How do I make custom entity create new revision by default?

Question

I made a custom entity that extends RevisionableContentEntityBase. I can use the web interface to create entities. If I edit an entity and check the box Create new revision then a new revision will be created. There is no configuration form available to set the default for Create new revision.

The custom entity is quite simple. It has a few base fields and was built using drush generate module-content-entity.

How do I make my custom entity create a new revision by default?

Answer 1

Normally the default value is stored in bundle configurations. If you have no bundles then override getNewRevisionDefault() of your content entity form:

class MyEntityForm extends ContentEntityForm {

  protected function getNewRevisionDefault() {
    return TRUE;
  }

}

This class should already exist when you've generated the entity with Drush/Console. Check in the entity annotations that the class is used as form handler.

Answer 2

In addition to 4k4's answer here, which is very good and specific, a coworker helped me arrive at another solution in overriding ContentEntityForm::buildForm function:

class MyEntityForm extends ContentEntityForm {

  public function buildForm(array $form, FormStateInterface $form_state) {
    $form['revision'] = [
      '#type' => 'value',
      '#default_value' => TRUE,
    ];
  }
}

The benefit of overriding the buildForm function is you can have a bit more form-specific logic, e.g. making it a hidden value or a checkbox.