Trigger update on entity when adding a related entity

[yuri]

Hi,

You need to create a hook (see developer docs) for a product entity type and check whether category is changed.

$entity->isAttributeChanged('categoryId').

[alexS]

Hey guys,

I have a product entity that can have multiple categories (which are set as related entities).
Anyone know how can I set an updated flag on the product every time I link a new category?

Thanks