Update in a has_many: though association.

Hello.
I need an advice to find a solution on creating a new has_many
:through association on a existing model.
I have:

Company
  has_many :managements, :dependent => :destroy
  has_many :managers, :through => :managements

Manager
  has_many :managements, :dependent => :destroy
  has_many :companies, :through => :managements

With the command
link_to "Add manager", new_company_manager_url(@company), :class =>
"btn", :remote => true

I display the manager form, create a new manager associated to the
company and create a new management.
In manager controller:

def create
    @company = Company.find(params[:company_id])
    @manager = Manager.new(params[:manager])
    add_management
    @manager.save
    respond_with @manager
end

private
  def add_management
    profile = params[:manager][:profile]
    profile.delete_if { |v| v.empty? }
    profile.each do |prof|
      @manager.managements.build(:profile => prof, :company => @company)
    end
  end

If the manager exists I only need to create a new management, so in
the manager new action I've put:

def new
    @company = Company.find(params[:company_id])
    @manager = Manager.find_or_initialize_by_fiscal_code(params[:fiscal_code])
    respond_with(@manager)
end

If the manager does not exists I create a new one and a new management
like showed before.
But, if the manager exists the form action is to update manager.
I'm searching for a solution to only create a new management without
updating manager.

Why can't you do what you want in the update action? If the details
of the manager record have not changed then the update will do
nothing.

Colin

Uhm it sounds strange to me creating a new management association in
the manager update action.
I mean update only to to update manger attributes.
Perhaps I'm wrong.

If you want to do it in the manager controller then update is the
correct action as changing the managements that it has is effectively
an update, even though this does not involve editing the manager
record itself. The other alternative is to put it in the create
action of the management controller. It is up to you which seems most
appropriate.

Colin