Rails_admin: How to delete nested objects in rails 4?

问题

I am having:

class Entity < AR::Base
  has_many :representatives, 
    inverse_of: :entity, dependent: :destroy

  accepts_nested_attributes_for :representatives, 
    allow_destroy: true
end

and the Entity's rails admin form allows me to create nested representatives inline. Though, I am unable to remove representatives through the entity's nested form after they are already saved. I am suspicious that this is related with rails 4 since there are other similar questions with answers that do not work:

Rails Admin - removing a related object

来源：https://stackoverflow.com/questions/25727474/rails-admin-how-to-delete-nested-objects-in-rails-4