How can I setRequired() for a BaseFieldDefinition per entity bundle?

Question

I have an entity type animal with the following bundles:

• cow
• pig
• sparrow
• anteater

In the Animal.php entity type definition, I create some base fields, one of which is an entity reference to Habitat.

BaseFieldDefinition::create('entity_reference')
  ->setLabel(t('Habitat ID'))
  ->setCardinality(1)
  ->setSetting('target_type', 'habitat')
  ->setDisplayConfigurable('form', FALSE)
  ->setDisplayConfigurable('view', TRUE);

I want to require this entity reference for cows and pigs, but I don't want it to be required for sparrows and anteaters.

So, I can't use ->setRequired() in BaseFieldDefinition::create() because that will apply to all the bundles.

What's the simplest way to require a field created by BaseFieldDefinition::create() in some bundles but not others?

Answer 1

I haven't done it, but I believe you can override ContentEntityBase::bundleFieldDefinitions(), returning the fields based on the bundle type.