Question

So I have a flow model and a page model

Each flow has_many pages and each page belongs_to a flow

Flow model

class Flow < ActiveRecord::Base
has_many :pages, :dependent => :destroy
accepts_nested_attributes_for :pages, :reject_if => lambda { |p| p[:path].blank?}, :allow_destroy => true
end

Page model

class Page < ActiveRecord::Base
  belongs_to :flow
end

Then in the new flow action I have this

def new
    @flow = Flow.new
    3.times do
      page = @flow.pages.build
    end
    respond_to do |format|
      format.html # new.html.erb
      format.json { render json: @flow }
    end
  end

but I keep getting the error: “unknown attribute: flow_id”?

Answer 1

Use generate migration add_flow_id_to_page flow_id:integer to generate the foreign key column.