Why does update_attributes break my Rails app? - ruby-on-rails

Question

Original Question
I'm running Rails 3.0.1 on Ruby 1.9.2. Here are the relevant model, controller, and view.
Code
user.rb:
class User < ActiveRecord::Base
belongs_to :directory
attr_accessor :new_password, :new_password_confirmation
validates_confirmation_of :new_password, :if => :password_changed?
before_save :hash_password, :if => :password_changed?
def self.authenticate(login, password)
# Check to see if the user exists
if user = find_by_login(login)
# If this is an directory user, authenticate them against their directory
if user.directory
return directory_auth user, password
# Otherwise, authenticate them against the local database
elsif user.hash == Digest::SHA2.hexdigest(user.salt + password)
return user
end
end
return nil
end
def password_changed?
!#new_password.blank?
end
private
def hash_password
self.salt = ActiveSupport::SecureRandom.base64 8
self.hash = Digest::SHA2.hexdigest(self.salt + #new_password)
end
def self.directory_auth(user, password)
directory = user.directory
directory.bind['%s'] = user.login
ldap = Net::LDAP.new
if directory.use_simple_tls?
ldap.encryption :simple_tls
end
ldap.host = directory.host
ldap.port = directory.port
ldap.auth directory.bind, password
return user if ldap.bind
return nil
end
end
users_controller.rb:
class UsersController < ApplicationController
def index
#users = User.all
end
def show
#user = User.find params[:id]
end
def new
#user = User.new
end
def create
#user = User.new params[:user]
if #user.save
flash[:notice] = "#{#user.login} was created"
redirect_to #user
else
flash[:notice] = 'The user could not be created'
render :action => 'new'
end
end
def edit
#user = User.find params[:id]
end
def update
#user = User.find params[:id]
#user.attributes = params[:user] # this works
# #user.update_attributes params[:user] # this does NOT work
if #user.save # I realize this is redundant if update_attributes is working
flash[:notice] = "#{#user.login} was updated"
redirect_to #user
else
flash[:notice] = 'The user could not be updated'
render :action => 'edit'
end
end
def destroy
#user = User.find params[:id]
#user.destroy
flash[:notice] = "#{#user.login} was deleted"
redirect_to users_url
end
end
users.html.erb:
<%= form_for #user do |f| %>
<%= f.label :login %>:
<%= f.text_field :login %>
<br>
<%= f.label :new_password %>:
<%= f.password_field :new_password %>
<br>
<%= f.label :new_password_confirmation %>:
<%= f.password_field :new_password_confirmation %>
<br>
<% if directories = Directory.all.empty? %>
No directories defined. You can <%= link_to 'add a directory', new_directory_path %>.
<% else %>
<%= f.label :directory_id %>:
<%= f.collection_select :directory_id, Directory.all, :id, :name, { :include_blank => 'None' } %>
<% end %>
<br>
<%= f.label :admin, 'Administrator?' %>:
<%= f.check_box :admin %>
<br>
<%= f.submit %>
<% end %>
schema.rb:
ActiveRecord::Schema.define(:version => 20101107005603) do
create_table "directories", :force => true do |t|
t.string "host"
t.string "bind"
t.boolean "use_simple_tls"
t.integer "port"
t.string "name"
t.datetime "created_at"
t.datetime "updated_at"
end
create_table "users", :force => true do |t|
t.string "login"
t.string "hash"
t.string "salt"
t.boolean "admin"
t.integer "directory_id"
t.datetime "created_at"
t.datetime "updated_at"
end
end
I have another model/controller/view for directories that is very similar, but doesn't have virtual accessors or other model ids, and update_attributes works fine in it. I did a quick test app with rails g scaffold users name:string password:string and all CRUD actions work fine.
This was driving me nuts! I found a workaround, but I really want to understand why update_attributes doesn't work here. When I run the update action, I get this:
TypeError in UsersController#update
can't convert nil into Integer
Rails.root: /home/force/proj
app/controllers/users_controller.rb:34:in `update'
Full Stack Trace
activerecord (3.0.1) lib/active_record/connection_adapters/abstract/database_statements.rb:318:in `uniq'
activerecord (3.0.1) lib/active_record/connection_adapters/abstract/database_statements.rb:318:in `commit_transaction_records'
activerecord (3.0.1) lib/active_record/connection_adapters/abstract/database_statements.rb:165:in `transaction'
activerecord (3.0.1) lib/active_record/transactions.rb:204:in `transaction'
activerecord (3.0.1) lib/active_record/transactions.rb:287:in `with_transaction_returning_status'
activerecord (3.0.1) lib/active_record/persistence.rb:126:in `update_attributes'
app/controllers/users_controller.rb:34:in `update'
actionpack (3.0.1) lib/action_controller/metal/implicit_render.rb:4:in `send_action'
actionpack (3.0.1) lib/abstract_controller/base.rb:150:in `process_action'
actionpack (3.0.1) lib/action_controller/metal/rendering.rb:11:in `process_action'
actionpack (3.0.1) lib/abstract_controller/callbacks.rb:18:in `block in process_action'
activesupport (3.0.1) lib/active_support/callbacks.rb:435:in `_run__805567340__process_action__482539529__callbacks'
activesupport (3.0.1) lib/active_support/callbacks.rb:409:in `_run_process_action_callbacks'
activesupport (3.0.1) lib/active_support/callbacks.rb:93:in `run_callbacks'
actionpack (3.0.1) lib/abstract_controller/callbacks.rb:17:in `process_action'
actionpack (3.0.1) lib/action_controller/metal/instrumentation.rb:30:in `block in process_action'
activesupport (3.0.1) lib/active_support/notifications.rb:52:in `block in instrument'
activesupport (3.0.1) lib/active_support/notifications/instrumenter.rb:21:in `instrument'
activesupport (3.0.1) lib/active_support/notifications.rb:52:in `instrument'
actionpack (3.0.1) lib/action_controller/metal/instrumentation.rb:29:in `process_action'
actionpack (3.0.1) lib/action_controller/metal/rescue.rb:17:in `process_action'
actionpack (3.0.1) lib/abstract_controller/base.rb:119:in `process'
actionpack (3.0.1) lib/abstract_controller/rendering.rb:40:in `process'
actionpack (3.0.1) lib/action_controller/metal.rb:133:in `dispatch'
actionpack (3.0.1) lib/action_controller/metal/rack_delegation.rb:14:in `dispatch'
actionpack (3.0.1) lib/action_controller/metal.rb:173:in `block in action'
actionpack (3.0.1) lib/action_dispatch/routing/route_set.rb:62:in `call'
actionpack (3.0.1) lib/action_dispatch/routing/route_set.rb:62:in `dispatch'
actionpack (3.0.1) lib/action_dispatch/routing/route_set.rb:27:in `call'
rack-mount (0.6.13) lib/rack/mount/route_set.rb:148:in `block in call'
rack-mount (0.6.13) lib/rack/mount/code_generation.rb:93:in `block in recognize'
rack-mount (0.6.13) lib/rack/mount/code_generation.rb:103:in `optimized_each'
rack-mount (0.6.13) lib/rack/mount/code_generation.rb:92:in `recognize'
rack-mount (0.6.13) lib/rack/mount/route_set.rb:139:in `call'
actionpack (3.0.1) lib/action_dispatch/routing/route_set.rb:492:in `call'
actionpack (3.0.1) lib/action_dispatch/middleware/best_standards_support.rb:17:in `call'
actionpack (3.0.1) lib/action_dispatch/middleware/head.rb:14:in `call'
rack (1.2.1) lib/rack/methodoverride.rb:24:in `call'
actionpack (3.0.1) lib/action_dispatch/middleware/params_parser.rb:21:in `call'
actionpack (3.0.1) lib/action_dispatch/middleware/flash.rb:182:in `call'
actionpack (3.0.1) lib/action_dispatch/middleware/session/abstract_store.rb:149:in `call'
actionpack (3.0.1) lib/action_dispatch/middleware/cookies.rb:287:in `call'
activerecord (3.0.1) lib/active_record/query_cache.rb:32:in `block in call'
activerecord (3.0.1) lib/active_record/connection_adapters/abstract/query_cache.rb:28:in `cache'
activerecord (3.0.1) lib/active_record/query_cache.rb:12:in `cache'
activerecord (3.0.1) lib/active_record/query_cache.rb:31:in `call'
activerecord (3.0.1) lib/active_record/connection_adapters/abstract/connection_pool.rb:355:in `call'
actionpack (3.0.1) lib/action_dispatch/middleware/callbacks.rb:46:in `block in call'
activesupport (3.0.1) lib/active_support/callbacks.rb:415:in `_run_call_callbacks'
actionpack (3.0.1) lib/action_dispatch/middleware/callbacks.rb:44:in `call'
rack (1.2.1) lib/rack/sendfile.rb:107:in `call'
actionpack (3.0.1) lib/action_dispatch/middleware/remote_ip.rb:48:in `call'
actionpack (3.0.1) lib/action_dispatch/middleware/show_exceptions.rb:46:in `call'
railties (3.0.1) lib/rails/rack/logger.rb:13:in `call'
rack (1.2.1) lib/rack/runtime.rb:17:in `call'
activesupport (3.0.1) lib/active_support/cache/strategy/local_cache.rb:72:in `call'
rack (1.2.1) lib/rack/lock.rb:11:in `block in call'
:10:in `synchronize'
rack (1.2.1) lib/rack/lock.rb:11:in `call'
actionpack (3.0.1) lib/action_dispatch/middleware/static.rb:30:in `call'
railties (3.0.1) lib/rails/application.rb:168:in `call'
railties (3.0.1) lib/rails/application.rb:77:in `method_missing'
railties (3.0.1) lib/rails/rack/log_tailer.rb:14:in `call'
rack (1.2.1) lib/rack/content_length.rb:13:in `call'
rack (1.2.1) lib/rack/handler/webrick.rb:52:in `service'
/home/force/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/webrick/httpserver.rb:111:in `service'
/home/force/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/webrick/httpserver.rb:70:in `run'
/home/force/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/webrick/server.rb:183:in `block in start_thread'
Request Parameters
{"utf8"=>"✓",
"_method"=>"put",
"authenticity_token"=>"OvMUeM9hqfPASC0NS+Th07GELu6B+dQCCTtm3gWdJE4=",
"user"=>{"login"=>"local",
"new_password"=>"[FILTERED]",
"new_password_confirmation"=>"[FILTERED]",
"directory_id"=>"",
"admin"=>"0"},
"commit"=>"Update User",
"id"=>"13"}
Full Source Code
If you'd like to give it a try, you can download the full source at http://github.com/sidewaysmilk/deezy and edit app/controllers/users_controller.rb to use #user.update_attributes params[:user] in the update action.

Answer 1

OK. I feel really stupid. I'm surprised nobody caught this.
In my model, I name one of my attributes. hash, so to access it, I would say #user.hash.
ActiveRecord::Base#hash is already defined!
So I screwed up. When ActiveRecord was attempting to execute the transaction, it was trying to set a value like
#user.hash = password_hash
ActiveRecord::Base#hash= expects an integer, and password_hash outputs a String if the password is changed, and nil otherwise.
So never name a column hash! Check the documentation when you're picking column names to avoid collisions.

Answer 2

It looks like what may be the problem is that the user id is a primary key and somehow that is being attempted to be updated. What is the error message you get if you use the 'bangversion ofupdate_attributes:update_attributes!` ?

Answer 3

Without a full stack trace it's hard to say, but the error message "can't convert nil into Integer" is your key thing to track down. Likewise we want see the logs for a request that's failing. I think the Parameters: line of the log might shed light on the issue.
Update Below:
Can you pass the same params successfully to #user.update_attributes in the rails console?
rails console
user = User.find(42) # whatever a good test user's id is
user_params = {"login"=>"local", "new_password"=>"supersecret", "new_password_confirmation"=>"supersecret", "directory_id"=>"", "admin"=>"0"}
user.update_attributes!(user_params)
Does that behave any differently?