Hi there!
I started learning Rails using the guides.rubyonrails.org/*
documentation, and I have started a simple project with only two model
classes so start with. However, I’ve came across some errors, and with
some trial I got it working. I have a final question about the error
“Can’t mass-assign protected attributes”, but first some version
numbers and what I did:
% rails --version
Rails 3.2.3
% rails new testapp
% cd testapp
% rails g scaffold project name:string file:binary
% rails g scaffold auction name:string begin:datetime
project:references
% rake db:migrate
== CreateProjects: migrating
– create_table(:projects)
→ 0.0014s
== CreateProjects: migrated (0.0015s)
== CreateAuctions: migrating
– create_table(:auctions)
→ 0.0010s
– add_index(:auctions, :project_id)
→ 0.0004s
== CreateAuctions: migrated (0.0015s)
% rails c
Loading development environment (Rails 3.2.3)
irb(main):002:0> p = Project.new(name: “test”, file:“fff”)
=> #<Project id: nil, name: “test”, file: “fff”, created_at: nil,
updated_at: nil>
irb(main):003:0> p.save()
=> true
irb(main):010:0> Auction.new(:name => “tzap”, :begin =>
nil, :project_id => 1)
ActiveModel::MassAssignmentSecurity::Error: Can’t mass-assign
protected attributes: project_id
from /usr/local/Cellar/ruby/1.9.3-p194/lib/ruby/gems/1.9.1/gems/
activemodel-3.2.3/lib/active_model/mass_assignment_security/
sanitizer.rb:48:in process_removed_attributes' from /usr/local/Cellar/ruby/1.9.3-p194/lib/ruby/gems/1.9.1/gems/ activemodel-3.2.3/lib/active_model/mass_assignment_security/ sanitizer.rb:20:in debug_protected_attribute_removal’
from /usr/local/Cellar/ruby/1.9.3-p194/lib/ruby/gems/1.9.1/gems/
activemodel-3.2.3/lib/active_model/mass_assignment_security/
sanitizer.rb:12:in sanitize' from /usr/local/Cellar/ruby/1.9.3-p194/lib/ruby/gems/1.9.1/gems/ activemodel-3.2.3/lib/active_model/mass_assignment_security.rb:230:in sanitize_for_mass_assignment’
from /usr/local/Cellar/ruby/1.9.3-p194/lib/ruby/gems/1.9.1/gems/
activerecord-3.2.3/lib/active_record/attribute_assignment.rb:75:in
assign_attributes' from /usr/local/Cellar/ruby/1.9.3-p194/lib/ruby/gems/1.9.1/gems/ activerecord-3.2.3/lib/active_record/base.rb:498:in initialize’
from (irb):10:in new' from (irb):10 from /usr/local/Cellar/ruby/1.9.3-p194/lib/ruby/gems/1.9.1/gems/ railties-3.2.3/lib/rails/commands/console.rb:47:in start’
from /usr/local/Cellar/ruby/1.9.3-p194/lib/ruby/gems/1.9.1/gems/
railties-3.2.3/lib/rails/commands/console.rb:8:in start' from /usr/local/Cellar/ruby/1.9.3-p194/lib/ruby/gems/1.9.1/gems/ railties-3.2.3/lib/rails/commands.rb:41:in <top (required)>’
from script/rails:6:in require' from script/rails:6:in ’
==> So I added :project_id to the model:
% cat app/models/auction.rb
class Auction < ActiveRecord::Base
belongs_to :project
attr_accessible :begin, :name, :project_id
^^^^^^^^^
end
And this time is working from the console:
% rails c
Loading development environment (Rails 3.2.3)
irb(main):001:0> Project.all
Project Load (0.1ms) SELECT “projects”.* FROM “projects”
=> [#<Project id: 1, name: “test”, file: “fff”, created_at:
“2012-05-05 13:05:44”, updated_at: “2012-05-05 13:05:44”>]
irb(main):008:0> a = Auction.new(:name => “foo”, :begin =>
nil, :project_id => 1)
=> #<Auction id: nil, name: “foo”, begin: nil, project_id: 1,
created_at: nil, updated_at: nil>
irb(main):009:0> a.save()
=> true
% rails s
1 => trying to add an auction using the front end:
http://dl.dropbox.com/u/8724298/Screen%20Shot%202012-05-05%20at%203.44.19%20PM.png
2 => I receive another error:
ActiveModel::MassAssignmentSecurity::Error in
AuctionsController#create
Can’t mass-assign protected attributes: project
Rails.root: /private/tmp/testapp
Application Trace | Framework Trace | Full Trace
app/controllers/auctions_controller.rb:43:in new' app/controllers/auctions_controller.rb:43:in create’
Request
Parameters:
{“utf8”=>“✓”,
“authenticity_token”=>“0gcU4dbRGsgmiXGEcMKO1o1Oec6GoGQ4OziwNbRyfoc=”,
“auction”=>{“name”=>“FFF”,
“begin(1i)”=>“2012”,
“begin(2i)”=>“5”,
“begin(3i)”=>“5”,
“begin(4i)”=>“13”,
“begin(5i)”=>“44”,
“project”=>“1”},
“commit”=>“Create Auction”}
[
http://dl.dropbox.com/u/8724298/Screen%20Shot%202012-05-05%20at%203.44.19%20PM.png
]
Where am I wrong?
Thank you!