Question

I’m trying to use the Rails Console to create object instances of my models.

It is possible to create and save an instance to the database using the manual methods like so:

1.9.3p125 :003 > subject = Subject.new
 => #<Subject id: nil, name: nil, position: nil, visible: false, created_at: nil, updated_at: nil> 
1.9.3p125 :004 > subject.name = "First Name"
 => "First Name" 
1.9.3p125 :005 > subject.position = 1
 => 1 
1.9.3p125 :006 > subject.visible = 'true'
 => "true" 
1.9.3p125 :007 > subject.save
(0.2ms)  BEGIN
SQL (0.6ms)  INSERT INTO `subjects` (`created_at`, `name`, `position`, `updated_at`, `visible`) VALUES ('2012-06-21 13:28:35', 'First Name', 1, '2012-06-21 13:28:35', 1)
(20.4ms)  COMMIT
 => true 
1.9.3p125 :008 > subject.id
 => 1 
1.9.3p125 :009 > subject.new_record?
 => false 

I’m totally new to RoR so I’ve got no idea where to begin trouble shooting this error:

1.9.3p125 :010 > subject = Subject.create(:name => "Second name", :position => 2)
ActiveModel::MassAssignmentSecurity::Error: Can't mass-assign protected attributes: name, position from /Users/Nick/.rvm/gems/ruby-1.9.3-p125/gems/activemodel-3.2.3/lib/active_model/mass_assignment_security/sanitizer.rb:48:in `process_removed_attributes'
from /Users/Nick/.rvm/gems/ruby-1.9.3-p125/gems/activemodel-3.2.3/lib/active_model/mass_assignment_security/sanitizer.rb:20:in `debug_protected_attribute_removal'
from /Users/Nick/.rvm/gems/ruby-1.9.3-p125/gems/activemodel-3.2.3/lib/active_model/mass_assignment_security/sanitizer.rb:12:in `sanitize'
from /Users/Nick/.rvm/gems/ruby-1.9.3-p125/gems/activemodel-3.2.3/lib/active_model/mass_assignment_security.rb:230:in `sanitize_for_mass_assignment'
from /Users/Nick/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.3/lib/active_record/attribute_assignment.rb:75:in `assign_attributes'
from /Users/Nick/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.3/lib/active_record/base.rb:498:in `initialize'
from /Users/Nick/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.3/lib/active_record/persistence.rb:44:in `new'
from /Users/Nick/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.3/lib/active_record/persistence.rb:44:in `create'
from (irb):10
from /Users/Nick/.rvm/gems/ruby-1.9.3-p125/gems/railties-3.2.3/lib/rails/commands/console.rb:47:in `start'
from /Users/Nick/.rvm/gems/ruby-1.9.3-p125/gems/railties-3.2.3/lib/rails/commands/console.rb:8:in `start'
from /Users/Nick/.rvm/gems/ruby-1.9.3-p125/gems/railties-3.2.3/lib/rails/commands.rb:41:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'

Here is my Subject model:

class Subject < ActiveRecord::Base
  attr_accessible :title, :body, :name, :position
end

Thanks!

Things I’ve tried so far:

1. Exiting and reentering rails c.
2. Typing “reload!” into rails c
3. Reopening terminal

Answer 1

You need to add

attr_accessible :name, :position

To your Subject model so you can create this in one step. Its a thing of security. You can read about this here:

http://api.rubyonrails.org/classes/ActiveModel/MassAssignmentSecurity/ClassMethods.html#method-i-attr_accessible

hf,..