Annotations Type UI — Developer Reference

Developer-focused reference. For module overview, permissions, and config management see README.md.

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Extending annotation types with custom behaviors

AnnotationType implements ThirdPartySettingsInterface, allowing modules to attach their own properties to an annotation type without modifying the core entity.

A module that wants to add a behavior to annotation types (e.g. "expose this type in the front-end AI bot") does three things:

1. Declare a schema for the settings:

# config/schema/mymodule.schema.yml
annotations.annotation_type.*.third_party.mymodule:
  type: mapping
  label: 'My module annotation type settings'
  mapping:
    in_frontend_bot:
      type: boolean
      label: 'Show in front-end bot'

2. Inject a form element via hook_form_annotation_type_form_alter:

function mymodule_form_annotation_type_form_alter(array &$form, FormStateInterface $form_state): void {
  $type = $form_state->getFormObject()->getEntity();
  $form['in_frontend_bot'] = [
    '#type'          => 'checkbox',
    '#title'         => t('Show in front-end bot'),
    '#default_value' => $type->getThirdPartySetting('mymodule', 'in_frontend_bot', FALSE),
  ];
  $form['#entity_builders'][] = 'mymodule_form_annotation_type_form_builder';
}

function mymodule_form_annotation_type_form_builder(string $entity_type, AnnotationType $type, array &$form, FormStateInterface $form_state): void {
  $type->setThirdPartySetting('mymodule', 'in_frontend_bot', (bool) $form_state->getValue('in_frontend_bot'));
}

3. Read the setting wherever needed:

$show = $annotationType->getThirdPartySetting('mymodule', 'in_frontend_bot', FALSE);

The value is stored on the config entity alongside its first-party properties and exported with drush cex. From the editor's perspective the checkbox appears as part of the type edit form with no visible indication it comes from a different module.

This pattern is appropriate when the contributing module owns the full lifecycle of the behavior: it writes it, reads it, and acts on it. The annotations module's own services have no knowledge of third-party settings added by other modules.