Composite Reference
This module makes entity reference fields "composite," meaning the referenced entities are automatically deleted when the item referencing them is deleted. This is useful for ensuring data cleanup, but should typically be used for entities that are only referenced once.
The Composite Reference module allows users to mark entity reference fields as composite.
Composite reference fields ensure that referenced entities get deleted when the referencing entity is deleted.
The deletion is prevented if the referenced entity is referenced by another entity but typically you should ensure you only use this capability for entities that can be referenced only once.
How to
The module works with both Entity Reference and Entity Reference Revisions field types.
Field configs
For configurable (bundle) fields, edit the field configuration and check the box to mark the reference as composite. The rest is taken care of.
Base fields
For base fields, simply set a custom field setting on the entity reference or entity reference revision field definition, like so:
$fields['my_field'] = BaseFieldDefinition::create('entity_reference')
->setLabel(t('My reference'))
->setSettings([
'target_type' => 'node',
'composite_reference' => TRUE,
]);
If the base field gets overridden, this setting will get exported to the third party setting and it will continue to work.