Hey all,
Following this Railscast (#17 HABTM Checkboxes - RailsCasts checkboxes) I have a set up a form with checkboxes that work great for updating records in a hatbm relationship.
But it only works if I'm doing an update to an existing record. When I try to create, I get a validation error.
In my app I have Sessions which can have many Learners. In the Session edit/create form there's a list of all the Learners with check boxes for selecting them.
I can edit a Session and check/uncheck Learners and the changes are saved. When I create a new session, I get a "Learners is invalid" validation error.
This is probably happening because the Learner ids can't be saved into the Learners_Sessions table without a session id, and the the session id isn't created until save. So when I do this:
def create @session = @user.project.sessions.new(params[:session]) if @session.save ....
it throws out the validation error.
Any ideas on how I can work around this? I could create a bare-bones Session object, save it and then update it with the full params, but that seems inelegant. I figure there has to be a better solution, I just don't know what it is.
Thanks,
Ian
