I've been beating my head on this seemingly simple problem all evening and would appreciate any pointers.
I have an Admin model and an Assistant model, both subclasses of User, and with a HABTM relationship to each other (admins have many assistants, and one assistant may work for multiple admins).
I have a join table called admin_assistant with columns of admin_id and assistant_id.
In the form to create an Admin, I have:
<%= f.collection_select('assistant_id', @assistants_list, :id, :name ) %>
While displays fine, but when the controller create action tries to create the new Admin, I get:
Assistant expected, got String
The params have the ids for the selected assistants as an array of strings:
"admin"=>{"name"=>"Joe Smith", "assistants"=>["2", "3"], ...}
I've googled all over for this and it seems most people get this because the column name doesn't have _id, which I already have. But none of the examples I could find used HABTM relationships -- does this technique not work with the join table? What am I missing here?
Thanks for any pointers you can provide.
Michael