Hey guys, I've been beating my head against a wall with a particular use case for nested forms (I'm using Rails 2.3.5).
Essentially I have Project and Payment models that looks like this
class Project < ActiveRecord::Base
has_many :payments
end
class Payment < ActiveRecord::Base
belongs_to :project
accepts_nested_attributes_for :project
end
I'm also using nested routing for these two resources:
map.resources :projects do |project|
project.resources :payments
end
I'm trying to use a nested form to allow the user to modify certain attributes of the Project when creating a new Payment. So if the Project has a title, for example, the view for creating a new Payment would look like this:
<% form_for([@project, @payment]) do |f| %>
<% f.fields_for :project do |project_form| %>
<%= project_form.label :title %>
<%= project_form.text_field :title %>
<% end %>
<%= f.text_field :credit_card_number %>
...
<% end %>
The Payments controller is pretty much standard:
class PaymentsController < ApplicationController
before_filter :load_project
# GET /payments/new
# GET /payments/new.xml
def new
@payment = @project.payments.build
respond_to do |format|
format.html # new.html.erb
format.xml { render :xml => @payment }
end
end
# POST /payments
# POST /payments.xml
def create
@payment = @project.payments.build(params[:payment])
respond_to do |format|
if @payment.save
flash[:notice] = 'Payment was successfully created.'
format.html { redirect_to([@project, @payment]) }
format.xml { render :xml => @payment, :status => :created, :location => @payment }
else
format.html { render :action => "new" }
format.xml { render :xml => @payment.errors, :status => :unprocessable_entity }
end
end
end
private
def load_project
@project = Project.find(params[:project_id])
end
end
What I'm finding is that on the new Payment form, I'm ending up with something like this:
<input id="payment_project_attributes_title" name="payment[project_attributes][title]" size="30" type="text" />
<input id="payment_project_attributes_id" name="payment[project_attributes][id]" type="hidden" value="56" />
(Note the automatically created #payment_project_attributes_id)
When the form is submitted, rails receives this like so (bear in mind that Project #56 already exists):
"payment"=>{"project_attributes"=>{"title"=>"test title", "id"=>"56"}, "credit_card_number"=>"41111111111111111"}
And here's the problem: when this is run through the controller, it DOESN'T apply the title attribute to the Payment's Project.
What's strange is that if I remove that "id"=>"56", the Project's title IS updated. Here's an example using the console:
ruby-1.8.7-p249 > Project.find(56)
=> #<Project id: 56, title: nil, created_at: "2010-06-18 15:58:25", updated_at: "2010-06-18 16:01:37">
ruby-1.8.7-p249 > p=Project.find(56).payments.new({"project_attributes"=>{"title"=>"my new title", "id"=>"56"}})
=> #<Payment id: nil, project_id: 56, created_at: nil, updated_at: nil>
ruby-1.8.7-p249 > p.project
=> #<Project id: 56, title: nil, created_at: "2010-06-18 15:58:25", updated_at: "2010-06-18 16:01:37">
ruby-1.8.7-p249 > p=Project.find(56).payments.new({"project_attributes"=>{"title"=>"test title"}})
=> #<Payment id: nil, project_id: 56, created_at: nil, updated_at: nil>
ruby-1.8.7-p249 > p.project
=> #<Project id: nil, user_id: nil, title: "test title", created_at: nil, updated_at: nil>
(Note that the second payments.new, without the ID, causes p.project.title to be updated)
This seems directly contradictory to this ticket: https://rails.lighthouseapp.com/projects/8994/tickets/3687-nested-attributes-with-belongs_to-only-supports-one-use-case
Does anybody have any thoughts?
I should note that what I'm really trying to do is one layer more complex--I'm trying to update user_attributes for Project (using a belongs_to :user/accepts_nested_attributes_for :user on the Project) but I'm sort of hoping that will just work if I can figure this out.