How to determine if a beforeSave hook was called for update?

[tothewine]

Well, then I propose a feature request (low priority) to send an X-Header with the request type from the client js.

[yuri]

They are not distinguishable.

[tothewine]

if I want to find out if my php hook is being called as part of entity creation I do $entity->isNew();
But how do I differentiate if the entity is being edited with the 'Edit' button or by updating a single field?