that entities are using (including locked fields).

How can I get a list of fields that are used in entities?

Like we get in admin/reports/fields.

Answer 1

I would recommend EntityFieldManager::getFieldMap. The EntityManager is only a service to provide functions from other classes.

From documentation:

Return value

array An array keyed by entity type. Each value is an array which keys are field names and value is an array with two entries:

• type: The field type.
• bundles: An associative array of the bundles in which the field appears, where the keys and values are both the bundle's machine name.

Answer 2

EntityFieldManagerInterface::getFieldMap() produces a keyed array by entity type > field name with further information on the field type and its associated bundles.

$field_map = \Drupal::entityManager()->getFieldMap();
$node_field_map = $field_map['node'];
$node_fields = array_keys($node_field_map['node']);

There's also EntityFieldManagerInterface::getFieldDefinitions() if you want further field metadata. It produces an array of BaseFieldDefinition & FieldConfig objects that you can parse through for further detail.

  $node_article_fields  =\Drupal::entityManager()->getFieldDefinitions('node','article');

Answer 3

field_info_instance() would do what you want, though if you look in the docs you will see that in D8 it is deprecated in favour of

Field::fieldInfo()->getBundleInstance($entity_type, $bundle, $field_name).

Answer 4

Different ways to get field data:

Get a list of fields include base fields like nid. (contains entity type, bundle, field name and field type).

$field_map = \Drupal::entityTypeManager()->getFieldMap();
// Can also get by field type.
$field_map = \Drupal::entityTypeManager()->getFieldMapByFieldType('entity_reference');

Also see @shawn-conn's answer.

Get a list of storage fields and their data. (non-bundle specific - e.g. 'node.field_image')

// Get a list of storage fields
$field_config_ids = \Drupal::entityQuery('field_storage_config')
  // Allow access to all regardless of permissons.
  ->accessCheck(FALSE)
  ->condition('type', 'entity_reference')
  ->condition('status', 1)
  ->execute();

// Load all the fields.
$field_config_entities = \Drupal::entityTypeManager()->getStorage('field_storage_config')->loadMultipleOverrideFree($field_config_ids);

// Get where each config is used.
foreach (field_config_entities as $field_config_entity) {
  $bundles = $field_config_entity->getBundles();
}

Get a list of field instances and their data. (fields per bundle - e.g. 'node.story.field_image')

$field_config_ids = \Drupal::entityQuery('field_config')
  ->accessCheck(FALSE)
  ->condition('field_type', 'entity_reference')
  ->condition('status', 1)
  ->execute();
    
// Get also filter to only get feilds with a default value.
$field_config_ids = \Drupal::entityQuery('field_config')
  ->accessCheck(FALSE)
  ->condition('field_type', 'entity_reference')
  ->condition('status', 1)
  ->condition('default_value.0.target_uuid', NULL, 'IS NOT NULL')
  ->execute();
  
// Load the data.
$field_config_entities = \Drupal::entityTypeManager()->getStorage('field_config')->loadMultipleOverrideFree($field_config_ids);