Rails two related models in one form not saving - ruby-on-rails-3

Question

My form fields are:
<%= form_tag signup_path, :class=>"no-ajax form-signin" do %>
<fieldset>
<legend>Company</legend>
<div class="field">
<label>Company Name</label>
<%= text_field :company, :name, :class => "input-block-level" %>
</div>
<%= hidden_field :company, :accounttype_id, :value => 2 %>
</fieldset>
<fieldset>
<legend>User</legend>
<div class="field">
<label>First Name</label>
<%= text_field :user, :first_name, :class => "input-block-level" %>
</div>
<div class="field">
<label>Last Name</label>
<%= text_field :user, :last_name, :class => "input-block-level" %>
</div>
<div class="field">
<label>Email</label>
<%= text_field :user, :email, :class => "input-block-level" %>
</div>
<div class="field">
<label>Role</label>
<%= text_field :user, :role_id, :value => 2 %>
</div>
</fieldset>
<fieldset>
<div class="field">
<label>Password</label>
<%= text_field :user, :password, :class => "input-block-level" %>
</div>
<div class="field">
<label>Confirm Password</label>
<%= text_field :user, :password_confirmation, :class => "input-block-level" %>
</div>
</fieldset>
<div class="form-actions">
<%= submit_tag 'Sign Up', :class => "btn btn-large btn-success btn-block" %>
</div>
<% end %>
My controller for the form is:
def signup
#company = Company.new
#user = #company.users.build
if #company.save
redirect_to :action => 'success'
else
render :action => 'signup'
end
end
When I save, it says that it fails.
This is the data that was posted (pasted from the rails console):
{"utf8"=>"✓", "authenticity_token"=>"9y4JeSvm34P05FBKbP3D3aToHlwejFZBkSyPbmGMJrk=", "company"=>{"name"=>"Test Co", "accounttype_id"=>"2"}, "user"=>{"first_name"=>"Andy", "last_name"=>"Bernard", "email"=>"andy#testco.com", "role_id"=>"2", "password"=>"[FILTERED]", "password_confirmation"=>"[FILTERED]"}, "commit"=>"Sign Up"}
What is the form unable to save
is there a better way to do this process? (create new Company, then create user linked to that company, all in one form)

Answer 1

The signup action in your controller does not save #company because no attributes were passed when Company.new was called.
#company = Company.new(params[:company])
will pass the parameters "company"=>{"name"=>"Test Co", "accounttype_id"=>"2"}.
Likewise for "user"=>{...}:
#user = #company.users.build(params[:user])
For an all-in-one form, Rails provides the following method accepts_nested_attributes_for which allows you to create both the company and the user in one go.