Question

I am following Lynda ruby on rails tutorial.

Here is the code I have to run “subject = Subject.new(:name => “First Subject”, :position => 1, :visible => true)”

This is my error message:

ActiveModel::MassAssignmentSecurity::Error: Can't mass-assign protected attributes: name, position, visible
    from /Users/lexi87/.rvm/gems/ruby-1.9.2-p320/gems/activemodel-3.2.9/lib/active_model/mass_assignment_security/sanitizer.rb:48:in `process_removed_attributes'
    from /Users/lexi87/.rvm/gems/ruby-1.9.2-p320/gems/activemodel-3.2.9/lib/active_model/mass_assignment_security/sanitizer.rb:20:in `debug_protected_attribute_removal'
    from /Users/lexi87/.rvm/gems/ruby-1.9.2-p320/gems/activemodel-3.2.9/lib/active_model/mass_assignment_security/sanitizer.rb:12:in `sanitize'
    from /Users/lexi87/.rvm/gems/ruby-1.9.2-p320/gems/activemodel-3.2.9/lib/active_model/mass_assignment_security.rb:230:in `sanitize_for_mass_assignment'
    from /Users/lexi87/.rvm/gems/ruby-1.9.2-p320/gems/activerecord-3.2.9/lib/active_record/attribute_assignment.rb:75:in `assign_attributes'
    from /Users/lexi87/.rvm/gems/ruby-1.9.2-p320/gems/activerecord-3.2.9/lib/active_record/base.rb:497:in `initialize'
    from (irb):9:in `new'
    from (irb):9
    from /Users/lexi87/.rvm/gems/ruby-1.9.2-p320/gems/railties-3.2.9/lib/rails/commands/console.rb:47:in `start'
    from /Users/lexi87/.rvm/gems/ruby-1.9.2-p320/gems/railties-3.2.9/lib/rails/commands/console.rb:8:in `start'
    from /Users/lexi87/.rvm/gems/ruby-1.9.2-p320/gems/railties-3.2.9/lib/rails/commands.rb:41:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'

Here is my subject.rb from models:

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

Answer 1

You are need to uncomment attr_accessible, line which starts with # character ignored by the interpreter

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

Can’t mass-assign protected attributes: name, position, visible

attr_accessible specifies a list of attributes that can be set via mass-assignment.