accepts_nested_attributes_for :has_many :through => 'bug?'

rubyonrails-talk
#1

Hey guys & ladies!

I've got the following relationship which i'm trying to get
accepts_nested_attributes to work with. But when i submit my form, it
looks as if its expecting a Company object, rather than an array of
companies. which really doesn't make sense considering its a
has_many :relationship.

So what i'm after, is a way to
accept_nested_attributes_for :companies, so when my users sign up to
the website, they can also create a company.

-------------- user.rb

class User < ActiveRecord::Base
  has_many :company_users
  has_many :companies, :through => :company_users

  accepts_nested_attributes_for :companies
end

-------------- company.rb

class Company < ActiveRecord::Base
  has_many :company_users
  has_many :users, :through => :company_users
end

-------------- company_user.rb
class CompanyUser < ActiveRecord::Base
  belongs_to :user
  belongs_to :company
end

-------------- My form

<% form_for :user, :url => users_path do |f| -%>

<p><%= label_tag 'First name' %>
<%= f.text_field :firstname %></p>

<p><%= label_tag 'Surname' %>
<%= f.text_field :surname %></p>

<p><%= label_tag 'email' %>
<%= f.text_field :email %></p>

<p><%= label_tag 'password' %>
<%= f.password_field :password %></p>

<p><%= label_tag 'password_confirmation', 'Confirm Password' %>
<%= f.password_field :password_confirmation %></p>

  <h2>Company Information</h2>
  <% f.fields_for :companies do |company| %>
       <%= render 'companies/fields', :f => company %>
   <% end %>

<p class="submit"><%= submit_tag 'Sign up' %></p>
<% end -%>

-------------- The error

ActiveRecord::AssociationTypeMismatch in UsersController#create

Company(#2180266380) expected, got Array(#2148226700)

RAILS_ROOT: /Users/mark/Programming/ruby/s/

/Library/Ruby/Gems/1.8/gems/activerecord-2.3.4/lib/active_record/
associations/association_proxy.rb:263:in `raise_on_type_mismatch'
/Library/Ruby/Gems/1.8/gems/activerecord-2.3.4/lib/active_record/
associations/association_collection.rb:320:in `replace'
/Library/Ruby/Gems/1.8/gems/activerecord-2.3.4/lib/active_record/
associations/association_collection.rb:320:in `each'
/Library/Ruby/Gems/1.8/gems/activerecord-2.3.4/lib/active_record/
associations/association_collection.rb:320:in `replace'
/Library/Ruby/Gems/1.8/gems/activerecord-2.3.4/lib/active_record/
associations.rb:1322:in `companies='
/Library/Ruby/Gems/1.8/gems/activerecord-2.3.4/lib/active_record/
base.rb:2744:in `send'
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base.rb:2744:in `attributes='
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base.rb:2740:in `each'
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base.rb:2740:in `attributes='
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core_ext/benchmark.rb:17:in `ms'
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filters.rb:606:in `process'
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base.rb:391:in `process'
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27:in `new'
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27:in `create'
/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/
1.8/benchmark.rb:308:in `realtime'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/
dispatcher.rb:87:in `dispatch'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/
dispatcher.rb:121:in `_call'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/
dispatcher.rb:130:in `build_middleware_stack'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/
dispatcher.rb:114:in `call'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/
dispatcher.rb:108:in `call'

/Library/Ruby/Gems/1.8/gems/activerecord-2.3.4/lib/active_record/
associations/association_proxy.rb:263:in `raise_on_type_mismatch'
/Library/Ruby/Gems/1.8/gems/activerecord-2.3.4/lib/active_record/
associations/association_collection.rb:320:in `replace'
/Library/Ruby/Gems/1.8/gems/activerecord-2.3.4/lib/active_record/
associations/association_collection.rb:320:in `each'
/Library/Ruby/Gems/1.8/gems/activerecord-2.3.4/lib/active_record/
associations/association_collection.rb:320:in `replace'
/Library/Ruby/Gems/1.8/gems/activerecord-2.3.4/lib/active_record/
associations.rb:1322:in `companies='
/Library/Ruby/Gems/1.8/gems/activerecord-2.3.4/lib/active_record/
base.rb:2744:in `send'
/Library/Ruby/Gems/1.8/gems/activerecord-2.3.4/lib/active_record/
base.rb:2744:in `attributes='
/Library/Ruby/Gems/1.8/gems/activerecord-2.3.4/lib/active_record/
base.rb:2740:in `each'
/Library/Ruby/Gems/1.8/gems/activerecord-2.3.4/lib/active_record/
base.rb:2740:in `attributes='
/Library/Ruby/Gems/1.8/gems/activerecord-2.3.4/lib/active_record/
base.rb:2438:in `initialize'
/Users/mark/Programming/ruby/s/app/controllers/users_controller.rb:
27:in `new'
/Users/mark/Programming/ruby/s/app/controllers/users_controller.rb:
27:in `create'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/
base.rb:1331:in `send'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/
base.rb:1331:in `perform_action_without_filters'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/
filters.rb:617:in `call_filters'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/
filters.rb:610:in `perform_action_without_benchmark'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/
benchmarking.rb:68:in `perform_action_without_rescue'
/Library/Ruby/Gems/1.8/gems/activesupport-2.3.4/lib/active_support/
core_ext/benchmark.rb:17:in `ms'
/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/
1.8/benchmark.rb:308:in `realtime'
/Library/Ruby/Gems/1.8/gems/activesupport-2.3.4/lib/active_support/
core_ext/benchmark.rb:17:in `ms'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/
benchmarking.rb:68:in `perform_action_without_rescue'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/
rescue.rb:160:in `perform_action_without_flash'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/
flash.rb:146:in `perform_action'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/
base.rb:532:in `send'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/
base.rb:532:in `process_without_filters'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/
filters.rb:606:in `process'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/
base.rb:391:in `process'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/
base.rb:386:in `call'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/
routing/route_set.rb:437:in `call'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/
dispatcher.rb:87:in `dispatch'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/
dispatcher.rb:121:in `_call'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/
dispatcher.rb:130:in `build_middleware_stack'
/Library/Ruby/Gems/1.8/gems/activerecord-2.3.4/lib/active_record/
query_cache.rb:29:in `call'
/Library/Ruby/Gems/1.8/gems/activerecord-2.3.4/lib/active_record/
query_cache.rb:29:in `call'
/Library/Ruby/Gems/1.8/gems/activerecord-2.3.4/lib/active_record/
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/Library/Ruby/Gems/1.8/gems/activerecord-2.3.4/lib/active_record/
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/Library/Ruby/Gems/1.8/gems/activerecord-2.3.4/lib/active_record/
query_cache.rb:28:in `call'
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`synchronize'
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/Library/Ruby/Gems/1.8/gems/actionpack-2.3.4/lib/action_controller/
dispatcher.rb:114:in `call'
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spawn_manager.rb:262:in `spawn_rails_application'
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abstract_server_collection.rb:126:in `lookup_or_add'
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spawn_manager.rb:256:in `spawn_rails_application'
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abstract_server_collection.rb:80:in `synchronize'
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abstract_server_collection.rb:79:in `synchronize'
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spawn_manager.rb:255:in `spawn_rails_application'
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spawn_manager.rb:154:in `spawn_application'
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spawn_manager.rb:287:in `handle_spawn_application'
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abstract_server.rb:352:in `__send__'
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abstract_server.rb:352:in `main_loop'
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abstract_server.rb:196:in `start_synchronously'
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61

Request

Parameters:

{"commit"=>"Sign up",
"user"=>{"password_confirmation"=>"12341234",
"companies"=>{"name"=>"1234"},
"firstname"=>"driver",
"surname"=>"asdf",
"password"=>"12341234",
"email"=>"asdf@asdf.com"}}

Show session dump

#2

Hey guys & ladies!

I've got the following relationship which i'm trying to get
accepts_nested_attributes to work with. But when i submit my form, it
looks as if its expecting a Company object, rather than an array of
companies. which really doesn't make sense considering its a
has_many :relationship.

So what i'm after, is a way to
accept_nested_attributes_for :companies, so when my users sign up to
the website, they can also create a company.

[snip]

Parameters:

{"commit"=>"Sign up",
"user"=>{"password_confirmation"=>"12341234",
"companies"=>{"name"=>"1234"},
"firstname"=>"driver",
"surname"=>"asdf",
"password"=>"12341234",
"email"=>"a...@asdf.com"}}

Your models and forms look OK, but something has gone wrong in the
generated HTML code - the 'companies' key should be
'companies_attributes' to trigger the nested attributes stuff. Can you
post the generated HTML?

--Matt Jones

#3

Thanks for having a look Matt, I've changed

<% f.fields_for :companies do |company| %>

to

<% f.fields_for :companies_attributes do |company| %>

and i'm no longer getting the "expected object, but got array error",
now i'm getting
"undefined method `stringify_keys' for "test":String" where "test" was
the company name i inputted into the form. Below is the html output of
the form.

    <form action="/users" class="new_user" id="new_user" method="post">
    <p><label for="First_name">First name</label>
    <input id="user_firstname" name="user[firstname]" size="30"
type="text" value="" /></p>

    <p><label for="Surname">Surname</label>
    <input id="user_surname" name="user[surname]" size="30" type="text"
value="" /></p>

    <p><label for="email">Email</label>
    <input id="user_email" name="user[email]" size="30" type="text" /></

    <p><label for="password">Password</label>
    <input id="user_password" name="user[password]" size="30"
type="password" /></p>

    <p><label for="password_confirmation">Confirm Password</label>
    <input id="user_password_confirmation" name="user
[password_confirmation]" size="30" type="password" /></p>

    <hr />
    <h2>Company Information</h2>

      <input id="user_companies_attributes_name" name="user
[companies_attributes][name]" size="30" type="text" />

    <p class="submit"><input name="commit" type="submit" value="Sign
up" /></p>
    </form>