Question

I make a carpooling application. When I want to create a new Route, I have this error:

ActiveModel::MassAssignmentSecurity::Error in RoutesController#create
Can't mass-assign protected attributes: place_ids

The Models are looking like this:

class Route < ActiveRecord::Base
  #  id             :integer         not null, primary key
  #  start_place_id :integer
  #  end_place_id   :integer
  #  start_time     :datetime
  #  end_time       :datetime
  #  car_id         :integer
  belongs_to :car
  has_many :places
  has_and_belongs_to_many :users
  attr_accessible :start_place_id, :end_place_id, :start_time, :end_time, :car_id
end

class Place < ActiveRecord::Base
  has_many :routes
  attr_accessible :name, :address, :lat, :long, :description
end

class Car < ActiveRecord::Base
  has_many :routes
  attr_accessible :car_type, :license_plate, :seats_num, :motorway_vignette_expeier
end

The _form.html.erb of the Routes looking like this:

<%= simple_form_for @route do |f| %>
  <%= render 'shared/error_messages', :object => f.object %>
  <%= f.association :places %>
  <%= f.association :places %>
  <%= f.input :start_time %>
  <%= f.input :end_time %>
  <%= f.association :car %>
  <%= f.button :submit %>
<% end %>

The log is writing this:

Started POST "/routes" for 127.0.0.1 at 2012-03-23 15:41:37 +0100
Processing by RoutesController#create as HTML
  Parameters: {"utf8"=>"✓", "route"=>{"place_ids"=>["", "4", "", "1"], "start_time(1i)"=>"2012", "start_time(2i)"=>"3", "start_time(3i)"=>"23", "start_time(4i)"=>"14", "start_time(5i)"=>"41", "end_time(1i)"=>"2012", "end_time(2i)"=>"3", "end_time(3i)"=>"23", "end_time(4i)"=>"14", "end_time(5i)"=>"41", "car_id"=>"1"}, "commit"=>"Create Route"}
Completed 500 Internal Server Error in 1ms

ActiveModel::MassAssignmentSecurity::Error (Can't mass-assign protected attributes: place_ids):
  app/controllers/routes_controller.rb:15:in `new'
  app/controllers/routes_controller.rb:15:in `create'

I don’t understand, why it makes a 4 element long array for place_ids (“place_ids”=>[“”, “4”, “”, “1”], ).
And I don’t understand, why it write MassAssignment, when I wrote in the model attr_accessible…
I did similar in rails 3.0.0, and it worked. I think simple_form changed something…
Why he write place_ids? Why not start_place_id and end_place_id?

I uploaded the full project to github: https://github.com/Koli14/telekocsi2

The environment is:

ruby 1.9.2p290

Rails 3.2.1

simple_form (2.0.1)

Ubuntu 11.10

Answer 1

I think you probably want another look at your associations. It seems to me that a route should belong to an end place and belong to a start place rather than have many places (unless you are including waypoints). A clue that this may be the case is the foreign keys in your route model.