Create Model Through Text Field

Question

I watched this Railscast on "Create Model Through Text Field" because I want a user to have the option of either selecting an existing project or creating a new one in a form. I followed along, but it's still not working for me. I have my code setup exactly as the video suggests:

Form:

<%= f.label :project_id %><br>
<%= f.collection_select :project_id, Project.order(:name), :id, :name, :prompt => "Select a project" %>
or create one:
<%= f.text_field :new_project_name %>

Model that form is for:

class Item < ActiveRecord::Base
    belongs_to :project
    attr_accessor :new_project_name
    before_save :create_project_from_name

    def create_project_from_name
        create_project(:name => new_project_name) unless new_project_name.blank?
    end
end

Project Model

class Project < ActiveRecord::Base
    has_many :items
end

Why is this not working for me?

Answer 1

For Item, you are specifying:

belongs_to :factory_project

and are using create_project.

Use belongs_to :project.

Answer 2

I figured it out. It needed to be in my permitted parameters.