When does the Doctrine prePersist event run?

In a nutshell

The prePersist event is dispatched just before Doctrine performs the actual persist operation (i.e., just before the entity is about to be inserted into the database).

Other notes

Doctrine will not recognize changes made to relations in the prePersist event. This includes modifications to collections such as additions, removals, or replacements.

Sources

• prePersist – Doctrine docs